Volume 7 Supplement 1

Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

Open Access

Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

Clinical and Translational Allergy20177(Suppl 1):10

DOI: 10.1186/s13601-017-0142-2

Published: 30 March 2017

ORAL ABSTRACT SESSION 1: Food allergens • Anaphylaxis

OP01 Fatal anaphylaxis is decreasing in France: analysis of national data, 1979–2011

Guillaume Pouessel1,2,3, Claire Claverie4, Julien Labreuche5, Jean-Marie Renaudin3,6, Aimée Dorkenoo4, Mireille Eb7, Anne Moneret-Vautrin6, Antoine Deschildre2,3, Stephane Leteurtre4

1Department of Pediatrics, Children’s Hospital, Roubaix, France; 2Division of Pulmonology and Allergology, Department of Pediatrics, Faculty of Medicine and Children’s Hospital, Lille, France; 3Allergy Vigilance Network, Vandoeuvre les Nancy, France; 4Université Lille 2, CHU Lille, EA 2694 - Santé Publique: épidémiologie et qualité des soins, Lille, France; 5Biostatistic Unit, Maison Régionale de la Recherche Clinique, CHRU Lille, Lille, France; 6Department of Allergology, Emile Durkheim Hospital, Epinal, France; 7Centre d’Epidémiologie sur les Causes Médicales de Décès INSERM, CHU de Bicêtre, Le Kremlin-Bicêtre, France

Correspondence: Guillaume Pouessel - guillaume.pouessel@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):OP01

Introduction: Incidence of anaphylaxis is increasing. Data regarding anaphylaxis mortality are limited, but conflicting. Our objective was to document anaphylaxis mortality rate (deaths per million population), time trends and specificities according to triggers (iatrogenic, venom, food, unknown), age groups, sex and geographical regions (North and South) in France, between 1979 and 2011.

Methods: Data were obtained (1) from database of the National Mortality Center (CEPIDC) to collect cases in which anaphylaxis was included as a cause of death, sex, age, and geographic region of death, (2) from the database of the National Institute for Economical and Statistical studies (INSEE) to define the referent populations. We used a multivariable log-linear Poisson regression model to assess the impact of time period, age, sex and geographic region on anaphylaxis deaths.

Results: During the period study, 1603 deaths were collected: 1564 in adults and 39 in children (age <18 year). The overall prevalence of anaphylaxis fatalities was 0.84 per million population (95% IC 0.80–0.88), ranging from 0.08 per million (95% IC 0.05–0.10) in pediatric population to 1.12 per million (95% CI 1.06 to 1.17) in adult population. Annual percentage change for case fatality rate was −2.0% (95% CI −2.5 to −1.5; p < 10−4) indicating a decrease in case fatality rate during the study period. Anaphylaxis fatality rate was higher in men (1.08 per million [95% IC 1.00 1.16] than women (0.86 per million [95% IC 0.80–0.92]) (p < 10−4). Triggers of anaphylaxis fatalities were iatrogenic (63%), mostly drugs, venom (14%) and food (0.6%). Unspecified anaphylaxis was frequent (23%). The highest rate was in persons aged >70 years (3.50 per million population per year [95% IC 3.25–3.76]) and the lowest in the pediatric population (p < 10−4). Only venom-induced mortality rate was higher in South of France (0.16 per million [95% IC 0.13–0.19]) compared with the North (0.11 per million [95% IC 0.09–0.13]) (p = 0.004). Only 8 food-induced fatalities were recorded (age <35 years in 7 cases).

Conclusion: Overall anaphylaxis mortality rate is decreasing over the three last decades in France. We confirm that iatrogenic causes are the most frequent causes. Older age and male sex are risk factors of fatal anaphylaxis of any cause except for food-induced anaphylaxis.

OP02 Diagnostic workup after severe anaphylaxis

Linus Grabenhenrich1, Margitta Worm1, Sabine Dölle1, Kathrin Scherer2, Isidor Hutteger3

1Charité - Universitätsmedizin Berlin, Berlin, Germany; 2University Hospital Basel, Basel, Switzerland; 3Universitätsklinikum Salzburg, Salzburg, Austria

Correspondence: Linus Grabenhenrich - linus.grabenhenrich@charite.de

Clinical and Translational Allergy 2017, 7(Suppl 1):OP02

Introduction: After a severe anaphylactic reaction, a diagnostic workup is recommended to confirm or rule out the elicitor(s) in question. The type of diagnostic chosen is usually based on the elicitor and severity of the reaction and might follow local experiences. We aimed to describe elicitor-specific diagnostic habits in the workup of severe anaphylaxis, comparing European countries.

Methods: The Network for Online Registration of Anaphylaxis (NORA) collected details about elicitors, symptoms and severity, treatment and the diagnostic workup of patients who experienced at least one episode of severe anaphylaxis, as documented within medical records of participating tertiary referral centres.

Results: Between June 2011 and April 2016, the registry collected data for 6465 cases of severe anaphylaxis, 74% of which reported to know the elicitor, with a remaining 20% having only a suspicion and 6% cases of idiopathic anaphylaxis. The allergen was known and confirmed by a diagnostic test in 4410 (92% of known elicitors). Of these, 68% had a reaction to this allergen for the first time, and 32% reported at least one earlier reaction to the same allergen. In first-time reactors (n = 3001) 7% reported that the allergen was confirming by a diagnostic test already before this reaction, for food 14%, insects 3%, drugs 2%, and 80% for SIT-induced anaphylaxis. Of cases with recurrent anaphylaxis (n = 1409), 30% had a test confirming the allergen before the reported reaction, for food 44%, insects 16%, drugs 18%, and 91% for SIT-induced anaphylaxis. Of all diagnostically confirmed cases of food-induced anaphylaxis (n = 1555), 78% were assessed by a skin test (SPT, positive in 93%), 90% by specific IgE (sIgE, 94% positive), 27% tryptase (7% positive), and 13% underwent an oral food challenge (positive in 88%). Patients with anaphylaxis caused by drugs had the following tests (positives of these): SPT 88% (49%), sIgE 31% (46%), tryptase 48% (11%), and provocation 19% (68%). For reactions against insect venom: SPT 79% (84%), sIgE 98% (97%), and tryptase 93 (8%). Irrespective of the elicitor, SPTs were performed more often in Austria, Ireland and Greece (92, 96, and 99%, respectively), and less often in Italy (64%). Tryptase was almost never measured in Ireland, Greece and France, whereas determination of specific IgE was carried out similarly between European countries.

Conclusion: The choice of diagnostic measure depended on the elicitor and varied by country. Especially the assessment of tryptase is handled very differently between allergens in question and countries. These differences may indicate aspects of the diagnostic workup with a certain degree of ambiguity, which might benefit from further harmonization.

OP03 Primary sensitisation versus co-sensitisation to hydrolysed wheat protein

Morten Christensen, Carsten Bindslev-Jensen, Charlotte Mortz

Department of Dermatology and Allergy Centre, Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark

Correspondence: Morten J. Christensen - morten.junker.christensen@rsyd.dk

Clinical and Translational Allergy 2017, 7(Suppl 1):OP03

Introduction: Wheat protein is responsible for various phenotypes of allergic diseases. More recently an increased number of immediate type 1 allergic reactions to hydrolyzed wheat proteins (HWP) have been reported.

The aim of this study was to characterize the clinical profile and evaluate patients with a case-history of anaphylaxis related to ingestion of a product containing HWP. Furthermore, to describe patients with other types of wheat allergy co-sensitized for HWP.

Methods: From May 2010 to August 2015 we investigated 56 patients (31 female, 25 male, mean age 39.0 years [1.5–77.2]) sensitized to commercialized HWP, either by specific immunoglobulin E (sIgE) (ThermoFischer, Uppsala, Sweden) and/or skin prick test (SPT). Based upon case-history patients were divided into 3 groups: (1) allergic reaction to ingestion of a HWP containing product (n = 9) (2) ingestion of a wheat product; WIA (n = 19), (3) ingestion of a wheat product in combination with exercise; WDEIA (n = 28). All patients were orally challenged with the incriminated food.

Results: The total positive rate of sIgE to HWP was 47/56 (83.9%), SPT 35/42 (83.3%) and BHR 22/42 (52.3%). Fourteen patients were triple positive to commercialized HWP of whom 7/9 patients in the HWP group. In total 9 (16%) patients were identified with a case-history of anaphylaxis related to a HWP containing product. Seven of 9 had a case-history to the same hydrolyzed wheat product (AMO Letbagt®). The average serum level of HWP-sIgE and the SPT were higher in patients with a case-history of HWP, respectively (median 5.3 kU/L ±6.8) (p < 0.05) and (median 6.0 mm ±4.1) (p < 0.05) compared to the WIA and WDEIA groups. A complete negative pattern was determined with specific wheat proteins normally associated with other phenotypes of wheat allergy, omega-5 gliadin (f416), gliadin (f98), High Molecular Weight (Tri a 26) and α-amylase trypsin inhibitor (Tri a 30). Basophil histamine release (BHR) for HWP was extremely positive in 8/9 HWP patients with activity retained to dilutions up to 10−12. The most striking finding was the ultrahigh sensitivity of BHR in diagnosing allergy to HWP. It is, however, interesting, that the HWP patient tolerates ingestion of unmodified wheat.

Conclusion: Reactivity to HWP seems to be confined to patients specifically sensitized to this heterogeneous group of products without concomitant allergy to normal wheat. Irrelevant co-sensitization is also seen in classical wheat allergy.

OP04 Actual adrenalin treatment in a specialised clinical setting, compared to administration as recommended by a built-in algorithm in a severity scoring instrument in food allergy

Esben Eller, Henrik Fomsgaard Kjaer, Charlotte Mortz, Carsten Bindslev-Jensen

Odense University Hospital, Odense, Denmark

Correspondence: Esben Eller - esben.eller@rsyd.dk

Clinical and Translational Allergy 2017, 7(Suppl 1):OP04

Introduction: One of the most used severity scoring instruments, the Sampson 1–5, includes a built-in algorithm indicating symptoms which necessitate adrenalin administration. These include grade 5 anaphylactic symptoms, but also grade 3 and 4 such as laryngeal “puritus, tightness, or dysphagia” and lower respiratory symptoms such as “wheezing, dyspnea or cyanosis”. Our aim was to compare the recommended adrenalin administration with the actual administration in our clinic in relation to the underlying eliciting symptom.

Methods: Data from 2382 positive food challenges (mean age 11.6 years [range: 0.5–74.1y]) performed between Jan. 2000 and Dec. 2015 at the Allergy Centre, Odense, Denmark were included, and severity of reactions was assessed using the Sampson 1–5 severity instrument. All patients were evaluated by experienced specialists during challenge. Actual medications administered during the challenges, i.e. adrenalin, β2-agonist, corticosteroid, or antihistamine were compared with recommended adrenalin treatment according to the algorithm in Sampson 1–5.

Results: Out of 346 challenges scored as grade 4 anaphylaxis, 296 were terminated due to respiratory symptoms requiring adrenalin according to Sampson 1–5, i.e. “barky cough, hoarseness, difficulty swallowing” (laryngeal, n = 79), “wheezing, dyspnea, cyanosis” (lower resp. n = 181) or both (n = 36). Nine of the 115 patients with laryngeal symptoms were treated with adrenalin, all due to inspiratory stridor. No patients with lower respiratory symptoms received adrenalin, but the majority were treated with β2 agonists (188/217), whereas in 30 challenges, symptoms disappeared without treatment or only antihistamine for concomitant urticaria were used. Patients solely with laryngeal symptoms received β2-agonists in 16 challenges, but the majority of them (54/79) received no treatment or only antihistamine. The 36 patients with both laryngeal and lower respiratory symptoms were treated in same manner as patients with only lower respiratory symptoms, i.e. β2 agonist for their bronchial wheeze or asthma. Grade 5 anaphylaxis was seen in 11 challenges, 1 caused by non-adrenalin recommended “loss of bowel control”. In the remaining 10 cases, 7 patients were treated with adrenalin, either due to “hypotension < 90 mm Hg” (n = 3) or “unconsciousness” (n = 4). Three children fainted, but regained consciousness without administration of adrenalin. Grade 5 anaphylaxis should almost always be treated with adrenalin, whereas adrenalin only was administrated to inspiratory stridor and not to bronchial expiratory wheeze or asthma in grade 4 anaphylaxis. Respiratory signs were instead medicated according to symptoms, i.e. with β2-agonist to relieve bronchoconstriction. All patients were evaluated by experienced specialists, and therefore this practice should be addressed with care in less experienced settings.

Conclusion: Inspiratory stridor was the main cause of adrenalin treatment in grade 4 anaphylaxis, whereas the majority of lower respiratory symptoms were treated with inhalant β2 agonists, thereby overcoming the need for adrenalin. This needs to be considered in future treatment recommendations.

OP05 Do patients know how to use adrenaline auto-injectors?

Leonor Carneiro-Leão, Jenny Badas, Luís Amaral, Alice Coimbra

Serviço de Imunoalergologia, Centro Hospitalar de São João, Porto, Portugal

The first two authors have equal contribution.

Correspondence: Leonor Carneiro-Leão - leonorcarneiroleao@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):OP05

Introduction: Adrenaline auto-injectors (AAI) are the first line treatment for anaphylaxis in community settings. Two are currently available in Portugal (Anapen® and Epipen®).

Our aim was to evaluate patient’s ability to properly use AAIs; impact of device switching and patients’ preferences.

Methods: Patients who had been prescribed an AAI in our department were invited to demonstrate correct technique of AAI by simulating adrenaline administration using training devices. First, simulation with their prescribed AAI; second, evaluation of device switching, without any previous training, by simulating injection with a different AAI (Epipen® or Anapen®, as well as Emerade®-currently unavailable in Portugal). Finally, they were asked which device they liked the best.

Results: Thirty-two patients were enrolled, 16 (50%) females, with a mean (SD) age of 42.9 (±15.8) years; 18 (56%) with hymenoptera venom allergy and 14 (44%) food allergy. Anapen® was prescribed to 15 (47%) and Epipen® to 17 (53%). Six did not acquire any AAI; 21 (66%) admitted carrying it on a daily basis. Eleven (34%) could not demonstrate successful adrenaline administration with their prescribed AAI, 5 with Anapen® and 6 with Epipen®. Nine (60%) of the 15 patients who were prescribed an Anapen® could not administer adrenaline with an Epipen®; 11 (65%) of the 17 with a prescribed Epipen® were unable to use an Anapen®. Only 2 (6%) were incapable of properly managing an Emerade®. The most common error in patients switching from Epipen® to Anapen® was not removing the needle cap (9 patients). In the group switching Anapen® to Epipen®, the most common misuse was not massaging the injection site (10 patients); 6 tried to remove the orange tip as if it was a cap. The preferred AAI was Emerade® in 20 (63%) and Epipen® in 12 (37%).

Conclusions: Patients at-risk for anaphylaxis are provided with portable auto-injectors, educated and trained on their use. One-third of the patients did not always carry them. More than one-third was unable to successfully demonstrate adrenaline administration with their prescribed AAI. Almost two-thirds failed to simulate injection when switched to the alternative one available in Portugal without any training. Design appears to play a role in a successful switch since 94% of the patients changing from either Anapen® or Epipen® to Emerade® were able to correctly use it. It was also the overall preferred auto-injector. These emergency medical devices should be patient friendly.

OP06 Incidence, clinical features, triggers and management of anaphylaxis in the Pediatric Emergency Department of the Tel Aviv Medical Center

Dikla Pivko Levy1, Moshe Ben-Shoshan2, Ayelet Rimon1, Shira Benor1

1Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; 2Montreal Children’s Hospital, Montreal QC, Canada

Correspondence: Dikla Pivko Levy - diklapivko@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):OP06

Introduction: Anaphylaxis is a severe, life threatening systemic hypersensitivity reaction. The diagnosis of anaphylaxis is not always easy to make in the pediatric emergency department (ED) setting. Therefore, children are often dangerously underdiagnosed and undertreated. There is sparse information on the incidence and triggers of anaphylaxis in Israel.

Our objective was to assess the true incidence of anaphylaxis treated in the Pediatric ED, to identify triggers associated with anaphylaxis, to describe the management of anaphylactic reactions and identify potential gaps in diagnosis and treatment.

Methods: A retrospective chart review of cases presenting to the Pediatric ED of the Dana-Dweck Children’s hospital, at the Tel Aviv Sourasky Medical Center between January 1st 2013 to December 31th 2014, with a diagnosis of anaphylaxis or allergic reaction. The clinical features, causative agents, treatment administered and recommendations at discharge were recorded.

Results: During the study period, there were a total of 56,596 visits to the ED. 437 patients were diagnosed with an allergic or anaphylactic reaction. Of these 59 (13.5%) met the diagnostic criteria for anaphylaxis, but only 22 were given the correct diagnosis. The mean age of presentation was 6.9 years, with a male predominance of 66%. Food was the most common causative agent (78%). Specifically, exposure to treenuts (28% (and cow milk (24%) were responsible for a majority of the cases. The majority of children (78% (had known food allergies and presented with breathing difficulties (64%), followed by urticaria (62%). Twenty children (37.7%) were treated with IM adrenaline prior to ED arrival and only fifteen (26%) were treated with IM adrenaline in the ED. Most of the children (86%) were discharged home. Almost 30% were discharged without a prescription to an automated Adrenaline injector.

Conclusion: The rate of anaphylaxis in the study period was 0.1% of all visits to the pediatric ED. Most cases of anaphylaxis were underdiagnosed. As a result, treatment guidelines regarding the use of IM Adrenalin were not always followed and many children were discharged without a prescription for an adrenaline auto-injector.

ORAL ABSTRACT SESSION 2: Clinical aspects • Diagnosis and treatment

OP07 Almond allergy in a cohort of Dutch atopic children: results from 189 oral food challenges with almond

Nicolette J. T. Arends1, Nikki Edelbroek1, Hans de Groot2, Joyce A. M. Emons1, H. Kim A. Brand1, Dirk Verhoeven2, Leonieke N. van Veen2, Nicolette W. de Jong1

1Erasmus MC Sophia Children’s Hospital - Kinderhaven, Rotterdam, the Netherlands; 2Pediatric Department, Reinier de Graaf Groep, Delft, the Netherlands

Correspondence: Nicolette J. T. Arends - n.arends@erasmusmc.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):OP07

Introduction: Tree nut allergies are common in children, whereas most reported allergic reactions are caused by hazelnut and cashew nut [1,2]. Reactions to these nuts may vary from mild oral allergy symptoms to anaphylaxis. Not much is known about the frequency and severity of almond allergy in children. We therefore evaluated the results of oral food challenges with almond in a large group of Dutch atopic children.

Methods: All open and double-blind placebo-controlled food challenges (DBPCFC) with almond, performed between 2009 and 2015 in two Dutch outpatient clinics were evaluated retrospectively. Skin prick tests (SPT) with almond were performed in most children. Information about previous reactions, reasons for avoidance of almond and presence of atopic diseases (eczema, asthma, allergic rhinitis) were taken from the medical records.

Results: A total of 189 almond challenges were analyzed. Median age of the children was 7.5 years (range 2.0–17.8 years). Almond was removed from the diet for the following reasons: a previous reaction to almond (3.7%), previous reaction to another nut (30.7%), previous reaction to peanut (22.2%), other food allergies (23.8%), a positive test (sensitization) to almond (12.2%), eczema (3.7%), allergic parents (1.1%) and unknown (2.6%). A positive SPT almond was found in 148 children (78.3%). SPT was negative in 28 children (14.8%) and not performed in 13 children (6.9%). 97/101 DBPCFC’s were negative, 2/101 children had a mild reaction and 2/101 children had a doubtful reaction. 86/88 open challenges were negative, 1 child had a mild reaction and 1 child had a doubtful reaction. Reactions were treated with antihistamine. No correlation was found between the outcome of the challenge and SPT results. Sensitization to birch pollen was found in 109 children (57.7%). Sensitization to almond is frequently found in Dutch atopic children. This study shows that most of these sensitizations appear to be clinically irrelevant. Only 6/189 children (3.2%) had a mild reaction and no anaphylaxis was seen. Sensitization might be explained partly by cross-sensitization with birch pollen.

Conclusion: In a large cohort of Dutch atopic children, almond allergy is extremely rare and allergic reactions are only mild.

References
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    McWilliam V, Koplin J, LodgeC, Tang M, Dharmage S, Allen K. The prevalence of tree nut allergy: a systematic review. Curr Allergy Asthma Rep. 2015;15:54.

     
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    Grabenhenrich L, et al. Anaphylaxis in children and adolescents: The European Anaphylaxis Registry. J Allergy Clin Immunol 2016;137:1128–37.

     

OP08 Oral tolerance induction using IFN-gamma in patients with anaphylactic food allergy (AFA), non-IgE-mediated food allergy (NFA) in atopic dermatitis (AD) and both AFA and NFA in AD

Geunwoong Noh1, Eun Ha Jang2

1Department of Allergy, Jeju Halla General Hospital, Jeju, Korea Republic; 2Department of Respiratory Medicine, Hanmaeum General Hospital, Jeju, Korea Republic

Correspondence: Geunwoong Noh - admyth@naver.com

Clinical and Translational Allergy 2017, 7(Suppl 1):OP08

Introduction: Food allergy is assessed generally by IgE-mediated laboratory tests. For NFA, gastrointestinal allergy is mainly considered. However, NFA which appears as eczema in atopic dermatitis is also frequent. In this report, typical three groups for food allergy was presented, patients with anaphylactic food allergy (AFA) as a representative IgE-mediated food allergy, patients with NFA which are presented as eczema in AD and patients who had both AFA and NFA in AD. Oral immunotherapy (OIT) using IFN-gamma was conducted successfully in these three groups. The different diagnostic and therapeutic approaches according to the type of food allergy and the clinical and immunological significance are presented.

Case report: Two patients had AFA. Specific IgE for causative foods like milk or eggs are very high and skin prick test for causative foods is also strong positive. AFA was confirmed by oral food challenges. Patients received OIT using IFN-gamma according to the protocol and finally they got the tolerance for causative foods completely. Five patients had food allergy which symptoms is appearing as eczema as AD. Specific IgE and skin prick test for causative foods were negative. Oral food challenges were performed and the appearance of the symptoms and signs of AD is confirmed and the diagnosis was made as NFA as causes of AD. Patients received OIT using IFN-gamma according to the relevant protocol, successfully. Two patients had NFA in AD and AFA. The some foods caused AD by showing eczematous reaction and the other different food provoked anaphylactic reactions, together. The specific IgE and skin prick test for the causative foods is very high for the food allergens of AFA and those for the foods were negative for NFA in AD. OFC was done for the causative foods of AFA and NFA. Patients received OIT using IFN-gamma by the compatible protocol according to the types of food allergy successfully.

Conclusion: Food allergy may be assessed by differentiation as food allergies of IgE- and non-IgE-mediated type. The diagnostic and therapeutic approaches are different according to the types of food allergy. The immunopathogenesis and clinical approach should be done according to the differential diagnosis.

Consent to publish: Written consent provided for publication of this abstract.

OP09 Predicting fish allergy outcome and assessing tolerance at home in a children’s population

Mariona Pascal1, Olga Dominguez2, Mònica Piquer2, Montserrat Alvaro2, Rosa Jimenez-Feijoo2, Jaime Lozano2, Adriana Machinena2, Maria del Mar Folqué2, Maria Teresa Giner2, Ana María Plaza2

1Immunology Department, CDB Hospital Clinic de Barcelona, Barcelona, Spain; 2Department of Allergy and Clinical Immunology, Hospital Sant Joan de Déu, Esplugues de Llobregat, Spain

Correspondence: Mariona Pascal - mpascal@clinic.ub.es

Clinical and Translational Allergy 2017, 7(Suppl 1):OP09

Introduction: Fish allergy is relevant in our pediatric population on a Mediterranean diet. Specific IgE (sIgE) tests aid in diagnosis, but oral food challenge is the gold standard. We sought to: (1) analyze the efficiency of sIgE to Gad c 1 and fish whole extracts to avoid challenge and (2) to evaluate maintenance of tolerance of challenged patients at home.

Methods: Children sensitized to fish and/or Gad c 1 reporting or not clinical history of fish allergy were challenged (masked single blind, 16 g protein for ≤12 year-old children and 22 g for older ones). Clinical history was reviewed and sIgE to Gad c 1, fish extracts (ImmunoCAP, ThermoFisher) and challenge test outcomes were analyzed. Tolerance at home was investigated.

Results: 83 patients (67.5% male, median [range] age at OFC: 8[2–15] years-old) were analyzed. 9.6% were only sensitized. Among those reporting symptoms, 26% were anaphylaxis, 43.4% urticaria, 4.8% atopic dermatitis, 8.4% gastrointestinal symptoms, 2.4% dyspnea. All patients were challenged. A total of 221 challenges were done: 71 canned tuna (CT), 72 fresh tuna (FT), 48 hake and 30 sole. Challenge was positive (OFC+) in 2.2% of patients for CT, 12.5% FT, 47.9% hake and 40% for sole. Gad c 1 sIgE was significantly higher in OFC+ patients for FT, hake and sole (p = .0031, <.0001, .0003, respectively) comparing with OFC-ones. Similarly occurred with sIgE to the corresponding extracts in the case of hake and sole (p = .0014 and .0015, respectively). ROC-curve analysis of Gad c 1 and whole extracts tests provided sIgE cut-offs to predict OFC+: Gad c 1: >37.5 kU/L for OFC with FT (AUC:0.80, LH:6.9), >4.7 kU/L for OFC with sole (AUC:0.91, LH:6.6), >3.5 kU/L for OFC with hake (AUC:0.88, LH:7.1). Tuna extract sIgE >15.5 kU/L for OFC with FT (AUC:0.78, LH:6.4), hake extract sIgE >23.5 kU/L for OFC with hake (AUC:0.83, LH:6.6), sole extract sIgE >1.1 kU/L for OFC with sole (AUC:0.89, LH:7).The follow up of tolerance at home showed that 64 (77.1%) patients were not eating the challenged food at home, 25 (39%) mainly for fear or refusal. A total of 49 reactions, of which 17 (34.7%) anaphylaxis, occurred in 39 patients (7 children with several fish species).

Conclusion: Certain sIgE cut-offs for Gad c 1, tuna, hake and sole extracts may aid in fish allergy diagnosis and predicting OFC outcome in our pediatric population. A significant proportion of children that tolerate fish at challenge, suffer allergic reactions when eating fish at home, some of them severe.

OP10 Development and validation of an app to monitor reactions during Oral ImmunoTherapy (OIT)

Paul Turner1, Nandinee Patel1, Marta Vazquez-Ortiz1, Sarah Lindsley1, Lucy Walker2, Simon Rosenberg2

1Imperial College London, London, United Kingdom; 2Illuminatis Ltd, London, United Kingdom

Correspondence: Nandinee Patel - paulyt@doctors.org.uk

Clinical and Translational Allergy 2017, 7(Suppl 1):OP10

Introduction: Until recently, food allergy management involved complete allergen avoidance, however, data now implies that this may not be required - for example, with regard to extensively heated egg or cow’s milk e.g. in cakes/biscuits. In many countries, oral immunotherapy (OIT) is used as a treatment modality for food allergy, particularly to cow’s milk and increasingly, peanut. However, adverse events are common (occurring in up to 80% of patients). There is a need to develop systems to facilitate safe OIT and allow real-time communication between patients and their treating allergist. Almost 90% of patients/parents now own a smartphone, which can be used to facilitate communication between patients and the clinical team.

Methods: We adapted a digital App called “Tell the Doctor” to allow real-time reporting of symptoms (adverse events, AEs) occurring outside the hospital environment. The App is being tested in an OIT trial in 46 peanut-allergic children. Focus groups were held to collect feedback from study participants, their parents, and members of the study team.

Results: The app was welcomed by both study participants and their families. Feedback was obtained relating to the following areas:
  • AE reporting was modified to allow rapid and instant alerts to the study team of any significant reactions occurring at home.

  • Neurological/behavioural changes were separated from cardiovascular symptoms, as there was no evidence that the former are related to the latter.

  • Study participants were asked to confirm OIT doses taken on a daily basis, thus confirming adherence to study protocol. Patients could also opt-in to a reminder service to prompt them to take both their OIT dose and any asthma preventer medicines by a time of their choosing.

Conclusion: The app facilitates real-time reporting of AEs during OIT studies and was preferred by participants and study team compared to delayed manual paper reporting. We expect electronic reporting to improve the data integrity of OIT-related AEs, and simplify AE reporting, thus improving safety. The advantages of using contemporary/popular communication modalities such as smartphone apps should be considered in the performance of OIT, whether in research or in clinical practice.

Acknowledgements: “Tell the Doctor” App funded by the Nominet Trust.

Trial registration: ClinicalTrials.gov Identifier: NCT02149719

Consent to publish: Informed consent was obtained, NHS HRA approval 15/LO/0287.

OP11 Introducing FABER test for allergy diagnosis: food molecule- and extract-based allergenic preparations in the newest and broadest nanotechnology IgE test

Adriano Mari1, Claudia Alessandri1, Ivana Giangrieco2, Lisa Tuppo2, Chiara Rafaiani1, Georg Mitterer3, Michela Ciancamerla1, Rosetta Ferrara1, Maria Livia Bernardi1, Danila Zennaro1, Maurizio Tamburrini2, Maria Antonetta Ciardiello2, Christian Harwanegg3

1Centri Associati di Allergologia Molecolare (CAAM), Rome, Italy; 2Istituto di Bioscienze e Biorisorse, Consiglio Nazionale delle Ricerche, Naples, Italy; 3MacroarrayDx, Vienna, Austria

Correspondence: Adriano Mari - adriano.mari@caam-allergy.com

Clinical and Translational Allergy 2017, 7(Suppl 1):OP11

Introduction: Multiplex tests allow to detect specific IgE to several different preparations at once. They allow patient’s profiling tailoring decisions for interventions. The last ten years have seen the availability of new technologies and when combined can lead to increase diagnostic information from allergy tests.

Our aim was to report about the FABER nanotechnology-based test in food allergy diagnosis.

Methods: FABER 244 IgE test is a new multiplexed in vitro test for specific IgE measurement having 122 molecular allergens and 122 allergenic extracts. Allergenic molecules and extracts, produced in house or obtained from top quality providers in the field, are coupled to chemically activated nanoparticles. Coupling is individually optimized to achieve maximum test performance providing high diagnostic accuracy for each spotted allergenic item. Once coupled they are arrayed to a solid phase matrix to form a one-step comprehensive array based testing solution, using 100 ul of patient serum or plasma.

Results: Extracts from 91 food-borne allergenic sources (fruits, vegetables, eggs, milks, meats, fishes, crustacean, mollusks, snails, mushrooms, anisakis) are arrayed together with 66 allergenic proteins obtained from the same sources. CCD-bearing proteins are included as markers to support test result interpretation, as well as allergenic molecular groups which cross-sectionally belong to food and inhalant sources. Extracts on FABER244 expand the panel overcoming missing of any not yet identified or available allergenic molecule, increasing diagnostic accuracy and comprehensiveness. Test interpretation is supported by CAAM Digital Reporting System (CDRS), a unique online tool available worldwide, allowing visualization on mobile devices of FABER test results. CDRS has been developed for patients to familiarize with the new extended molecule-based results. To be patient-friendly it uses local languages taking advantage of the Allergome platform as the multi-language source. Data on CDRS are shown with tables, graphs, images; comments are generated real time by experts using the Allergome and its external modules, InterAll and ReTiME.

Conclusion: FABER 244 is the most advanced in vitro test for specific IgE detection, including molecules and extracts. It makes available to the molecular allergist an unprecedented quantity of data. The inclusion of allergenic extracts is strategic to confirm or complement results obtained with the single allergenic molecules.

ORAL ABSTRACT SESSION 3: Experimental aspects • Food allergens

OP13 New developments in the allergenicity assessment of food derived from biotechnology

Antonio Fernandez1, Regina Selb1, Philippe Egenmann2, Michelle Epstein3, Karin Hoffmann-Sommergruber3, Frits Koning4, Martinus Lovik5, Clare Mills6, Javier Moreno7, Henk van Loveren8, Jean-Michel Wal9

1European Food Safety Authority, Parma, Italy; 2University Hospitals of Geneva, Geneva, Switzerland; 3Medical University of Vienna, Vienna, Austria; 4Leiden University Medical Center (LUMC), Leiden, the Netherlands; 5Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 6The University of Manchester (UNIMAN), Manchester, United Kingdom; 7Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain; 8Maastricht University, Maastricht, the Netherlands; 9Institut National de la Recherche Agronomique (INRA), Paris, France

Correspondence: Antonio Fernandez - antonio.fernandezdumont@efsa.europa.eu

Clinical and Translational Allergy 2017, 7(Suppl 1):OP13

Introduction: The European Food Safety Authority (EFSA) and other international bodies (Codex) define approaches for allergenicity assessment of food and feed derived from biotechnology. As an outcome of the allergenicity assessment, risk assessors estimate whether the novel protein is likely to be allergenic and whether the food derived from biotechnology is likely to be more allergenic than that derived from its appropriate comparator(s). Because it is challenging to predict the allergenicity of novel proteins, a weight-of-evidence approach is used to provide the assessor with a cumulative body of evidence to (a) reduce the uncertainty linked to the allergenicity assessment and, (b) enhance the reliability of predictions regarding the allergenic potential of novel protein(s).

Methods: Currently, EFSA is developing supplementary guidance to better define and clarify specific aspects of the allergenicity assessment requirements. In particular, (i) non-IgE-mediated immune adverse reactions to foods; (ii) in vitro protein digestibility; and (iii) endogenous allergenicity, are addressed.

Results: Firstly, celiac disease is a well characterised non-IgE-mediated adverse immune reaction to food, and the food proteins involved, as well as the underlying molecular mechanisms, have been described in detail. Secondly, the outcome of in vitro protein digestibility studies is considered relevant information in the weight-of-evidence approach. To date, the “pepsin resistance test” is commonly accepted for the safety assessment considerations by risk assessors. However, EFSA has previously highlighted its limitations for the allergenicity assessment as well as for its capacity to reflect in vivo digestion conditions. Thirdly, high performance methodologies for protein identification and quantification are available for endogenous allergenicity.

Conclusion: Firstly, based on the current knowledge EFSA is working on defining a strategy to be followed for the assessment of novel proteins’ potential to cause celiac disease. Secondly, EFSA is proactively developing a complementary strategy in order to reduce the resulting uncertainty in the allergenicity assessment. This strategy will be based on state-of-the-art in science, aiming at proposing an enhanced and refined in vitro gastrointestinal digestion test where different physiological conditions will be taken into consideration and more informative read-out procedures will be recommended. Thirdly, high performance methodologies for protein identification and quantification will be proposed as complementary/alternative methods to those based on human sera for the assessment of endogenous allergenicity within the comparative assessment analysis.

OP14 Why mice orally sensitised to OVA using antiacids react anaphylactic or not: possible explanation by colonisation with distinct bacterial strains

Susanne Diesner1,2, Cornelia Bergmayr1, Barbara Pfitzner3, Vera Elisabeth Assmann1, Philipp Starkl1, David Endesfelder4, Thomas Eiwegger2,5, Zsolt Szepfalusi2, Heinz Fehrenbach6, Erika Jensen-Jarolim1,7, Anton Hartmann3, Isabella Pali-Schöll1,7, Eva Untersmayr1

1Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria; 2Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria; 3Research Unit Microbe-Plant Interactions, Research Group Molecular Microbial Ecology, Department of Environmental Sciences, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; 4Scientific Computing Research Unit, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany; 5Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, Department of Pediatrics, Hospital for Sick Children, Research Institute, Physiology and Experimental Medicine, University of Toronto, Toronto ON, Canada; 6Priority Area Asthma & Allergy, Research Center Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany; 7Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University Vienna and University of Vienna, Vienna Austria

Correspondence: Eva Untersmayr - eva.untersmayr@meduniwien.ac.at

Clinical and Translational Allergy 2017, 7(Suppl 1):OP14

Introduction: In an oral mouse food allergy model, concomitant gastric acid suppression is associated with formation of antigen-specific IgE and anaphylaxis. Notably, we repeatedly observed non-responder animals protected from food allergy. Therefore, in this study we aimed to analyse the reasons for this protection.

Methods and Results: Out of 64 BALB/c animals being subjected to the oral ovalbumin (OVA) immunization protocol under gastric acid-suppression, 10 animals (16%) did not show any elevation of OVA-specific IgE or IgG1 titers indicating protection from allergic sensitization. In these animals, allergen challenges confirmed reduced antigen uptake and lack of anaphylactic symptoms, while in the non-protected allergic mouse group high levels of mouse mast cell protease-1 (mMCP-1) and a drop of core body temperature were elicited, indicative for anaphylaxis. Further, significantly lower numbers of CD4+ T cells and regulatory T cells were detected in the non-responders, as well as significantly lower levels of IL-4, IL-5, IL-10 and IL-13 in supernatants from stimulated splenocytes, but comparable levels of IL-22. This was accompanied by significantly increased numbers of total lymphocytes and reduced numbers of monocytes, erythrocytes and hematocrit in the peripheral blood of the non-responders. Comparison of microbiota finally revealed differences regarding the composition of bacterial communities on single bacterial Operational Taxonomic Unit (OTU) level between protected and allergic mice.

Conclusion: These data clearly indicate that protection from food allergy development was associated with significantly reduced Th2 cytokine levels and IL-10, and increased numbers of blood cells in the periphery after anaphylaxis. Most importantly, analysis of single bacterial OTUs indicated that a distinct microbiota composition was associated with a non-responding phenotype in this mouse model. The data propose that also microbiota might decide on the extent of a food-anaphylactic response.

Acknowledgements: Supported by FWF grants P21884, P21577 and KLI284 of the Austrian science fund FWF. HF is supported by the Deutsche Forschungsgemeinschaft (Cluster of Excellence “Inflammation at Interfaces” EXC 306).

OP17 Allergy to fenugreek – A new food allergy in peanut allergic children in Sweden

Soren Wille1,2, Peter Meyer1

1Department of Pediatrics, Helsingborg Hospital, Helsingborg, Sweden; 2Department of Pediatric Allergy, Skåne Universiy Hospital, Malmö, Sweden

Correspondence: Soren Wille - sorenwille@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):OP17

Introduction: To study an increasing number of peanut allergic children with allergic reactions after having eaten food with curry or other mixed spices. All were sensitized to fenugreek (Trigonella foenum graeceum).

Methods: We have collected and reviewed data from 13 patients during the last 5 years from our outpatient allergy departments. Eleven had reacted to food with curry and 2 to food with fajitas spice mixture. All were sensitized to and regarded as allergic to fenugreek, an ingredient in both curry and the spice mixtures. Five reacted with an anaphylactic reaction. Six reported allergy symptoms such as urticaria, itching in the mouth, abdominal pain, vomiting and asthma.

Results: Mean age for the first reaction, when known, was 9 years. Seven boys and four girls. All 13 children were sIgE-positive to both fenugreek and to peanut as well as one or more of the recombinant peanut allergens Ara h 1, 2 or 3. Seven tested for Ara h 1 were all positive, in six of seven the dominant allergen was Ara h 1. The sIgE-results will be presented in detail. Our patients have not yet had a food provocation test. Fenugreek belongs to the Fabaceae plant family (legumes). The dried seeds are used whole or ground to a yellow powder after roasting, most commonly as a spice in curry and other mixed spices but also as an ingredient in a variety of food. In the literature fenugreek allergy was first described 1993, a case with occupational asthma. We have found only two reports about fenugreek food allergy. In Norway it is recommended to warn peanut allergic patients against food containing fenugreek and lupin. In Sweden there is no such warning either from our pediatric allergy society nor from The Swedish National Food Agency, but fenugreek as well as other peanut cross-reactive allergens are mentioned as a potential risk for allergic reactions. We plan to review of the history of reactions to curry or spices and add sIgE tests in follow up of our peanut allergic patients. The results may change our opinion about which advice to give to peanut allergic patients about fenugreek and mixed spices, eg curry.

Conclusion: For patients with fenugreek allergy and for cautious peanut allergic patients it is a problem that fenugreek is not on the list of ingredients that should be declared according to the food labelling directive from the European Union and The Swedish National Food Agency.

OP18 Pru p 7 is a major peach allergen in patients from Southern France

Caroline Klingebiel1, Jonas Lidholm2, Angelica Ehrenberg2, Jonas Östling2, Isabelle Cleach3, Jean-Louis Mège3,4, Joana Vitte3,4

1Laboratoire Montgrand, LBM Multisite SELDAIX - BIOPLUS, Marseille, France; 2Thermo Fisher Scientific, Uppsala, Sweden; 3Laboratoire d’Immunologie, Hôpital de la Conception, Assistance Publique Hôpitaux de Marseille, Marseille, France; 4Aix-Marseille Université, Marseille, France

Correspondence: Caroline Klingebiel - jvitte@hotmail.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):OP18

Introduction: To assess frequency and magnitude of IgE sensitization to Pru p 7 sIgE in patients complaining of peach allergy.

Methods: Sera from 117 outpatients (median age 20 years, range 4–74; 44% males) having undergone sIgE work-up for peach extract and commercial component-resolved diagnostics (ImmunoCAP 250, Thermo Fisher Scientific, Uppsala, Sweden) between February 2012 and June 2016 were assayed for sIgE to recombinant Pru p 7. The positivity threshold was set at 0.10 kUA/L.

Results: Of the 117 patient sera analysed, 111 (95%) tested positive to peach extract, 73 of which (66%) displayed sIgE reactivity to rPru p 7. In 45/68 (66%) cases, sIgE reactivity to Pru p 7 was isolated (no detection of sIgE to rPru p 1, rPru p 3, or rPru p 4). Among the 6 peach negative sera, one was found positive to rPru p 7 (0.81 kUA/L). Quantitative analysis showed that levels of sIgE in the study population were higher to Pru p 7 than to peach extract (median 5.5 vs 1.3 kUA/L, range 0.10 to 30.7 vs 0.10 to 52.4, p = 0.003, coefficient of correlation -0.12). 38/111 (32%) sera with detectable sIgE to peach extract did not display sIgE to rPru p 7, and 3 of these sera (peach sIgE 0.18 to 0.20 kUA/L) did not display sIgE to any of rPru p 1, rPru p 3, rPru p 4, or MUXF3. Pru p 7 has been reported as a major allergen in peach allergic patients from Spain and Italy, and Pru p 7 sensitization appears to correlate with a specific clinical presentation in Japanese patients. Here, we bring evidence that Pru p 7 is a major allergen in peach-sensitized patients from Southern France, including those with low sIgE to peach extract and seemingly independent of sIgE reactivity to peach components currently available for diagnostic testing. Significant association with cypress pollinosis and severe peach-induced allergy have been observed in rPru p 7 sensitized patients.

Conclusion: Pru p 7 is needed for comprehensive component-resolved diagnostics of peach allergy in Mediterranean patients. Pru p 7 sensitization may be a prognostic factor of peach allergy severity. From a pathophysiological perspective, Pru p 7 may shed light on the as-yet obscure relationship between peach and cypress pollen allergy in the Mediterranean region.

POSTER DISCUSSION SESSION 1: Food allergens • Anaphylaxis

PD01 Comparison of the lipid-binding capacity and immunoreactivity of Pru p 3 and Mal d 3

Roberta Aina1, Pawel Dubiela1, Sabine Pfeifer1, Merima Bublin1, Christian Radauer1, Piotr Humeniuk1, Stefan Kabasser1, Riccardo Asero2, Karin Hoffmann-Sommergruber1

1Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria; 2Clinica San Carlo, Paderno Dugnano, Italy

Correspondence: Roberta Aina - roberta.aina@meduniwien.ac.at

Clinical and Translational Allergy 2017, 7(Suppl 1):PD01

Introduction: nsLTPs are pathogenesis-related proteins (PR-14) with antimicrobial activity, and represent important plant food allergens, especially in fruits. Even if nsLTPs from different Rosaceae fruits are highly homologous and cross-reactive, they possess different allergenic potentials, the strongest for Pru p 3 (peach), probably a primary sensitizer. This study aims at investigating the differences between Pru p 3 and Mal d 3 (apple), in relation to lipid-binding capacity and immunoreactivity, and to evaluate how LTP-ligand interaction may affect IgE reactivity.

Methods: Proteins were produced in Pichia pastoris, their expression was monitored in the culture supernatants by SDS-PAGE and immunoblotting with anti-nsLTP antiserum. rLTPs were purified by IEC chromatography and analysed by MALDI-TOF MS. To assess the LTP-ligand binding, ANS displacement assay was performed with 7 different fatty acids (from C12 to C18), either saturated or unsaturated, at different concentrations (10–100 μM). The IgE reactivity of recombinant allergens, alone or in complex with selected ligands, was analysed by ELISA assay using allergic patients’ sera.

Results: Both rLTPs migrate in SDS-PAGE between 10 and 15 kDa. MS analysis confirmed the identity of the purified proteins, providing 9.138 kDa (rPru p 3) and 9.553 kDa (rMal d 3) and were recognized by anti-nsLTP antiserum. ANS assay showed a higher fluorescence in Pru p 3 (+15%) compared to Mal d 3 and some differences in protein/ligands binding. However, both proteins had higher affinity for unsaturated fatty acids (e.g. ~50% fluorescence reduction with 10 μM oleic acid). ELISA test also evidenced higher IgE reactivity for rPru p 3 with respect to rMal d 3, as well as differences between the rLTPs alone and in complex with ligands. Our results suggest that Pru p 3 and Mal d 3 have different IgE reactivity and affinity for the fatty acids tested, but both preferentially bind unsaturated fatty acids. This interaction has an effect on IgE binding, but at different extent for Pru p 3 and Mal d 3. This may be due to specific differences in their lipid-binding region.

Conclusion: Our preliminary data support the hypothesis of a role of specific food matrix components (e.g. fatty acids), in modulating specific IgE responses to different food allergens with antimicrobial activity.

Acknowledgements: Supported by Marie-Curie project CARAMEL 626572, and FWF grants SFB-F4603 and W1248 to KHS, SP and PD, respectively.

PD02 Apple, strawberry, hazelnut and tomato tolerance after one year of sublingual immunotherapy with LTP (Pru p 3) in patients with LTP-Syndrome

Gador Bogas1, Francisca Gomez1, Paloma Campo1, Maria Salas1, Inmaculada Doña1, Esther Barrionuevo1, Maria Auxiliadora Guerrero1, Cristobalina Mayorga2, Ana Prieto1, Domingo Barber3, Maria Jose Torres1

1Allergy Unit, IBIMA-Regional University Hospital of Malaga, Malaga, Spain; 2Research Laboratory, IBIMA-Regional University Hospital of Malaga, Malaga, Spain; 3Institute for Applied Molecular Medicine (IMMA), School of Medicine, Universidad CEU San Pablo, Malaga, Spain

Correspondence: Francisca Gomez - paquigomez.p@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD02

Introduction: One of the most frequent fruit and vegetable allergies in the Mediterranean area is non-specific-lipid transfer protein (nsLTP) syndrome where patients suffer allergies not only to peach but other plants-food related to nsLTPs. Specific immunotherapy (sIT) brings a new perspective to treat these patients however little is known whether sIT to one allergen can affect allergy to other plant-derived food. The aim was to evaluate the effect of sublingual immunotherapy (SLIT) with Pru p 3 (Pru p 3-SLIT) to other plants-derived-food in allergic patients to vegetable.

Methods: In a group of 36 patients with allergy to peach, 30 (83.3%) had allergies to other plants-food related. Plant-food allergies were evaluated by compatible clinical history, prick-prick to fresh fruit and ImmunoCAPIgE. After one year of treatment with (enriched-Pru p 3-SLIT) we evaluated reactivity to apple, hazelnut, strawberry and tomato by double blind placebo control food challenge (DBPCFC).

Results: In the total group of patients, 12 (33.3%) were allergic to apple, 4 (33.4%) had anaphylaxis, 5 (41.6%) urticaria and/or angioedema and three (25%) OAS. Four (11.1%) were allergic to hazelnut, from these 3 (75%) presented anaphylaxis and 1 (25%) urticaria and/or angioedema. Four (11.1%) to strawberry, all the patients presented OAS. Three (8.3%) were allergic to tomato, presenting anaphylaxis one patient (33.3%) and urticaria and/or angioedema 2 (66.75). Prick-prick with the culprit food was positive in all of the patients (100%). sIgE with apple, strawberry and tomato was positive in all the cases (100%). Hazelnut was positive in three (75%). After one year of SLIT all the patients tolerated tomato with peel and 100 gr of strawberries. Regarding reactivity to apple, 7 (58.3%) tolerated the whole apple with peel. Finally 2 patients (50%) tolerated 15 units of hazelnut. These results showed that a percentage of patients with clinical symptoms to other plants-food related to nsLTP that can tolerate this food after receiving enriched-Pru p 3-SLITduring one year. Enriched-Pru P 3-SLIT could be a good tool to improve the clinical symptoms in patients with LTP-Syndrome.

Conclusion: These data show clinical changes after the first year of treatment with enriched-Pru p 3-SLIT, not only to peach but also to other food allergens as apple, hazelnut, strawberry and tomato.

PD03 Identification and implication of allergenic PR10 protein from walnut in birch pollen associated walnut allergy

Annette Jamin1, Andrea Wangorsch1, Jonas Lidholm2, Barbara Ballmer3, Stefan Vieths1, Stephan Scheurer1

1Molecular Allergology, Paul-Ehrlich-Institut, Langen, Germany; 2Thermo Scientific, Uppsala, Sweden; 3Allergy Unit, Department of Dermatology, University Hospital Zürich, Zurich, Switzerland

Correspondence: Andrea Wangorsch - andrea.wangorsch@pei.de

Clinical and Translational Allergy 2017, 7(Suppl 1):PD03

Introduction: Beside hazelnut, the English walnut (Juglans regia) belongs to the most important allergenic tree nuts across Europe. So far, four walnut allergens (2S albumin, vicilin, nsLTP, 11S globulin) are listed in the official IUIS allergen database. Although an association of allergic reactions to walnut with birch pollen sensitization has been reported, no cross- reactive culprit walnut allergen has been described. The aim of the present study was to identify a Bet v 1-like protein in walnut and to investigate its allergenic properties.

Methods: Using a Bet v 1-homologous cDNA sequence from iron walnut leaves (KJ598787) as template, a cDNA encoding a corresponding protein from Juglans regia kernels (Jug r PR10) was cloned by RT-PCR and 5’RACE. Recombinant® Jug r PR10 protein was expressed in E. coli and purified by a two-step chromatographic procedure. Purity and secondary structure were analyzed by SDS-PAGE and CD spectroscopy. Specific IgE levels to walnut extract, rBet v 1 and rJug r PR10 were measured by ImmunoCAP™ in birch pollen allergics with concomitant allergy to walnut (n = 15), confirmed by a positive open or double-blind placebo-controlled food challenge test. The presence of natural Jug r PR10 in walnut extract was analyzed by IgE immunoblot competition experiments using rJug r PR10 as inhibitor.

Results: Jug r PR10 (KX034087) was 100% identical in amino acid sequence to KJ598787, 67% to Bet v 1.01 and up to 74% to PR10 proteins from fruits, e.g. Mal d 1 (apple), Pru av 1 (cherry) and Pru p 1 (peach). Recombinant Jug r PR10 displayed secondary structures similar to those of Bet v 1. Walnut sensitization was detected in 40% (6/15) and 47% (7/15) of the patients studied, by ImmunoCAP and skin testing, respectively. In contrast, 93% (14/15) were reactive to rJug r PR10 and 100% to Bet v 1. The Bet v 1 and Jug r PR10 specific IgE values correlated strongly (r2 = 0.93), even though lower IgE levels were observed for Jug r PR10 (median 12.9 kUA/L) than for Bet v 1 (median 21.5 kUA/L). The presence of an IgE-reactive PR10 protein in walnut kernels was confirmed by immunoblot inhibition.

Conclusion: According to the established criteria, the PR10 protein from English walnut qualifies as major allergen. Low diagnostic sensitivity of walnut extract for patients with birch pollen associated walnut allergy might be due to small amounts of Jug r PR10 in walnuts. Recombinant Jug r PR10 may therefore become a useful tool for component-resolved diagnosis.

PD04 Peptidomics of α-Gal carrying protein – Stability and allergenic properties

Danijela Apostolovic1, Jelena Mihailovic2, Maja Krstic1,2, Maria Starkhammar3, Tanja Cirkovic Velickovic2, Carl Hamsten1, Marianne van Hage1

1Department of Medicine Solna, Immunology and Allergy Unit, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden; 2Center of Excellence for Molecular Food Sciences, Faculty of Chemistry, University of Belgrade, Belgrade, Serbia; 3Department of Internal Medicine, Södersjukhuset, Stockholm, Sweden

Correspondence: Danijela Apostolovic - danijela.apostolovic@ki.se

Clinical and Translational Allergy 2017, 7(Suppl 1):PD04

Introduction: The mammalian carbohydrate galactose-α1,3-galactose (α-Gal) has shown to cause a novel form of food allergy, red meat allergy, where patients have severe allergic reactions several hours after red meat consumption. The number of diagnosed cases has increased significantly over the past few years and the α-Gal epitope is now an established clinically relevant glycan that should be taken into account in the diagnosis of food allergy. We have previously shown that red meat allergic patients have a selective IgE response to the pure α-Gal glycan that is unrelated to the carrier protein. The aim of this study was to explore the impact of digestion of α-Gal containing glycoproteins using a model system exposing the α-Gal containing protein bovine thyroglobulin to in vitro gastric digestion.

Methods: Bovine thyroglobulin was digested with pepsin. Digestion products were analyzed for stability and allergenic properties by SDS PAGE, immunoblot and ImmunoCAP using sera from ten red meat allergic patients, as well as with a peptidomics approach.

Results: During pepsinolysis of bovine thyroglobulin, a wide range of peptide bands could be observed during the first 10 min. Thereafter 14–17 kDa peptides remained stable during the whole gastric phase. The presence of the α-Gal epitope on the obtained peptides was demonstrated using an anti-α-Gal antibody as well as by IgE reactivity in sera from red meat allergic patients. The α-Gal peptides were able to inhibit at least 40% of the IgE-binding to bovine thyroglobulin (ImmunoCAP). The peptidomics approach showed that these peptides represent mostly internal and C-terminal parts of the protein, where a specific region from Arg1617 until Lys2230 contains complex type of glycans with the most potent IgE-binding α-Galactosyl residues. α-Gal containing food can elicit delayed severe allergic symptoms in red meat allergic patients. Here we show that peptides obtained after pepsinolysis of the model allergen, bovine thyroglobulin, contain α-Gal and remain stable during the whole gastric phase. Furthermore, these peptides contain specific α-Galactosyl recognition patterns and bind IgE from red meat-allergic patients.

Conclusion: The allergic response to α-Gal could depend on the type of α-Galactosyl residues on peptides obtained after gastric digestion, where complex type of glycans seems to have the most intense IgE-binding.

PD05 Allergen-specific IgE and basophil responses to Ara h 2 and Ara h 6 are good predictors of peanut allergy in children

Francine C. van Erp1, Edward F. Knol1, Hannah M. Kansen1, Bo Pontoppidan2, Yolanda Meijer1, Cornelis K. van der Ent1, André C. Knulst1

1University Medical Centre Utrecht, Utrecht, the Netherlands; 2Thermo Fisher Scientific, Uppsala, Sweden

Correspondence: Hannah M. Kansen - H.M.Kansen-2@umcutrecht.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD05

Introduction: Double blind placebo-controlled food challenge (DBPCFC) is the gold standard to diagnose peanut allergy. In children sensitized to peanut, the detection of allergen-specific IgE (sIgE) and/or basophil sensitivity to Ara h 2 and Ara h 6 could be an alternative way to predict clinical peanut allergy and thereby avoid burdensome and expensive challenges in part of the patients.

We aimed to prospectively evaluate the most accurate diagnostic approach in children with suspected peanut allergy using sensitization tests and the Basophil Activation Test (BAT) to peanut components, with focus on Ara h 2 and Ara h 6.

Methods: In this cross sectional prospective diagnostic study (January 2012–May 2015), a total of 83 children (mean age 8.4 years) with suspected peanut allergy underwent diagnostic evaluation for peanut allergy including DBPCFC. The diagnostic value of sensitization tests and the BAT in predicting (severe) peanut allergy was evaluated.

Results: Peanut allergy was confirmed in 48 (58%) children, including 15 (18%) with severe allergy. Ara h 2 and h 6 showed high discriminatory capacity in sIgE and BAT. Ara h 6 had significant higher diagnostic value than Ara h 2 in the BAT. With sIgE to Ara h 2 we could classify 62% of children correctly as tolerant or allergic, when subsequently adding the BAT using Ara h 2 and Ara h 6 we could increase this to 80%.

Conclusion: This study shows that Ara h 2 and h 6 are both strong predictors of peanut allergy. A stepwise approach including sIgE to Ara h 2 and subsequently the BAT to Ara h 2 and Ara h 6 is able to predict peanut allergic status in the majority of children.

PD06 How does thermal processing modulate the allergen profile and IgE reactivity of peanut?

Rebekah Sayers1, Helen Brown2, Adnan Custovic1, Angela Simpson1, Claire Mills1

1University of Manchester, Manchester, United Kingdom; 2Campden BRI, Chipping Campden, United Kingdom

Correspondence: Rebekah Sayers - rebekah.sayers@postgrad.manchester.ac.uk

Clinical and Translational Allergy 2017, 7(Suppl 1):PD06

Introduction: Peanuts are rarely consumed in their native form and are most commonly, fried or roasted, conditions which favour the formation of Maillard reaction products (MRP’s). Quantitative proteomic profiling of these modified proteins will enable MRP formation to be monitored during processing and markers identified. Thermal processing is also thought to modulate the allergenic activity of peanuts by causing protein aggregation and decreasing solubility. The IgE reactivity of thermally processed peanut proteins will be assessed using a panel of peanut-allergic patient serum.

Methods: Raw and processed peanuts were extracted under harsh denaturing conditions and subjected to proteomic profiling using data-dependent acquisition (DDA) on an Orbitrap Elite mass spectrometer. Data was processed using Progenesis-QI and peptides identified using a curated peanut database and a predetermined set of variable Maillard modifications in Peaks. Serum samples from peanut allergic patients were obtained from the Manchester Respiratory, Allergy and Thoracic Surgery (ManARTS) Biobank and IgE reactivity assessed by immunoblotting, inhibition ELISA and histamine release.

Results: Mass spectrometric analysis revealed processing-induced modification of peanut allergens through the formation of Maillard reaction products and reduced solubility through aggregation. Extensive boiling (>2 h) had complex effects on allergen structure, and caused hydrolysis of allergens, and loss of Ara h 2 into the cooking water. Patients could be classified into those who were sensitised to several allergens and reacted towards aggregates, and those sensitised only to Ara h 2. Many of the latter patients were not reactive to boiled peanuts.

Conclusion: This work has identified a number of peptide markers in peanut which are characteristic of different types of thermal processing. It also highlighted the ability of extensively processed protein to retain IgE reactivity in certain sensitised individuals whilst boiled peanuts maybe less reactive in certain patients. Boiled peanuts may provide an alternative for oral immunotherapy with reduced side-effects, especially in patients only reactive to Ara h 2.

PD07 Food induced anaphylaxis – Where did the food products come from and how much is consumed before reactions occur?

Sabine Dölle1, Linus Grabenhenrich2, Juliane Schulz1, Anne Moneret-Vautrin3, Margitta Worm1, Network for Online Registration of Anaphylaxis (NORA)

1Department of Dermatology and Allergology, Comprehensive Allergy Center Charité, Charité - Universitätsmedizin Berlin, Berlin, Germany; 2Institute for Social Medicine, Epidemiology and Health Economics, Charité - Universitätsmedizin Berlin, Berlin, Germany; 3The Allergy Vigilance Network, University Hospital Nancy, Nancy, France

Correspondence: Sabine Dölle - sabine.doelle@charite.de

Clinical and Translational Allergy 2017, 7(Suppl 1):PD07

Introduction: Food is one of the most common elicitors of anaphylaxis. Even small amounts of a food allergen can cause severe allergic reactions. Based on data from the NORA network, we aimed to analyze the source and amount of food ingested causing the anaphylactic episode.

Methods: The European data from the Network for Online Registration of Anaphylaxis (NORA) was analyzed, restricted to cases of food-induced anaphylaxis.

Results: 2204 cases of food-induced anaphylaxis were registered between June 2011 and April 2016. The detailed questions for food induced anaphylaxis were answered in 1460 cases. Of these, 843 cases occurred to non-packed foods, and 617 cases to pre-packed foods. For 744 the source of food elicitor was unknown. The origin of non-packed products was known in 72%, mostly from supermarkets (n = 116), buffets (n = 108) and catered foods (n = 105). The origin was known in 78% for pre-packed foods namely cereal bar, peanut puffs or hazelnut spread. The responsible food allergen was listed in the list of ingredients in 89%. The amount of food causing the reaction was documented in 60% of all cases, more often when children were affected. In children, one tea spoon was the most frequently estimated amount, and a plate in adults.

Conclusion: Both, non- and pre-packed foods were frequent sources of allergens causing anaphylaxis. Despite, the allergen was explicitly stated in the list of ingredients in the majority of pre-packed foods, anaphylaxis occurred. Therefore, labelling alone is not sufficient to protect from severe reactions. Patients with food-induced anaphylaxis need detailed counselling about food allergen sources. Additionally, the differences in the amount of food allergen might not be age but rather depending on the major food allergen in this age group (children - peanut and adults - wheat).

Acknowledgements: Network for Online Registration of Anaphylaxis (NORA) participating centers can be found under www.anaphylaxie.net.

PD08 New digestibility model(s) for investigating allergenicity of proteins

Jaap Akkerdaas1, Muriel Totis2, Annabelle Capt2, Corinne Herouet-Guicheney2, Ronald van Ree1

1Academic Medical Center, Amsterdam, the Netherlands; 2Bayer Crop Science, Valbonne, France

Correspondence: Jaap Akkerdaas - j.h.akkerdaas@amc.uva.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD08

Introduction: Gastric digestion assays have been part of the weight-of-evidence approach for evaluating the allergenic potential of proteins expressed in GM crops since protein stability in such assays was suggested to correlate with the allergenic status of proteins. EFSA has provided guidance that more physiologically relevant digestion assays should be evaluated for their potential to support the allergenicity risk assessment.

Methods: Nine proteins (shrimp and porcine tropomyosin, peanut and green pea albumin, peach and strawberry LTP, fish and bovine collagen, and carp parvalbumin) were subjected to 9 different gastric digestion conditions (pH 1.2/2.5/4.0, with three pepsin/protein ratios [PPR] 10:1/1:1/1:10), followed by duodenal digestion. Samples were taken at different time points and analyzed by SDS-PAGE and immunoblotting (mono-specific polyclonal rabbit antisera).

Results: The idea behind the four protein pairs was to pairwise compare an established strong allergen and a related non-allergen or weak allergen. Originally, we set out to do the same for fish parvalbumins, but purification of the hypothesized weak allergenic version from swordfish/tuna turned out to be extremely difficult due to the low content in the fish muscle (which is probably the more likely explanation of the low allergenicity of these fish). For three of the four pairs (tropomyosins, albumins and LTPs), the allergenic protein presented as the more stable during gastric digestion. The optimal conditions for this were pH1.2 and/or pH2.5 in combination with higher physiological PPRs (10 and/or 1). Gastric digestion at p 4.0 was clearly a less discriminative condition. Surprisingly, in case of the collagens, the allergenic one from fish was more labile than its bovine counterpart. Results from the duodenal digestion showed that, after gastric digestion at pH2.5 and/or 4.0 (less so after pH1.2), all proteins including all established allergens, were completely digested, also if they were resistant to preceding gastric digestion.

Conclusions: Gastric digestion at low (i.e. optimal) pH still remains the more appropriate but not perfect tool to use in building weight of evidence for the risk assessment of novel transgenes for GM crops. More physiological conditions, like higher gastric pH and/or inclusion of duodenal digestion may in fact be misleading with established strong allergens such as Ara h 2, Pru p 3 and Cyp c 1 being readily and completely digested.

PD09 Increased parental anxiety and voluntary allergenic food avoidance (VAFA) in the siblings of the index case (IC) with single or multiple food allergies: exploring the parental response to the interventions for addressing their anxiety and successful introduction of new food

Tushar Banerjee, Antima Banerjee

Darlington Memorial Hospital, Darlington, United Kingdom

Correspondence: Tushar Banerjee - bnrjt07@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD09

Introduction: It is known that parental anxiety & VAFA in siblings of an IC may affect the nutrition and quality of life (QOL). There is no evidence to support investigation and challenge for food allergy in the unaffected siblings. This study explores VAFA, parental anxiety and parental response to possible measures for facilitating new food introduction to the unaffected siblings of an IC.

Methods: The data was obtained from 40 families with proven food allergy in the IC attending a hospital in the UK. The parents were practicing VAFA in the unaffected siblings. The families with siblings suffering from eczema and asthma were excluded from the study. The families were offered 3 options:
  1. 1.

    Continue VAFA

     
  2. 2.

    Introduce suspected food in the hospital restaurant conveniently located near A&E and wait for 2 h

     
  3. 3.

    Give the suspected food at home during the day time.

     
Results: The parental anxiety score (AS) was measured in Likert Scale (0 to 10). Parents of IC with multiple food allergies and strong family history have higher AS to introduce suspected food in the siblings. Peanut, tree nut, milk and fish allergy caused maximum AS. 16 parents with AS >5 requested for allergy test before making the decision. All 16 parents choose to continue VAFA. Additionally, 5 parents in this group preferred VAFA to ensure allergen free household for safety of the IC & 4 witnessed anaphylaxis in the past (Table 1).
Table 1

See text for description

Options

Number of families

Anxiety score 5 to 10

Anxiety score 0 to 5

1. Continue VAFA

16

16

0

2. Introduce food in Hospital Restaurant

20

11

9

3. Introduce food at home

4

0

4

No allergic reaction was noted during food introduction. Parents reported reduction of AS post introduction. Parents felt less hesitant in introducing new food to the siblings in future.

Conclusion: This study highlights the effect of parental anxiety on VAFA. The novel innovative approach of introducing food within the hospital premises restaurant was perceived by parents as less risky and more reassuring. This option positively influenced parental decision to challenge and avoided unnecessary medicalisation of the problem in the unaffected siblings.

PD10 Aggregation of ovalbumin and allergenicity

Mathilde Claude, Grégory Bouchaud, Roberta Lupi, Laure Castan, Olivier Tranquet, Sandra Denery-Papini, Marie Bodinier, Chantal Brossard

INRA UR 1268 Biopolymers Interactions Assemblies, Nantes, France

Correspondence: Mathilde Claude - mathilde.claude@nantes.inra.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD10

Introduction: Allergen structure is often modified when heating foods. Aggregation is an irreversible modification of proteins with the formation of intermolecular bonds between unfolded proteins. Depending on the balance of attractive and repulsive interactions during heating, aggregates of various morphologies may be generated. This study investigates how different way of aggregating ovalbumin modulates its allergenicity by comparing two morphologies of aggregates obtained under opposite electrostatic conditions.

Methods: An ovalbumin solution was extensively heated (80°C for 6 h) under opposite electrostatic conditions to form small linear and large spherical-agglomerated aggregates. In a murine model of allergy, we compared the Ig production when sensitizing mice with the aggregates and the subsequent elicitation phase upon an oral challenge with native ovalbumin. The reactivity of specific IgE in mice sera was characterized by ELISA, Rat Basophil Leukemia assay and pepscan analysis.

Results: IgE production was significantly lower for the small aggregates than for the large aggregates, whereas IgG1 and IgG2a productions didn’t change. In agreement with the IgE production, both symptoms upon oral challenge and basophil degranulation with native ovalbumin were reduced for mice sensitized with small compared to large aggregates. Pepscan analysis revealed two common linear IgE-epitopes but the aggregates were similarly or differently bound and cross-linked depending on the aggregate that had been used during sensitization. These results showed that small aggregates of ovalbumin formed under repulsive electrostatic conditions displayed a lower allergenic potential than the large aggregates. The way ovalbumin aggregated also modified the IgE repertory.

Conclusion: This work illustrates links between food structure and allergenic potential on parameters from the sensitization phase with some consequences on the elicitation phase of the allergic reaction. For the first time, we show that the physicochemical conditions when heating ovalbumin and consequently the aggregated structure are important parameters to consider in the context of allergy.

PD11 Residual determination of milk and egg allergens in bakery products by LC-MS/MS

Rosella De Poi1,2, Elisa Gritti1, Emiliano De Dominicis1, Bert Popping1, Patrizia Polverino de Laureto2

1R&D Department Italy Mérieux NutriSciences, Resana, Italy; 2Department of Pharmaceutical Sciences, Università di Padova, Padova, Italy

Correspondence: Rosella De Poi - rossella.depoi@studenti.unipd.it

Clinical and Translational Allergy 2017, 7(Suppl 1):PD11

Introduction: Food allergy is causing adverse health effects arising from specific immune-mediated responses, occurring reproducibly upon oral exposure to a given food. In the absence of a cure, sufferers have to rely on the accurate labeling of food to avoid allergens. Egg and cow’s milk proteins are common triggers of allergic reactions, especially in children. Following a multimethod comparative study about the latest approaches in food analysis using state-of-the-art technology (see our previous work), one specific goal of this study is to develop and validate a LC-MS/MS method for residual determination of cow’s milk and egg allergens in bakery products.

Methods: After sample homogenization, proteins are extracted, denatured and reduced by TCEP. Free thiol moieties are then alkylated and proteins digested by trypsin. The peptide mixtures obtained are then purified by Solid Phase Extraction and analyzed by LC-MS/MS using Sciex Q-Trap 6500 mass spectrometer. For our purpose, a Multiple Reaction Monitoring (MRM) method specific for milk β-lactoglobulin (β-lg) and egg ovalbumin was set up.

Results: After spiking a mix of β-lg and ovalbumin into different bakery products, specific MRM signals were detected for both proteins. As an example, two XIC graphs for one of the MRM transitions investigated in β-lg are reported below (Fig. 1). The signal is clearly visible in the product spiked with as little as 0,05 mg/kg of β-lg (B), but is absent in the blank (A).
Fig. 1

See text for description

The efficacy of the MRM method was assessed by testing a certified material (cake mix, FAPAS) for milk’s presence. The material was previously used for a ring test involving different ELISA kits. As ELISA kits suffer from high kit-to-kit variability (as can be seen in many proficiency testing results) a quantitative comparison with the results obtained from ELISAs was not possible. In LC-MS/MS analysis, quantification by MRM is generally more accurate as it is not reliant upon biological interactions like antibodies.

Conclusion: The LC-MS/MS approach, combined with an efficient extraction method, shows high sensitivity and selectivity under all evaluated conditions, without producing false negatives for neither egg nor milk. The developed method provides a valid alternative to the ELISA kits on the market, bypassing issues associated with antigen-antibody interactions and retaining a low limit of quantification. The method will be validated and considered for accreditation.

PD12 Predictive value of ovomucoid-specific IgE in the diagnosis of egg allergy in Finnish children

Kati Palosuo, Anna Kaarina Kukkonen, Anna Pelkonen, Mika Mäkelä

Helsinki University Hospital, Skin and Allergy Hospital, University of Helsinki, Helsinki, Finland

Correspondence: Kati Palosuo - kati.palosuo@fimnet.fi

Clinical and Translational Allergy 2017, 7(Suppl 1):PD12

Introduction: To calculate optimal cut-off values for egg white and Gal d 1,2,3, and 4 -specific IgE (sIgE) predicting positive oral challenges in 100 Finnish children with suspected egg allergy.

Methods: 100 patients (age 1–19 years, mean 9.2, median 9.6 years) with suspected egg allergy underwent double-blind, placebo-controlled (n = 60) or open (n = 40) food challenges with heated egg white. Serum IgE levels to egg white as well as the components Gal d 1 (ovomucoid), Gal d 2 (ovalbumin), Gal d 3 (conalbumin) and Gal d 4 (lysozyme) were measured by ImmunoCAP.

Results: Of the 100 challenges 75 were positive. Sensitization to Gal d 1 (ovomucoid) with a cut-off of value of >4.3 kU/L predicted a positive challenge with a specificity of 92% and sensitivity of 83%. The likelihood ratio was 10.3 In ROC analysis the area under curve was 0.92 (95% CI 0.86–0.98). Gal d 1 sIgE levels were significantly higher in the challenge positive (mean 38 kU/L, median 15.8 kU/L) than in the challenge negative group (mean 2.4 kU/L, median 0.5 kU/L), p < 0.0001. The diagnostic capacity of sIgE to egg white and Gal d 2, 3 and 4 was clearly weaker. In ROC analysis the AUC for egg white was 0.88, Gal d 2 0.87, Gal d 3 0.78 and Gal d 4 0.76 (Fig. 2).
Fig. 2

ROC curve. Diagonal segments are produced by ties

Component-specific IgE levels can be useful in predicting outcomes of oral food challenges, but optimal cut-off levels vary in different populations. Sensitization is influenced by many factors including age and geography, whereas challenge outcome is influenced by referral base and challenge procedures. Thus, optimal cut-off levels need to be determined for each population separately. Sensitization to Gal d 1, which is relatively stable against heat and enzymatic digestion, predicts clinical reactivity to both raw and heated egg and is considered a risk factor for persistent egg allergy.

Conclusion: Ovomucoid-specific IgE is useful in distinguishing egg-sensitized patients with clinically reactive egg allergy from those tolerant to heated egg. The optimal cut-off point in a Finnish population of 100 children and adolescents was 4.3 kU/L.

PD13 7S and 11S globulins are likely to be allergens in macadamia nuts

Nanju Alice Lee1, Johanna Rost1, Sridevi Muralidharan1, Dianne Campbell2, Sam Mehr2, Catherine Nock3, Joseph Baumert4, Steve Taylor4

1ARC Training Centre for Advanced Technology in Food Manufacture (ATFM), University of New South Wales, Sydney, Australia; 2Children’s Hospital Westmead, Sydney, Australia; 3Southern Cross University, East Lismore, Australia; 4FARRP, University of Nebraska, Lincoln NE, USA

Correspondence: Nanju Alice Lee - alice.lee@unsw.edu.au

Clinical and Translational Allergy 2017, 7(Suppl 1):PD13

Introduction: Macadamia nut is reported to cause allergic reactions in sensitized individuals, and the prevalence is expected to increase along with the increase in world production and popularity of macadamia nuts as an ingredient in pre-packaged foods. Despite several reports documenting macadamia nut allergies, the eliciting allergens have never been identified due to a lack of genomic and proteomic data on macadamia nut. Identification and characterization of allergenic proteins are crucial for developing effective component-resolved diagnosis and management/treatment strategies.

We aimed to identify putative allergenic proteins in macadamia nut by combining patient IgE recognition with an allergenomics approach.

Methods: Five serum samples were collected from patients with clinical allergy. Immunoreactive proteins were identified by immunoblotting with the patient sera. A label-free shotgun proteomics approach was used to investigate the proteomic profile of macadamia nut. Briefly, the molecular weight distribution of proteins was determined by 1-dimentional and 2-dimensional gel electrophoresis. Following in-gel digestion with trypsin, proteins were subjected to liquid chromatography coupled tandem mass spectrometry.

Results: The label-free shotgun proteomics was used to predict putative macadamia nut allergens for the first time. The amino acid sequence homologies to 21 known allergens across different plant species were identified, which include lupin, latex, peanut, soy and rice allergens. The immunoblotting of the soluble proteins with the serum IgE revealed five reactive protein bands. The mass spectrometry analysis of the IgE-reactive proteins showed matches to Miamp1 protein, Miamp2, vicilin-like protein, 11S-legumin like protein and lactoylglutathione lyase amongst other proteins.

Conclusion:: The seed storage proteins belonging to 11S and 7S proteins are likely to be biologically active allergens in macadamia nuts.

PD14 Pollen-food syndrome among Italian children: molecular endotypes

Carla Mastrorilli1,2,3, Salvatore Tripodi3,4, Carlo Caffarelli1,3, Serena Perna2, Andrea Di Rienzo Businco4, Ifigenia Sfika4, Riccardo Asero5, Arianna Dondi6, Annamaria Bianchi7, Carlotta Povesi Dascola1, Giampaolo Ricci8, Francesca Cipriani8, Nunzia Maiello9, Michele Miraglia del Giudice9, Tullio Frediani10, Simone Frediani10, Francesco Macrì10, Chiara Pistoletti10, Iride Dello Iacono11, Maria Francesca Patria12, Elena Varin13, Diego Peroni14, Pasquale Comberiati14, Loredana Chini15, Viviana Moschese15, Sandra Lucarelli10, Roberto Bernardini16, Giuseppe Pingitore17, Umberto Pelosi18, Roberta Olcese19, Matteo Moretti10, Anastasia Cirisano20, Diego Faggian21, Alessandro Travaglini15, Mario Plebani21, Maria Carmen Verga11,22, Mauro Calvani23, Paolo Giordani24, Paolo Maria Matricardi2,3

1Pediatric Department, Department of Clinical and Experimental Medicine, Azienda Ospedaliera-Universitaria, University of Parma, Parma, Italy; 2Department of Pediatric Pneumology and Immunology, Charité Medical University Berlin, Berlin, Germany; 3The Italian Pediatric Allergy Network (I-PAN); 4Pediatric Department and Pediatric Allergology Unit, Sandro Pertini Hospital, Rome, Italy; 5Allergology Service, San Carlo Clinic, Paderno Dugnano, Milan, Italy; 6Pediatric Unit, Department for Mother and Child, Ramazzini Hospital, Carpi, Italy; 7Pediatric Unit, Mazzoni Hospital, Ascoli Piceno, Italy; 8Pediatric Unit, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy; 9Pediatric Department, Second University, Naples, Italy; 10Pediatric Department, La Sapienza University, Rome, Italy; 11Pediatric Unit, Fatebenefratelli Hospital, Benevento, Italy; 12Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy; 13Pediatric Intermediate Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy; 14Pediatric Section, Department of Life and Reproduction Sciences, University of Verona, Verona, Italy; 15Pediatric Department, Policlinico of Tor Vergata, Tor Vergata University, Rome, Italy; 16Pediatric Unit, San Giuseppe Hospital, Empoli, Italy; 17Pediatric Unit, Grassi Hospital, Rome, Italy; 18Pediatric Unit, Santa Barbara Hospital, Iglesias, Italy; 19Pulmonary Disease and Allergy Unit, G. Gaslini Hospital, Genoa, Italy; 20Pediatric Unit, Crotone, Italy; 21Department of Laboratory Medicine, University of Padua, Padua, Italy; 22ASL Salerno, Salerno, Italy; 23UOC Pediatria, San Camillo Forlanini, Rome, Italy; 24Department of Statistical Sciences, Sapienza University of Rome, Rome, Italy

Correspondence: Carla Mastrorilli - carla.mastrorilli@icloud.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD14

Introduction: Pollen food syndrome (PFS) is heterogeneous with regard to triggers, severity, natural history, comorbidities and response to treatment. Our study aims to classify different endotypes of PFS based on IgE sensitization to panallergens.

Methods: We examined 1271 Italian children (age 4–18 years) with seasonal allergic rhinoconjunctivitis (SAR). Foods triggering PFS were acquired by questionnaire. Skin prick tests were performed with commercial pollen extracts. IgE to panallergens: Phl p 12 (profilin), Bet v 1 (PR-10) and Pru p 3 (nsLTP), were tested by ImmunoCAP FEIA. An unsupervised hierarchical agglomerative clustering method was applied within PFS population.

Results: PFS was observed in 300/1271 children (24%). Cluster analysis identified five PFS endotypes linked to panallergen IgE sensitization: (1) Co-sensitization to ≥2 panallergens (“multi-panallergen PFS”); (2–4) sensitization to either profilin, or nsLTP, or PR-10 (“mono-panallergen PFS”); (5) no sensitization to panallergens (“no-panallergen PFS”). These endotypes showed peculiar characteristics: (1) “multi-panallergen PFS”: severe disease with frequent allergic comorbidities and multiple offending foods; (2) “Profilin PFS”: OAS triggered by Cucurbitaceae; (3) “LTP PFS”: living in Southern Italy, OAS triggered by hazelnut and peanut; (4) “PR-10 PFS”: OAS triggered by Rosaceae; (5) “no-panallergen” PFS: mild disease and OAS triggered by kiwifruit.

Conclusions: In a Mediterranean country characterized by multiple pollen exposures, PFS is a complex and frequent complication of childhood SAR, with five distinct endotypes marked by peculiar profiles of IgE sensitization to panallergens. Prospective studies in cohorts of PFS patients are now required to test whether this novel classification may be useful for diagnostic and therapeutic purposes in the clinical practice.

PD15 Thermal treatment of bovine caseins could increase their sensitising potential

Noe Ontiveros, Francisco Cabrera-Chavez

University of Sinaloa, Culiacan, Mexico

Correspondence: Francisco Cabrera-Chavez - fcabrera@uas.edu.mx

Clinical and Translational Allergy 2017, 7(Suppl 1):PD15

Introduction: To evaluate the digestibility as well as the immunogenic and sensitizing potential of thermally treated bovine caseins (TT caseins).

Methods: Caseins were dry heated for 30 or 60 min at 140°C. Native and TT caseins were digested in simulated gastric fluid pH 1.2 (10 U of pepsin activity/µg of test protein). Samples of 200 µl were removed after incubation at 37°C. The reaction was quenched by addition of 70 µl of 200 mM NaHCO3, pH 11, and 70 µl 5× Laemmli buffer. The zero time points were prepared by quenching the pepsin in the solution before adding the test protein. The samples were subjected to SDS-PAGE electrophoresis using 10–20% polyacrylamide Tris-glycine gels. BALB/c mice (n = 6/group) were sensitized intraperitoneally without adjuvants through the administration of native or TT caseins in 250 µl of PBS. Sensitizations were performed at days 0, 3, 6, 9, 12, and blood was drawn on day 28. Casein-specific IgG and IgE antibodies were evaluated using ELISA.

Results: There was no effect of incubation of caseins in simulated gastric fluid for 60 min in the absence of pepsin. However, caseins, either native or TT caseins, were very unstable in the presence of pepsin, with a marked loss of full length protein after 0.5 min of incubation. Native and TT caseins were both immunogenic and allergenic at the dose tested (0.05 mg/mouse). Casein-specific IgG and IgE titers were higher in the group of mice sensitized with TT caseins for 30 min than the other groups (p < 0.05). There were no differences between the groups sensitized with native caseins and TT caseins for 60 min (p > 0.05). Specific IgE antibodies in sera from mice sensitized with native casein strongly recognized TT caseins and vice versa (p > 0.05). Extensively heated cow’s milk is an alternative to accelerate tolerance acquisition in some milk allergic cases. This is in line with our digestibility results, an indirect parameter of allergenicity, as TT caseins remains as digestible as native caseins. However, there was no reduction of the sensitizing potential of TT caseins. Although this potential was similar between TT caseins for 60 min and native caseins, longer thermal treatments are not suitable for the study because of the loss of protein solubility.

Conclusion: Thermal treatment of caseins alone does not reduce their allergenic potential highlighting that heat-induced interactions between milk proteins and other milk components are required to reduce their allergenic potential.

PD16 The gaps in anaphylaxis diagnosis and management by French physicians

Guillaume Pouessel1,2, Julie Galand1,2, Julien Labreuche3, Etienne Beaudouin4, Jean-Marie Renaudin4, Anne Moneret-Vautrin4, Antoine Deschildre2, the Anaphylaxis Working Group of the French Allergology Society

1Department of Pediatrics, Children’s Hospital, Roubaix, France; 2Division of Pulmonology and Allergology, Department of Pediatrics, Faculty of Medicine and Children’s Hospital, Lille, France; 3Biostatistics Unit, Maison Régionale de la Recherche Clinique, CHRU Lille, Lille, France; 4Department of Allergology, Emile Durkheim Hospital, Epinal, France

Correspondence: Guillaume Pouessel - guillaume.pouessel@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD16

Introduction: Anaphylaxis is still under-recognized and the treatment is often inadequate with underutilization of adrenaline even by medical personnel.

Our aim was to assess physician’s knowledge regarding diagnosis and management of anaphylaxis in children and to identify the reasons for the gaps.

Methods: Physicians were asked to respond a two-part questionnaire during continuing medical education: 1. A clinical scenario-based questionnaire involving a child experiencing a food-induced anaphylaxis with 5 of 9 true/false questions considered as key questions for an optimal management; 2. Demographic data and questions exploring determinants of an appropriate management.

Results: 318 physicians (GPs, 28%; pediatricians, 23%; allergists, 10%; school-mother and child care doctors, 19%; and junior doctors, 20%) were enrolled. They had private (29%), hospital (31%), or both practice (7%) or others (33%).

Part 1: 70% of participants agreed that the scenario was consistent with anaphylaxis but 24% refused because hemodynamic or respiratory disorders were missing; 31% chose to administer first adrenaline intramuscularly and 30% agreed with both diagnosis and treatment with adrenaline; 74% chose to administer first antihistamine and bronchodilators. Only 50% chose to call immediately the emergency number. Nearly a third estimated that a one-hour observation period was enough. Only 19% had all 5 key responses correct.

Part 2: A correct diagnosis was associated with pediatric specialty (p < 10−4) and hospital practice (p = 0.02); the use of adrenaline in the scenario with a correct diagnosis (p < 10−4), pediatric specialty (p < 10−4), a recent continuing medical education on food allergy (p = 0.005) and experience of adrenaline injection in real life (p = 0.02); all the 5 key responses correct with pediatric specialty (p < 10−4) and a recent continuing medical education (p = 0.04). In case of anaphylaxis in a child, 59% of physicians would immediately inject intramuscularly adrenaline, 22% only after calling an emergency physician, 18% only in case of vital disorders, 3% only in the presence of an emergency physician; 5% would refuse to inject adrenaline themselves (never done or feared side effects).

Conclusion: A large proportion of doctors seem to be unaware of the diagnosis criteria and the recent updated EAACI recommendations on anaphylaxis management. Medical specialty and continuing medical education improve anaphylaxis management.

PD18 Relationship between deamidation intensity and allergenicity of acid hydrolysed wheat proteins preparations: from France to Japan

Olivier Tranquet1, Florence Pineau1, Roberta Lupi1, Shinobu Sakai2, Kayoko Matsunaga2, Reiko Teshima2, Colette Larré1, Sandra Denery1

1UR 1268 Biopolymères, Interactions, Assemblages, INRA, Nantes, France; 2National Institute of Health Sciences, Tokyo, Japan

Correspondence: Olivier Tranquet - olivier.tranquet@nantes.inra.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD18

Introduction: Hydrolyzed wheat proteins (HWP) were used as ingredients in food and cosmetics. From the 2000’s severe food allergy to HWP has been reported in individuals elsewhere tolerant to native wheat proteins. Denery et al. demonstrated that deamidation of wheat proteins, a consequence of acid hydrolysis, generate essential neo-epitopes in these particular allergy to wheat [1]. More recently in Japan, an acid-HWP preparation (a-HWP), named GluPearl 19S, elicited severe skin reactions and food allergy in more than 1800 individuals and was likely to contain deamidated gluten proteins [2]. Level of deamidation depends on treatment intensity; a-HWP preparations with either low or high level of deamidation can be found as ingredient [3]. This study aimed at exploring the impact of deamidation level of wheat proteins on the degranulation of basophils sensitized with IgE from patient allergic to a-HWP.

Methods: Impact of the deamidation level of gliadins and a-HWPs upon IgE reactivity of 8 a-HWP allergic patients was determined by ELISA. Impact of deamidation on basophil degranulation was also explored with humanized Rat Basophil Leukemia cells passively sensitized with IgE from patients and subjected to crosslinking with a set of deamidated samples. Finally IgE Repertoire specific to deamidated wheat protein was then explored by inhibition with INRA-DG1, a mouse monoclonal antibody specific for deamidated gliadins.

Results: Intensity of binding of patient IgE onto a-HWP and the degranulation potency were correlated with level of deamidation. Pre-incubation of deamidated gluten with INRA-DG1 mAb inhibited half of its degranulation capacity with patient IgE. These results suggested that the patient IgE repertoire specific for deamidated gluten proteins is likely to be limited to a very few specificities. GluPearl 19S, involved in the Japanese cases, was determined as highly deamidated. It was the most recognized sample among the 5 deamidated glutens tested in this study.

Conclusion: Although differences exist between French and Japanese cases (such as the tolerance of native wheat proteins), this result suggested that Japanese and French cases suffered from the same unconventional allergy to wheat.

References
  1. 1.

    Denery-Papini S, et al. Allergy 2012;67;1023–32.

     
  2. 2.

    Nakamura R, et al. Int Arch Allergy Immunol. 2013;160, 259–64.

     
  3. 3.

    Tranquet O, et al. J Agric Food Chem. 2015;63:5403–9.

     

PD19 Hen’s egg allergen in house and bed dust is significantly increased after hen’s egg consumption

Sebastian Tschirner, Valérie Trendelenburg, Gabriele Schulz, Bodo Niggemann, Kirsten Beyer

Department of Pediatric Pneumonology and Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany

Correspondence: Sebastian Tschirner - sebastian.tschirner@charite.de

Clinical and Translational Allergy 2017, 7(Suppl 1):PD19

Introduction: Cutaneous exposure to food allergens seems to be an important way of sensitization. It has been shown that household consumption of peanut is a risk factor for the development of peanut allergy. Furthermore, peanut protein was found in house dust. Yet there is only little data on other food allergens; therefore, we wanted to investigate whether hen’s egg (HE) protein could be found in domestic areas.

Methods: 8 households were included in the study. All households were asked to consume a meal of scrambled eggs in their habitual eating areas. Before and 48 h after hen’s egg consumption dust samples were collected in the habitual eating areas and from bed sheets, using a special vacuum cleaner device. HE protein was extracted and HE allergen levels were measured with a commercially available ELISA (limit of detection: 0.05 µg/g). Wilcoxon rank test was used to compare HE levels before and after HE consumption.

Results: HE protein was detectable in all 8 households in the habitual eating areas as well as on bed sheets. At baseline, there was a median of 13.05 µg/g HE protein (range 6.5–13.4 µg/g) in the habitual eating area and a median of 12.9 µg/g HE protein (range 2.0–18.4 µg/g) on the bed sheets. 48 h after consumption of scrambled egg significantly increased levels were measured with a median of 214.0 µg/g HE protein (range 17.0–2409.4 µg/g; p < 0.05) for the eating area and a median of 50.3 µg/g HE protein (range 5.9–247.0 µg/g; p < 0.05) in bed sheets. HE allergens were detectable in the house dust of all households not only in dining areas but also in the bed where HE is usually not consumed, indicating a spreading of food allergens. Furthermore, an increase in protein levels measured after consumption of a HE meal was shown. For infants, who spent most time in bed, house dust containing food allergens could be an important risk factor for food sensitization.

Conclusion: HE allergen was found in house and bed dust with high levels following HE consumption, indicating a potential risk factor for the development of HE sensitization. Nevertheless, further research is necessary to proof whether HE allergens in house and bed dust can cause sensitization and whether there is a correlation between allergen levels and the level of sensitization.

PD20 Native gliadins stimulate the local anaphylactic response in Ussing chamber as studied in murine model of wheat allergy

Youcef Bouferkas, Younes Belabbas, Djamel Saidi, Omar Kheroua, Kamel Eddine El Mecherfi

Laboratory of Physiology of Nutrition and Food Safety, Department of Biology, Faculty of Natural and Life Sciences, University of Oran 1 Ahmed Ben Bella, Oran, Algeria

Correspondence: Youcef Bouferkas - youcef35@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD20

Introduction: The objective of this study is to investigate the impact of the native gliadins on the intestinal electrophysiological parameters as studied in murine allergy model.

Methods: Two groups of mice (n = 10 per group) were established: the first group (control) was sensitized with aluminum hydroxide (Alum) diluted in PBS, the second was sensitized with 10 µg of native gliadins adsorbed on alum (NG). Intraperitoneal (IP) sensitizations were performed at days 0, 10, 20 and 30. One week after the last boost, the jejunum fragments were withdrawn and used for histological analysis and the evaluation of the local anaphylactic responses in Ussing chamber by an ex vivo challenge allowing the contact of jejunums with sensitizing antigen and the measurement of electrophysiological parameters (short-circuit current (Isc) (µA/cm2) and conductance (G) (mmho/cm2).

Results: Intraperitoneal injection of native gliadins induced significant increase of the short circuit current (Isc µA/cm2) (P < 0.001) and conductance (G) values (P < 0.05). The histological observations of jejunum fragments of sensitized mice show an alteration in intestinal barrier (villous atrophy, Lymphocytes infiltration) compared to the control group. The Isc increase in sensitized mice is probably due to a secretory response and might well reflect local anaphylactic responses. The increase of conductance indicate that immunization alters the tight junctions and increases the paracellular permeability of the intestinal epithelium [1]. Several published studies show that food allergy in mice is characterized by villous atrophy and goblet cell hyperplasia, as well as infiltration of IgE-positive mast cells [2].

Conclusion: Our results suggest that the native gliadins modify permeability of the intestinal tract in native gliadin mice which confirm the allergenic potential of native gliadins

References
  1. 1.

    Terpend K, Blaton MA, Candalh C, et al. Intestinal barrier function and cow’s milk sensitization in guinea pigs fed milk or fermented milk. J Pedia Gastroenterol Nutr. 1999;28:191–8.

     
  2. 2.

    Grar H, Dib W, El Mecherfi K E, et al. Supplementation with β-carotene or vitamin E protects against increase in anaphylactic response in β-lactoglobulin-sensitized Balb/c mice: Ex vivo study. European Food Research & Technology 2015;241:393–8.

     

PD21 Oral administration of royal jelly at different dose protect against increase in anaphylactic response in β-lactoglobulin sensitized Balb/c mice

Malika Guendouz, Abir Haddi, Omar Kheroua, Djamel Saidi, Hanane Kaddouri

LPNSA, Biology, Faculty of Natural and Life Sciences, University of Oran 1 Ahmed Ben Bella, Oran, Algeria

Correspondence: Malika Guendouz - guendouzmalika@hotmail.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD21

Introduction: The objective of this work is to check if royal jelly could prevent the allergic response and reduce the clinical manifestations of mice to bovine milk proteins.

Methods: Forty female Balb/c mice at 4 weeks and fed with a standard diet were divided into 5 groups. Four groups received orally royal jelly for 7 days at doses of 0 g/kg (positive control), 0.5, and 1.5 g/kg and are then sensitized intraperitoneally with (β-lactoglobulin) β-Lg adsorbed on Alum. Group 5 received no treatment (negative control). At the end of the experiment, in vivo provocation test (observation of clinical signs 30 min after intraperitoneal injection: 1 mg β-Lg/mouse) and ex vivo provocation test in Ussing chamber by contacting the jejunum with the sensitizing antigen and measurement of electrophysiological parameters: short-circuit current (Isc, μA/cm2) were carried out.

Results: Our results show that the majority of mice pretreated with royal jelly dose showed no clinical signs after challenge compared with positive control mice (CL+). A secretory response reflecting local intestinal anaphylaxis was evident in sensitized mice, as indicated by an increase in Isc (p < 0.001). However, no significant changes in the values of the short circuit current (Isc) were observed after β-Lg challenge in mice that received royal jelly at 0.5, 1 and 1.5 g/kg and immunized with β-Lg. Oral administration of royal jelly at different dose prevents the appearance of clinical signs and the development of anaphylactic local. This effect is probably due to the presence of compound having immunomodulatory activity which may reduce T-cell proliferation, Th2 cytokine production, histamine release from mast cells and antibody IgE and IgG production (Vucevic et al. 2007).

Conclusion:

Oral administration of royal jelly decreases the allergic and inflammatory response in mice and can be considered as a preventive strategy against Cow‘s milk allergy (CMA).

Reference
  1. 1.

    Vucevic D, Melliou E, Vasilijic S, Gasic S, Ivanovski P, Chinou I, Colic M (2007) Fatty acids isolated from royal jelly modulate dendritic cell-mediated immune response in vitro. Int Immunopharmacol. 7:1211–20.

     

POSTER DISCUSSION SESSION 2: Management of food allergy • Diagnosis and treatment • Epidemiology • Therapeutic options

PD22 Sting reactions in beekeepers: characteristics and management

Luis Amaral1, Ana Pereira2, Alice Coimbra1

1Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal; 2CINTESIS, Faculdade de Medicina da Universidade do Porto, Porto, Portugal

Correspondence: Luis Amaral - luis.m.amaral@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD22

Introduction: Our objective was to describe what Portuguese beekeepers do after being stung. The secondary aim was to evaluate their knowledge on adrenaline auto-injectors (AAI), bee venom immunotherapy (VIT), and the medical specialty of Immunoallergology.

Methods: Cross-sectional study using a structured questionnaire including beekeepers present in an apiculture meeting. Data on demographic characteristics, number of stings, reaction description and conduct when stung (treatment, admission to ER) were collected. Awareness of AAI, VIT and the medical specialty of Immunoallergology was also questioned.

Results: A total of 114 beekeepers were included; 91 (80%) male with a median (interquartile range, IQR) age of 40 (17) years. The median (IQR) time of beekeeping was 3 (7.3) years. Nighty-nine (87%) were amateur beekeepers. All had been stung in the last 12 months; 45 (40%) had systemic reactions (11 anaphylaxis) and 41 had local reactions, including 22 large local reactions. Only 19 (42%) of those with systemic reactions went to the ER. Nine out of the 11 who had anaphylaxis went to the ER, but only one was treated with adrenaline. On discharge, an AAI was prescribed to one beekeeper, 4 reported to already have AAI and solely 2 were referred to an Allergist. Twenty-five (22%) used alternative treatments on the sting site, namely, metal, lemon or grape, ammonia, alcohol, vinegar and urine. Forty-one (36%) were aware of the existence of AAI, 35 (30%) of VIT and 32 (28%) of the medical specialty of Immunoallergology. Beekeepers with systemic reactions have demonstrated a better knowledge of AAI and VIT, p < 0.01 and p = 0.03, respectively. Awareness of AAI, VIT and Immunoalergology was not significantly different between gender, age and education groups.

Conclusions: This group of Portuguese beekeepers showed insufficient knowledge on proper management of sting reactions. Approximately one fifth used alternative treatments. Adrenaline underuse, underprescription, as well as an inefficient referral to a specialist, was evident in the ER. There is a rise in beekeeping in Portugal and so it is imperative to promote education on the risks, sting prevention measures and correct treatment of stings. The increasing awareness of the medical specialty of Immunoallergology and the existence of bee venom immunotherapy should assure a prompt referral in case of systemic reactions which is crucial in this population.

PD23 Are atopy patch tests useful to identify food sensitisation in eosinophilic esophagitis?

Luis Amaral1, Leonor Carneiro-Leão1, Susana Rodrigues2, Alice Coimbra1

1Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal; 2Serviço de Gastrenterologia, Centro Hospitalar de São João E.P.E, Porto, Portugal

Correspondence: Luis Amaral - luis.m.amaral@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD23

Introduction: Eosinophilic esophagitis (EoE) is an inflammatory disease of the esophagus characterized by symptoms related to esophageal dysfunction, eosinophilic recruitment and infiltration of the esophageal epithelium. A combined mechanism of IgE dependent/cellular mediated hypersensitivity reactions to foods is thought to contribute to disease pathogenesis.

Our aim was to assess food sensitization in EoE patients with atopy patch tests (APT); A secondary aim was to find any relation between the results of APT, skin prick tests (SPT) and/or specific IgE (sIgE) with response to the six-food elimination diet (SFED).

Methods: A longitudinal study of adult patients diagnosed with EoE was carried out. Patch tests were performed with 9 foods: cow’s milk, hen’s egg, wheat, soy, peanut, walnut and hazelnut were applied undiluted, 1/10 dilution and 1 drop of allergen extract; shrimp and cod were applied raw, cooked and 1 drop of allergen extract. The APT were delivered using 8 mm Finn Chambers®. Occlusion time was 48 h and the results were read 20 min and 24 h after removal. Endoscopy results, SPT, sIgE, medical management and patients’ responses were collected.

Results: Twelve patients agreed to participate, 3 were female with a median (interquartile range, IQR) age of 23 (9) years age, 8 with allergic rhinitis and 2 asthma; 8 were sensitized to aeroallergens, 6 to house dust mites and 4 to pollens. Seven patients had positive food SPT and/or sIgE (3 cow’s milk, 2 wheat and 2 LTPs). Ten patients presented clinical and histological improvement with the SFED and in 8 symptoms and eosinophils recurred on food reintroduction (6 with cow’s milk and 3 with wheat). Only 2 patients presented positive APT: 1 to undiluted hazelnut, who was previously sensitized to LTP; and the other to undiluted soy, which was not clinically relevant since the patient frequently eats soy without any immediate symptoms or worsening of EoE.

Conclusions: Standardization on food APT is lacking. In this series, we did not observe any clinical utility for identifying food sensitivity with atopy patch tests in adult patients with Eosinophilic esophagitis.

PD24 How well can hazelnut allergens distinguish between mild and severe hazelnut allergy?

Mareen Datema1, Laurian Jongejan1, Ronald van Ree1, Michael Clausen2, Andre Knulst3, Nikolaos Papadopoulos4, Marek Kowalski5, Frédéric de Blay6, Aeilko Zwinderman1, Jonas Lidholm7, Stefan Vieths8, Karin Hoffman-Sommergruber9, Clare Mills10, Barbara Ballmer-Weber11, Montserrat Fernandez-Rivas12

1Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands; 2Landspitali University Hospital, Reykjavik, Iceland; 3University Medical Center Utrecht, Utrecht, the Netherlands; 4Centre for Paediatrics and Child Health, Institute of Human Development, University of Manchester, Manchester, United Kingdom; 5Medical University of Lodz, Lodz, Poland; 6University Hospital of Strasbourg, Strasbourg, France; 7Phadia AB, Upsala, Sweden; 8Paul-Ehrlich-Insitut, Federal Institute for Vaccines and Biomedicines, Langen, Germany; 9Medical University of Vienna, Vienna, Austria; 10Manchester Institute of Biotechnology, University of Manchester, Manchester, United Kingdom; 11University Hospital Zürich, Zürich, Switzerland; 12Hospital Clinico San Carlos, IdISSC, Madrid, Spain

Correspondence: Mareen Datema - m.r.datema@amc.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD24

Introduction: Component-resolved diagnosis (CRD) has been shown to improve hazelnut allergy diagnosis. Some allergens have been associated with severity of hazelnut allergy, however few studies have reported the classification accuracy of the markers in discriminating between mild and severe subjects, especially in adults.

Our aims were:
  1. 1.

    to analyze the association between sensitization to single hazelnut allergens and clinical symptom severity;

     
  2. 2.

    to evaluate their ability to discriminate between mild and severe hazelnut allergy.

     

Methods: Subjects (n = 731) from 12 European cities reporting reactions to hazelnut (83.6% adults) were included. In all subjects, sensitization against hazelnut extract and in 423/731, IgE against seven single components (rCor a 1, rCor a 2, rCor a 8, nCor a 9. nCor a 11, nCor a 12, rCor a 14) and CCD was measured. Additionally 124/731 underwent a DBPCFC of which 86 were reactive. Symptoms to hazelnut were categorized into mild, moderate and severe symptoms. Associations between sensitization to hazelnut and severity were analyzed using multinomial regression analyses. The discriminative ability of hazelnut allergens was evaluated by Receiving operating curve (ROC) analysis.

Results: Cor a 9 and Cor a 14 were both positively related with severe symptoms (OR 2.89[1.31–6.34] and OR 4.67[1.76–12.37] respectively) and Cor a 11 and Cor a 12 showed a positive trend in severity. Cor a 1 and 2 were negatively associated with severity (OR 0.36 [0.20–0.64]) and 0.50 [0.24–1.04], respectively). ROC analysis showed a poor to moderate ability to discriminate between reported mild and severe hazelnut with AUCs ranging from 0.50–0.62. However, AUCs for Cor a 9, Cor a 11 and Cor a 14 was significantly better in children, the DBPCFC group and using the combination of these allergens (AUC 0.70–0.86). Sensitivities for Cor a 9 and Cor a 14 were low (24%). Around 75% of the severe subjects with confirmed hazelnut allergy was not sensitized to these allergens.

Conclusion: Sensitization to Cor a 9 and Cor a 14 is associated with severity of hazelnut allergy however, the classification power was moderate in our adult dominated population. Unidentified allergens might elicit the severe symptoms but further research is needed to identify these allergens and to confirm their clinical relevance.

PD25 The clinical utility of basophil activation testing in diagnosis of mugwort pollen-associated peach allergy

Shan Deng, Jia Yin

Peking Union Medical College Hospital, Beijing, China

Correspondence: Shan Deng - dengshan2000@126.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD25

Introduction: Our aim was to assess the performance of basophil activation testing (BAT) as a diagnostic marker for mugwort pollen-associated peach allergy.

Methods: Peach allergic (n = 89), peach-sensitized but tolerant (n = 52) and non-peach-sensitized nonallergic (n = 10) patients underwent sIgE to peach and its components. BAT was performed using flow cytometry.

Results: The patients with peach allergy had higher IgE levels for peach and Pru p 3 than peach sensitized population (P < 0.01). By stimulation with peach extract, BAT in peach-allergic patients showed a significant dose-dependent upregulation of CD63 compared with peach sensitized but tolerant and non-peach-sensitized nonallergic patients. While stimulated with Pru p 3, BAT could also discriminate between peach allergy and tolerance. Receiver operating characteristic curves showed basophil reactivity had larger area under the curve than IgE to peach (AUC 0.744, 95% CI 0.550–0.937, P = 0.039) and Pru p 3 (AUC 0.865, 95% CI 0.705–1.000, P = 0.002); while BAT stimulated with Pru p 3 had the largest area at 0.981 and stimulation with peach extract (100 ng/ml) at 0.942. Previous studies concerning pollen-associated food allergy have compared between healthy controls and food allergic patients, without addressing the possible effect of immunologic cross-reactivity on the performances of BAT. In this study, we performed a comparative analysis with peach-sensitized but tolerant patients. BAT stimulated with the major allergen is better than that with the crude allergen extract in discriminating between peach allergy and tolerance.

Conclusion: BAT stimulated with Pru p 3 is superior to other diagnostic tests in diagnosis of mugwort pollen-associated peach allergy.

PD26 Usefulness of serum-levels of histamine, tryptase, Cys-LTs and 9α11β-PGF2 during oral food challenge

Charlotte Eisenmann, Maria Nassiri, Rabea Reinert, Sabine Dölle, Margitta Worm

Department of Dermatology and Allergy, Allergie-Centrum-Charité, Charité-Universiätsmedizin Berlin, Berlin, Germany

Correspondence: Charlotte Eisenmann - charlotte.eisenmann@charite.de

Clinical and Translational Allergy 2017, 7(Suppl 1):PD26

Introduction: Food Allergy (FA) is a common disease and it is estimated prevalence world-wide ranges between 2–10% with an increasing trend. Peanuts and tree nuts are frequent causes of FA and may albeit rare result in fatal reactions. The diagnosis of FA is based on the personal history, in vivo skin-testing (e.g. SPT), in vitro IgE-testing and oral challenges. The double-blind placebo controlled food challenge (DBPCFC) is the gold standard for diagnosing and categorizing FA. DBPCFC’s are time consuming and bear a risk for the patient. Moreover, sometimes the interpretation of test reactions is difficult. The aim of this study was to analyze mast cell mediators like histamine, tryptase, cys-LTs and 9α11β-PGF2 in serum samples from patients who underwent oral food challenges (OFC) and correlate these parameters with the reaction-severity.

Methods: 32 patients from the Allergy-Center with a history of FA to peanuts or tree nuts were recruited. 40 OFCs were performed. Reaction severity was determined by using the grading according to Ring&Messmer. Severe reactions were observed in 23 cases (grade = 2 in 10 patients, grade = 3 in 13 patients). Blood samples were collected before OFC (T1), 5–10 min after the reaction (T2) and 2 h post-onset (T3). Histamine (LDN, Nordhorn, Germany), cys-LTs (LTC4, LTD4, LTE4) and 9α11β-PGF2 (both Cayman Chemical, Ann Arbor, USA) were determined by ELiSA. Tryptase was kindly measured by Thermo Fisher Scientific, Freiburg, Germany.

Results: We observed a significant increase of tryptase, cyc-LTs and 9α11β-PGF2 after food provocation but not histamine in sera from patients with positive OFC. Tryptase levels correlated significantly with the severity of the reaction and a positive tendency of this correlation was also observed for histamine- and 9α11β-PGF2-levels, but not cys-LTs values.

Conclusion: The studied markers differ in their reliability. Histamine does not support evidence for a positive OFC. By contrast, tryptase but also 9α11β-PGF2 (alone or combined) may be used as supportive markers for diagnosing FA. Whether the total increase of the markers helps to predict severity in a given patient will need to be assessed in future studies.

PD27 sIgE Ana o 1, 2 and 3 accurately distinguish tolerant from allergic children sensitised to cashew nuts

Johanna P. M. van der Valk1, Roy Gerth van Wijk1, Yvonne Vergouwe2, Ewout W. Steyerberg2, Marit Reitsma3, Harry J. Wichers3, Huub F. J. Savelkoul4, Berber Vlieg-Boerstra5, Hans de Groot6, Anthony E. J. Dubois7, Nicolette W. de Jong1

1Department of Internal Medicine, Allergology, Erasmus MC, Rotterdam, the Netherlands; 2Center for Medical Decision Making, Department of Public Health, Erasmus MC, Rotterdam, the Netherlands; 3Wageningen UR Food & Biobased Research, Wageningen, the Netherlands; 4Laboratory of Cell Biology and Immunology, Wageningen University, Wageningen, the Netherlands; 5Department of Paediatrics, Onze Lieve Vrouwe Gasthuis (OLVG), Amsterdam, the Netherlands; 6Department of Pediatric Allergology, Diaconessenhuis Voorburg, RdGG, Delft, the Netherlands; 7Department of Pediatric Pulmonology and Pediatric Allergology, University Medical Centre Groningen, GRIAC Research Institute, University of Groningen, Groningen, the Netherlands

Correspondence: Johanna P.M. van der Valk - j.p.m.vandervalk@erasmusmc.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD27

Introduction: The double-blind, placebo-controlled food challenge test (DBPCFC) is the gold standard in cashew nut allergy. This test is costly, time-consuming and not without side effects. Analysis of IgE-reactivity to cashew nut components may reduce the need for food challenge tests.

Methods: In a prospective and multicentre study, children with suspected cashew nut allergy underwent a DBPCFC with cashew nut. Specific IgE to total cashew nut and to the components Ana o 1, 2 and 3 were determined. A skin prick test (SPT) with cashew nut extract was performed. The association between the outcome of the food challenge test and specific IgE to Ana o 1, 2 and 3 was assessed with logistic regression analyses, unadjusted and adjusted for other diagnostic variables. Discriminative ability was quantified with a concordance index (c).

Results: 173 children (103 boys, 60%) with a median age of 9 years were included. 79% had a positive challenge test outcome. A steep rise in the risk of a positive challenge was observed for specific IgE to each individual component Ana o 1, 2 and 3 with estimated risks up to approximately 100%. Specific IgE to Ana o 1, 2 and 3 better distinguished between cashew-allergic and tolerant children (c = 0.87, 0.85 and 0.89 respectively), than specific IgE to cashew nut or SPT (c = 0.76 and 0.83 respectively). In the multivariable models inclusion of sIgE to Ana o 1, 2 or 3 increased the c-index of history and gender from 0.67 to 0.89 maximally, with increases up to 0.92 and 0.93, respectively when also specific IgE to cashew nut or both IgE and SPT were added.

Conclusion: The major cashew nut allergens Ana o 1, 2 and 3 are each individually predictive for the outcome of food challenge tests in cashew-allergic children.

PD28 Non-ionic iodinated contrast media-induced anaphylaxis – Case series

Fabrícia Carolino, Ana Rodolfo, Josefina Cernadas

Serviço de Imunoalergologia, Centro Hospitalar São João, E.P.E., Porto, Portugal

Correspondence: Fabrícia Carolino - fabricia.c@sapo.pt

Clinical and Translational Allergy 2017, 7(Suppl 1):PD28

Introduction: To assess the prevalence and describe the cases of anaphylaxis to iodinated contrast media (ICM), evaluated in our Drug Allergy Unit (DAU) in the last 6 years.

Methods: Retrospective analysis of medical records of patients assessed in our DAU for suspected hypersensitivity reactions (HSR) to ICM between Jan/10 and Dec/15 (n = 54). Skin prick tests (SPT) were performed with potassium iodate (PI), iodopovidone, and a panel of available non-ionic ICM (iohexol, ioversol, iobitridol, iopromide, iomeprol, iodixanol, amidotrizoate, meglumine); intradermal tests (IDT) were also performed with ICM diluted 1/100–1/10, and undiluted (not in all cases).

Results: Eighteen (33.3%) patients presented with anaphylaxis (10 females, median age 65.5 years, interquartile range 43.0–72.0 years). The clinical manifestations were respiratory (n = 15, 83.3%), mucocutaneous (n = 12, 66.7%), cardiovascular (n = 11, 61.1%) and gastrointestinal (n = 5, 27.8%). No fatal outcomes occurred. Suspect ICM were iobitridol (n = 4, 22.2%), iopromide (n = 3, 16.7%), ioversol (n = 2, 11.1%), iomeprol (n = 1, 5.6%), iohexol (n = 1, 5.6%), and unknown in 7 (38.9%) cases. SPT with iodopovidone and PI were all negative. One patient (anaphylactic shock to iopromide) had a positive SPT (iopromide). In IDT, 4 patients had positive test results to ICM at 1/10 (including the suspect): (1) iopromide and iomeprol; (2) ioversol, iobitridol, iodixanol and amidotrizoate; (3) iobitridol and iopromide; (4) iohexol. The patient with anaphylactic shock to iopromide reacted at 1/100. Other 8 patients had positive IDT only to undiluted solution, with at least 1 of the ICM tested (including the suspect); 6 of these patients were tested to other undiluted ICM with negative results. Skin testing with a panel of ICM is recommended by the ENDA group in these patients, not only to confirm the culprit drug but to assess cross-reactivity and find safe alternatives. The ENDA position paper (2013) makes a weak recommendation to avoid undiluted ICM for skin tests as it may be irritative. Six of eight patients with a positive IDT to the undiluted suspected ICM had a negative test to at least two other undiluted ICM.

Conclusion: In this study we report 30% of ICM HSR fulfilling anaphylaxis criteria, and 70% of these patients had a positive diagnostic work-up. The authors raise the question of whether the IDT should routinely be performed including an undiluted solution, since some potentially allergic patients may be missed otherwise.

PD29 Allergy to lipid transfer protein in pediatric population at the third level hospital in Madrid

Dasha Roa-Medellín, Ana Rodriguez-Fernandez, Joaquín Navarro, Vicente Albendiz, María Luisa Baeza, Sonsoles Intente-Herrero

Hospital General Universitario Gregorio Marañón, Madrid, Spain

Correspondence: Dasha Roa-Medellín - dasharoa@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD29

Introduction: Lipid transfer protein (LTP) Syndrome is a primary food allergy with high prevalence in South Europe population. Its clinical characteristics and prevalence are not well established in the paediatric population.

Methods: A retrospective-descriptive study from Jan 2013 to Dec 2015 of children with sensitization to Specific IgE to Pru p 3 and clinical manifestation in a third-level paediatric hospital was conducted. It was aimed to study and compare the clinical patterns of sensitization.

Results: Eighty-three allergic children with sensitization to Pru p 3 were found. Forty-nine male (59%) and thirty-four females: (41%) were assisted. The average age of first reaction: media: 5.3 years +/−3.6 STD. The history of atopic diseases were: rhinitis 39%, asthma 14% with a broad spectrum of pollen sensitization (Grass pollen: 55.4%, Olea 49.3%, plane tree 25%, Cypress 24%, mugwort 21%) and atopic dermatitis: 32%. The first food trigger involved were peach 36.2% (35), peanut 15.2% (14) walnut 12.2% (11), others fruits 11.2% (10), other legumes 9.2% (8) and other nuts 6.2% (5). The most common first clinical manifestation found was: urticarial 44.2% (43), following of oral allergy syndrome: 15.2% (14), anaphylaxis: 14.2% (13) and cutaneous rash: 12.3% (11), The exercise was a cofactor in a 3% of the population and NSAIDs were not involved. All patients were positive skin prick test and high levels of IgE specific levels to pru p3 median; 8.5 (14.58) IQR.

Conclusion: Severe plant food unrelated independent of peach are involved in LTP Syndrome. Grass and olea pollen are the main aeroallergen in our population. Peach and peanut are the main food elicitors. Urticarial symptoms are the most common clinical manifestation.

PD30 Long term impact of cow’s milk allergy on children and their families – A 7-year follow-up

Andrea Mikkelsen1,2, Kirsten Mehlig2, Lauren Lissner2

1Primary Care Research and Development Centre, Gothenburg, Sweden; 2Department of Public Health and Community Medicine, Section of Epidemiology and Social Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

Correspondence: Andrea Mikkelsen - andrea.mikkelsen@vgregion.se

Clinical and Translational Allergy 2017, 7(Suppl 1):PD30

Introduction: Despite outgrown CMA, we have previously found that many families continue to experience nutritional related problems at a six-month follow-up [1]. Some may develop other food allergies or atopic diseases follow ing the atopic march, and some may fail to progress to unrestricted diet.

Our aims were to assess impact on nutrition related issues at a 7 year follow-up in relation to the development of CMA over time.

Methods: Families of children with CMA, who participated in the validation of the Food hypersensitivity famiLy ImPact questionnaire (FLIP), were re-approached 7 years later for follow-up and administered the FLIP.

Results: Of the original families (n = 94), at 7-year follow-up 84% (n = 79) agreed to participate. The children had a mean age 8.5 years (r = −11 years) and n = 30 (38%) were girls. The majority (n = 49.62%) no longer needed to follow a cow’s milk free diet. The remaining children (n = 0) were still following a special diet due to CMA exclusively (n = 7.9%) or in combination with other food allergy (n = 9.11%) and other food allergy excluding CMA (n = 14.18%). Most children were healthy (n = 67) but n = 8 (10%) had developed other atopic diseases or other non-atopic diseases (n = 3). These findings are in line with those from others [2]. A mixed linear model for the FLIP Nutrition subscale across three time points (baseline, 6-month and 7-year follow-up respectively) in relation to allergy status at 7-year follow-up (i.e. outgrown vs. persistent) showed only a marginally significant improvement in nutrition related issues for the group outgrown CMA (p = 0.07) at 7-year follow-up. For the group with persistent CMA there was no difference in the experienced impact. Despite outgrown CMA, n = 13 children in the group outgrown CMA had a restricted consumption of dairy due to fear of reactions (n = 4) or dislike of milk as a drink (n = 6), or both as a drink and when contained in food (n = 3). The latter group were still consuming non-dairy special products.

Conclusions: There is only a small improvement in nutrition related issues despite outgrown CMA at 7-year follow-up. Many families continue to serve a restricted diet despite outgrown CMA. Nutritional counselling should be considered to all families with children with persistent as well as outgrown CMA in order to ensure optimal nutritional intake, development of eating behaviour and progression to unrestricted diet preventing unnecessary limitations in daily life.

Acknowledgements: Financial support: FoU VG-region post-doctoral scholarship.

References
  1. 1.

    Mikkelsen A, et al. Monitoring the impact of cow’s milk allergy on children and their families with the FLIP questionnaire—a six-month follow-up study. Pediatr Allergy Immunol. 2015.

     
  2. 2.

    Spergel JM. Natural history of cow’s milk allergy. J Allergy Clin Immunol. 2013;131(3):813–4.

     

PD31 Perception of allergen exposure risks in US adults with self-reported food allergies

Linda Verrill, Stefano Luccioli

Center for Food Safety and Applied Nutrition, FDA, College Park MD, USA

Correspondence: Stefano Luccioli - stefano.luccioli@fda.hhs.gov

Clinical and Translational Allergy 2017, 7(Suppl 1):PD31

Introduction: Self-reported food allergies (srFA) have increased in US adults over the past decade. Information on how this population perceives allergen exposure risks is lacking. We sought to identify adults with srFA and assess responses to questions about allergen advisory statements and thresholds.

Methods: We analyzed FDA 2016 Food Safety Survey data in 4619 adults to identify survey respondents with srFA, including reported doctor-diagnosed cases (ddFA). Respondents were asked about knowledge of thresholds or reaction risks and about consumption of products with certain advisory statements or trace allergen amounts.

Results: Weighted prevalence of srFA among survey respondents was 13.5% with ddFA representing 8.0%. The most common foods associated with srfA and ddFA were shellfish, milk, fruits, tree nuts, peanuts, wheat, fish and egg. Prior anaphylaxis history was reported in 24.8% of respondents. With regards to allergen exposure risk, only 33.2% of srFA respondents were aware of the concept of threshold levels, yet 59.0% reported belief that a level existed below which allergic reaction would not occur. 43.7, 39.0 and 48.8% of respondents reported having consumed or likely to consume products with advisory statements of “may contain”, “made with same equipment” or “produced in same facility” respectively, and 38.2% of respondents reported that they would consume products with trace amounts of the food allergen if there were assurances that allergen amount would not trigger reaction. No significant differences in responses were noted between srFA respondents with or without ddFA except ddFA respondents were more likely to view trace allergen amounts as posing higher risk for severe reactions. Respondents with prior anaphylaxis, shellfish or fish allergy were more likely to avoid products with one or more advisory statements while those with peanut, tree nut, milk or wheat allergy were more likely to have consumed these products. Survey data of adults with self-reported food allergies reveal different perceptions of thresholds and individual exposure risks. More education on understanding allergen exposure risks is needed for this population.

Conclusion: Survey data suggest that only one third of srFA respondents understand what allergen thresholds represent, yet over 40% report consuming foods with certain advisory statements. Differences in risk perception may depend on having a ddFA, a prior history of anaphylaxis or on type of food allergen.

PD32 Tolerable dose during oral immunotherapy using IFN-gamma for anaphylactic food allergy: desensitisation and tolerance

Geunwoong Noh1, Eun Ha Jang2

1Department of Allergy, Jeju Halla General Hospital, Jeju, Korea Republic; 2Department of Respiratory Medicine, Hanmaeum General Hospital, Jeju, Korea Republic

Correspondence: Geunwoong Noh - admyth@naver.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD32

Introduction: Oral immunotherapy using IFN-gamma (OIT) for anaphylactic IgE-mediated food allergy (AFA) has been done more than 10 years successfully. In this study, a tolerable dose was introduced during tolerance induction with interferon gamma, and its effectiveness and theoretical meaning was evaluated.

Methods: The study population comprised 30 AFA patients. Blood samples were taken for analysis, including complete blood count with differential counts of eosinophils, serum total IgE levels, and specific IgE for allergenic foods. Skin prick tests were conducted with the allergens. Oral food challenges were performed to diagnose AFA. Fifteen patients received OIT, 5 received classic OIT without tolerable dose, 5 received OIT without interferon gamma, and 5 were not treated (controls).

Results: Patients treated with OIT using IFN-gamma became tolerant to the allergenic food with and without introducing tolerable dose. The tolerable dose was introduced successfully in OIT using IFN-gamma. It was meaningless to introduce tolerable dose in OIT without IFN-gamma. Following the introduction of tolerable dose, the systemic reaction to oral intake subsided, but the local skin reaction to contact with the allergenic food persisted. Tolerable dose was successfully introduced during the oral immunotherapy using IFN-gamma. Conventional oral immunotherapy without using IFN-gamma, the concept of tolerable dose is meaningless because the therapeutic dose is the same or less than the tolerable dose. However, using IFN-gamma, therapeutic dose is escalated much more than that without using IFN-gamma. From the successful introduction of tolerable dose, the nature of tolerance induction was unveiled. Also, the exact meaning of desensitization and tolerance is clarified. By introducing tolerable dose, doctor and patient can confirm the progress of getting tolerance.

Conclusion: Introduction of tolerable dose improved the protocol for OTI using interferon gamma for AFA. In food allergy, the concept of tolerance and desensitization is clearly defined. Tolerance is the result of desensitization to allergens. The local skin reaction and systemic reaction to oral intake were dissociated following OIT for AFA.

PD33 Risk-benefit assessment of nutritional immune interventions during early life

Jolanda van Bilsen1, Frieke Kuper1, André Wolterbeek2, Tanja Rouhani Rankouhi1, Lars Verschuren1, Hilde Cnossen1, Prescilla Jeurink3, Johan Garssen4, Léon Knippels4, Jossie Garthoff3, Geert Houben1, Winfried Leeman1

1TNO, Zeist, the Netherlands; 2Triskelion, Zeist, the Netherlands; 3Nutricia Research, Utrecht, the Netherlands; 4Utrecht Institute for Pharmaceutical Sciences, Utrecht, the Netherlands

Correspondence: Jolanda van Bilsen - j.vanbilsen@tno.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD33

Introduction: The immune health status is strongly determined during early life stages. Many immune-related diseases are thought to find their origin in adverse shifts in immune balances during pregnancy or the first 2–3 years of life, including atopic diseases. Therefore, immune health interventions during these stages of life may be most effective in reducing the loss of health, loss of quality of life and costs to society due to immune-related diseases and disorders. Several starting points for immune health interventions have been identified and are being developed into prophylactic or therapeutic approaches, particularly targeted at the early life stages. Unfortunately, there is no consensus on which parameters should be addressed to assess the safety and/or efficacy of the interventions and how all the available data should be interpreted at the end. Hence, it would be extremely helpful to address this issue by developing a pragmatic, flexible and science-based risk-benefit assessment.

Methods: We adapted the risk-benefit approach [1], to develop a framework for risk-benefit assessment of immune health interventions during early life stages. As case studies, we collected all available in vitro/vivo/silico and human data on galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS).

Results: The severity of hazard and beneficial effects observed and the incidence at which such an effect may be considered acceptable, were used to weigh the risk and beneficial effects. Dose response relationships can be converted to 50% effect doses which, combined with the severity of the effect underlying the dose response curve and concurrent acceptable incidence of this effect, can be used for weighing benefit and risk. In the FOS/GOS case study, several prerequisites of (pre-)clinical data were identified. This risk-benefit framework enables us to evaluate all intervention data available and forms the basis to derive the optimal dose levels of intake.

Conclusion: This novel approach enables risk assessors to take the multitude of different types of data available covering toxicity and efficacy studies at early life stages into account, by ranking and weighing all available data. Ultimately, this assessment will help to determine optimal beneficial and safe dose levels of nutritional immune interventions during early life.

Reference
  1. 1.

    Renwick AG, Flynn A, Fletcher RJ, Müller DJG, Tuijtelaars S, Verhagen H. Risk-benefit 726 analysis of micronutrient. Food Chem Toxicol. 2004;42:1903–22.

     

PD34 FABER 244 IgE test in food allergy. Diagnostic accuracy for LTP proteins

Claudia Alessandri1, Maria Antonetta Ciardiello2, Lisa Tuppo2, Ivana Giangrieco2, Danila Zennaro1, Rosetta Ferrara1, Maria Livia Bernardi1, Georg Mitterer3, Chiara Rafaiani1, Michela Ciancamerla1, Maurizio Tamburrini2, Christian Harwanegg3, Adriano Mari1

1Centri Associati di Allergologia Molecolare - CAAM, Rome, Italy; 2Istituto di Bioscienze e Biorisorse, Consiglio Nazionale delle Ricerche, Naples, Italy; 3MacroarrayDx, Vienna, Austria

Correspondence: Adriano Mari - adriano.mari@caam-allergy.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD34

Introduction: FABER 244 is a new in vitro multiplex test for specific IgE detection using 122 molecular allergens and 122 allergenic extracts, coupled to chemically activated nanoparticles. Allergenic preparations, either produced in house or obtained from commercial providers, are individually coupled to nanobeads by means of optimized protocols to achieve maximum test performance.

Aim was to measure the diagnostic accuracy of FABER 244-122-122 01 by comparing with the ImmunoCAP ISAC 112 (TFS, Sweden) in patients allergic to LTP proteins shared by both tests.

Methods: A real life study as been set by analyzing the clinical records, and the FABER and ISAC test results from 94 consecutive patients referred to CAAM from March 2015 to August 2016. Data were extracted from the electronic medical record InterAll. The diagnostic accuracy measurement and test comparison were performed on 3 LTP proteins (Cor a 8, Jug r 3, Pru p 3) adopting the patients’ symptoms as gold standard and MedCalc as software for statistical analysis. ISAC test Limit of Detection (LoD) was set to 0.3 ISU whereas FABER LoD was set to 0.01 FIU. In the overall analysis attention has been put on additional information coming from non-shared LTPs, Tri a 14 and Ara h 9 for ISAC, and Act d 10, Pun g 1, Sola l 6, Tri a 7 k-LTP, Zea m 14 plus peanut and wheat extracts available on FABER.

Results: Both tests appear to be accurate and well aligned to each other for all three analyzed LTP proteins. In terms of sensitivity FABER performs better than ISAC on Cor a 8 (100 vs 73%), same as ISAC on Jug r 3 (100% both) and FABER better than ISAC on Pru p 3 (96 vs 91%). In terms of specificity FABER performs better than ISAC on Cor a 8 (96 vs 94%), same as ISAC on Jug r 3 (96%), whilst ISAC performs better on Pru p 3 (97 vs 92%). IgE detection by ISAC Ara h 9 and Tri a 14 was compensated by the peanut and wheat extracts, whereas info on additional food LTPs could be obtained from the FABER extended panel including 25 extracts from plant-derived foods bearing LTPs.

Conclusions: FABER test is a new in vitro test for specific IgE detection, including molecules and extracts. Considering the food allergen group belonging to the LTP, FABER appears to be accurate and in good agreement with ISAC results. The specific advantage of FABER relies on the chance of testing patients to a broader panel of LTP as well as to a large number of extracts, complementing the results on single allergenic molecules.

PD35 Greater severity of reaction in high versus low fat matrix peanut challenges

M. Eleonore Pettersson1,2, Afke M. M. Schins1,2, Gerard H. Koppelman1,2, Boudewjin J. Kollen3, Anthony E. J. Dubois1,2

1Department of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children’s Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; 2GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; 3Department of General Practice, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands

Correspondence: M. Eleonore Pettersson - m.e.pettersson@umcg.nl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD35

Introduction: Previous studies have shown that the qualities of the matrix containing an allergenic food may impact the severity of reactions during DBPCFCs. The aim of this study was to examine the impact of the matrix fat content during DBPCFCs to peanut and its effect on the severity of the reaction and eliciting dose.

Methods: Data was collected from the food challenge unit database at the University Medical Center Groningen (November 2002–May 2014), where DBPCFCs were performed as part of routine clinical care. All children during this period with a positive DBPCFC to peanut were included in the analysis. The food challenges were included if they were performed with the two most frequently used recipes (n = 11 excluded). The recipes used were peanut in cookies and peanut in gingerbread, with a fat content of 23.9% and 5.9% respectively. In children with multiple DBPCFCs, only the first test was included (n = 37 tests excluded). 14 cases were excluded due to missing data. For the severity of reaction during the DBPCFC a previously published scoring system was used, with a severity index ranging from 0 to 12. The influence of the matrix on the severity of reaction and eliciting dose was analyzed by linear regression analysis, with correction for possible confounders. A variable was considered a confounder if it changed the beta coefficient by more than 10%. The alpha significance level was set at 0.05.

Results: 210 children were included in the analysis, 141 children were challenged with peanut in cookies (high fat) and 69 children with peanut in gingerbread (low fat). Children challenged with peanut in cookies had more severe reactions during the DBPCFC (β = 0.15, 95% CI 1.49–0.06, p = 0.03), compared to children challenged with peanut in gingerbread. However, there was no significant difference in eliciting dose (β = 0.03, 95% CI-31.91-51.11, p = 0.65). These results were not confounded by age, gender, sIgE, severity of the most severe previous accidental reaction, history of atopic dermatitis, asthma or allergic rhinoconjunctivitis.

Conclusion: Children receiving a high fat matrix peanut challenge have more severe reactions than children receiving this test in a low fat matrix. This supports the role of the food matrix as an augmentation factor which may enhance the severity of both diagnostic as well as accidental reactions. It also raises the possibility that matrix effects during oral immunotherapy with peanut could be a cause of adverse events during such treatment.

PD36 The probability of distribution Alfa-gal associated allergy in Ukraine

Svitlana Zubchenko

Danylo Halytsky Lviv National Medical University, Lviv, Ukraine

Correspondence: Svitlana Zubchenko - maruniak.stepan@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD36

Introduction: Annually number of reports about anaphylaxis caused by food products increases. The development of IgE-mediated reactions to food that is well tolerated in the past, now, sometimes is a true diagnostic and therapeutic challenge for the patient and the doctor. An example of such allergies is delayed allergy to red meat that is associated with the formation of IgE antibody to the oligosaccharide galactose-alfa-1,3-galactose (Alfa-gal). During evolution human body formulated the immunological tolerance to Alfa-gal production through IgG. Factor launch IgE-mediated process are tick bites, which linked the spread of geographical features of this type of food allergy (FA). Proved that serious manifestations of anaphylaxis occur in conditions of consumption of fatty meat or large quantities of meat. Determined that Alfa-gal epitope transmitted through the milk that gives grounds to say about later reaction to this product. It is believed that the alternative cause of sensitization to Alfa-gal infection are different types of parasites.

The aim of our study was to determine the probability of distribution associated Alfa-gal allergy among Ukrainian patients.

Results: We conducted a comparative assessment of different components of the ticks saliva, on which was identified allergic reactions to Alfa-gal in the USA (Amblyomma americanum), Australia (Ixodes holocyclus) and Europe (Ixodes ricinus). The same ingredients not found in these types of ticks, but each of them has a specific immunotropic action. In particular, I. ricinus, prevalence of which in Ukraine in recent years increased by 14–18% containing biological substances that intensified alternative pathway of complement activation, Th2-response, inhibited proliferation of B lymphocytes.

Conclusion: Ukraine has a high probability of spreading Alfa-gal associated FA. The arguments are the same: rising prevalence of I. ricinus, Ukrainian traditional consumption of fatty foods and dairy products, high prevalence of parasitic invasions. There is a necessity of component diagnostics Alfa-gal, which today is not performed. In this case the only way to diagnose is carefully collected history.

PD37 Natural history of hen’s egg allergy in early childhood

Sarah Kuntz, Valérie Trendelenburg, Bodo Niggemann, Kirsten Beyer

Department of Pediatric Pneumology and Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany

Correspondence: Sarah Kuntz - sarah.kuntz@charite.de

Clinical and Translational Allergy 2017, 7(Suppl 1):PD37

Introduction: Hen’s egg (HE) allergy is the most common food allergy in early childhood. Although there is a good prognosis, reported data on the development of clinical tolerance vary between studies. The aim of our study was to analyze the natural history of HE allergy among children with challenge proven HE allergy.

Methods: Data of children undergoing double-blind, placebo-controlled food challenge (DBPCFC) in our center were prospectively recorded. Children who had a DBPCFC with raw HE between 01/2010 and 06/2014 were further evaluated. When data on repeated DBPCFC with either raw or baked egg of the children were not available in our data bank, parents were questioned by telephone with a standardized questionnaire whether their child tolerates raw and/or baked HE in their diet.

Results: 110 children with a positive DBPCFC to HE could be included (41 girls and 69 boys with a median age of 1.4 years (0.4 to 9.8 years) at the first DBPCFC with raw HE). After a median period of 34 months (9 to 96 months), 54/110 children (49%) tolerated raw HE (45 had a second DBPCFC to raw HE without reaction, 9 reported complete tolerance in the interview). Of the remaining 56 children without known tolerance to raw HE (still allergic n = 40, unknown n = 12), more than half (54%, n = 30) could tolerate heated HE after a median period of 26 months (20 had a negative DBPCFC to heated HE, 10 reported tolerance to heated HE in the telephone interview). Altogether 29/69 of the boys (42%) developed clinical tolerance to raw HE within a median period of 36 months (9 to 96 months), while 25/41 of the girls (61%) tolerated raw HE already after a median period of 26 months (11 to 66 months). Tolerance development to raw HE in this study was slightly longer than reported from the EuroPrevall birth cohort. This might be explained that re-challenges were not scheduled on yearly basis as in EuroPrevall but on request of the child’s physician.

Conclusion: Around half of the children with challenge proven HE allergy develop tolerance to raw HE within a median period of 3 years and even more to heated HE. Girls seem to have better chances to develop tolerance to HE in a shorter period of time than boys, but larger trials are necessary to confirm these observation.

PD39 Comparing safety profile of boiled egg oral inmunotherapy as an alternative to raw egg

Pablo Mérida, Adriana Machinena, Montserrat Álvaro, Jaime Lozano, Monica Piquer, Carmen Riggioni, Juan Heber Castellanos, Maria Teresa Giner, Rosa Jimenez, Olga Dominguez, Ana Maria Plaza

Department of Pediatric Allergy and Clinical Immunology, Sant Joan de Déu Hospital, University of Barcelona, Barcelona, Spain

Correspondence: Pablo Mérida - p_merida@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD39

Introduction: Improving safety of egg oral immunotherapy (OIT) is a source of concern. Our group has previously published data regarding safety in a protocol to raw egg (RE)-OIT, reporting adverse reactions in 7.6% of doses and adrenaline use in 26%. To evaluate the safety of boiled egg (BE)-OIT in egg allergic children and compare it with previous data on RE-OIT.

Methods: Medical records of children following the protocol from January 2015 to July 2016 were reviewed. Retrospective data were collected for demographics, adverse events at oral food challenge (OFC) and during induction phase. Specific-IgE (s-IgE) and skin prick test (SPT) were expressed with median and range (min-max). Written informed consent was signed. Open OFC with BE was performed, confirming allergy. Anaphylaxis was defined following EAACI position paper criteria.

Results: 21 patients were enrolled, 76.2% boys, median age 9 years (5–15). At OFC: All had adverse reactions and 9/21 presented anaphylaxis. Total IgE 1141 kU/L (97–3814), ovalbumin-sIgE 3.19 kU/L (0–667), ovomucoid-sIgE 4.47 kU/L (0.89–1480), egg white-sIgE 6.6 kU/L (0–1350); ovalbumin SPT 7.9 mm (2.8–14.7), ovomucoid 9.7 mm (4.2–16.9), egg white 10.4 mm (4–15.6). OIT induction phase: 57.1% (12/21) had adverse events: 42.8% gastrointestinal, 28.5% respiratory and 19% cutaneous. 61.9% (13/21) completed induction reaching at least 5.6 gr of BE (700 mg of protein). 3 patients were excluded for not reaching this dose. 1309 doses were administered and 28 reactions occurred (2.14% of OIT doses). 7/18 had anaphylaxis, 2 patients required adrenaline use (10.5%), 5 withdrew during induction phase (4 due to anaphylaxis and 1 for poor adherence). Egg OIT is still an experimental treatment and aims to modify clinical reactivity in persistently egg-allergic children. BE-OIT enhances children’s diet by including baked and various quantities of fully cooked egg thus improving families quality of life. However, complete tolerance to raw-egg is not attempted. Initial parameters at OFC were comparable to previous RE-OIT group. Adverse events are still a source of concern even with the modified BE-protocol.

Conclusions: Gastrointestinal symptoms were the most frequent adverse reactions and anaphylaxis the most common cause of withdrawal. Within similar populations, BE-OIT showed an improvement in safety profile with fewer adverse reactions and less use of adrenaline; proving to be a better OIT alternative for egg allergic children.

Consent to publish: Written informed consent was obtained.

POSTER DISCUSSION SESSION 3: Clinical and experimental aspects • Molecular mechanisms

PD40 Food allergy has no impact on asthma morbidity except if associated to atopic dermatitis

Melanie Cap1, Elodie Drumez2, Stéphanie Lejeune1, Caroline Thumerelle1, Clémence Mordacq1, Véronique Nève3, Antoine Deschildre1

1Pediatric Pulmonology and Allergy Department, Hôpital Jeanne de Flandre, CHU Lille, Lille, France; 2Biostatistics Department, CHU Lille, Lille, France; 3Pediatric Pulmonary Function Testing Unit, Hôpital Jeanne de Flandre, CHU Lille, Lille, France

Correspondence: Antoine Deschildre - antoine.deschildre@chru-lille.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD40

Introduction: Food allergy (FA) is often associated to asthma. We aimed to investigate the impact of FA on asthma control. Exacerbations, maintenance treatment, and lung function were also evaluated.

Methods: Longitudinal prospective study conducted between August 2015 and March 2016. Allergic asthmatic Children, ≥7 years old, with or without confirmed FA, were included during a scheduled visit. Asthma and FA characteristics were recorded. Asthma control was defined according to GINA criteria. Asthma Control Test (ACT) or pediatric-ACT, asthma exacerbation rate, oral corticosteroids courses (OCC), hospitalisations in the previous year, GINA maintenance treatment level and ICS dose, lung function (FEV1, FEV1/FVC, FeNO) were compared between children with FA and those without.

Results: 212 asthmatic children (mean age: 11.5 years), were included; 57 of them had FA (27%) (nuts = 26, peanut = 23, egg = 11, milk = 3, other = 20, multiple FA = 41). History of life threatening asthma was not different between the 2 groups (p = 0.4). History of food anaphylaxis was documented in 39 patients. 31 children (15%) were treated with Omalizumab, 10 of them with FA. Good control was observed in 38 children with FA (67%), and 94 children without FA (61%) (p = 0.42); there was no difference for ACT or pACT score (p = 0.26), exacerbation rate [mean: 1.2 (+/−2.04) if FA vs 2,22 (+/−3.65) if asthma only (p = 0.1)], OCC (p = 0.08), hospitalisations (p = 0.41), GINA treatment level (p = 0.17), ICS dose (p = 0.16). FEV1/FVC (mean: 84% if FA vs 83%; p = 0.12) and FeNO (median: 42 ppb if FA vs 24 ppb (p = 0.55)] were not different. The type of food allergen, the number of FA, the severity of food reaction had no effect on asthma control. The subgroup of patients with “asthma-atopic dermatitis-FA” (A-DA-FA) had a higher number of exacerbations (p = 0.009) and daily ICS (p = 0.017) compared to patients with asthma, FA and no AD. We did not observe that FA was associated to worse asthma control or morbidity as previously reported [1,2]. Regular follow-up in a tertiary care centre may explain the results. However, we observed that children with FA and AD had a more severe asthma than those with FA but no AD.

Conclusion: Our study does not provide evidence for increase asthma morbidity in children with any FA. The association of A-DA-FA characterized a specific phenotype.

References
  1. 1.

    Johnson J, et al. PloS One. 2015;10:e0124675

     
  2. 2.

    Friedlander JL, et al. J Allergy Clin Immunol Pract 2013;1:479–84.

     

PD41 Skin prick test and development of tolerance in children with egg allergy

Carla Mastrorilli, Sonia Ricò, Margherita Varini, Carlotta Povesi Dascola, Carlo Caffarelli

Pediatric Clinic, Department of Clinical and Experimental Medicine, University of Parma, Parma, Italy

Correspondence: Carla Mastrorilli - carla.mastrorilli@icloud.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD41

Introduction: The aim of our study was to examine whether the loss of positive skin prick test (SPT) reactions to egg white or egg yolk predicted the development of spontaneous clinical tolerance in children with egg allergy.

Methods: We recruited children with egg allergy, as positive oral food challenge with egg (OFC) or suggestive history and positive SPT reactions to yolk egg and/or egg white. All children underwent SPTs with egg white and yolk extracts. Children whose SPT results to both egg white and egg yolk became negative during follow-up were included in group 1, those with persistent positive SPT results in group 2. The acquisition of tolerance to hen’s egg was ascertained by open OFC in both groups with escalating doses every 20 min of hard-boiled egg. The adverse reactions were considered immediate when they appeared within 2 h and delayed after 2 h. In case of negative TPO, the egg was administered at home for 4 days, with control of any adverse reactions. In case of unclear symptoms to TPO, it was performed a double-blind test, placebo-controlled trial.

Results: Seventy-five egg-allergic children (44 males), aged 3–78 months, were enrolled. Among them 23 were assigned to group 1 (negative SPT to yolk and egg white) and 52 in group 2 (positive SPT for yolk and/or egg white). In group 1, a child (4.3%) experienced positive OFC, in group 2, 13 children (25%) did not pass OFC (p < 0.03). In all cases manifestations were immediate, most frequently cutaneous (78%). Persistence of positive SPT was significantly associated with allergic symptoms (atopic dermatitis, oculorhinitis, other food allergies). There was no correlation between persistence of positive SPT, age at first or last egg reaction time interval between the last clinical response and OFC, time interval between the first and last SPT performance, type of symptoms. The diagnostic accuracy of SPT showed best results for sensitivity (0.92) and negative predictive value (0.95).

Conclusion: Children with egg allergy are more likely to tolerate the egg in case of negative SPT, compared to subjects with persistently positive SPT. So, loss of positive SPT may be a predictive marker of tolerance and reduce the need for OFC. However, 1 of 23 children with negative SPT had reactions during OFC (4%). Larger population studies are therefore needed to examine possible mild reactions at OFC in case of negative SPT.

PD42 Extensively hydrolyzed casein formula containing lactobacillus rhamnosus GG prevents the occurrence of other allergic manifestations in subjects with cow’s milk allergy: 3-year randomised controlled trial

Rita Nocerino, Linda Cosenza, Antonio Amoroso, Margherita Di Costanzo, Carmen Di Scala, Giorgio Bedogni, Roberto Berni Canani

University of Naples “Federico II”, Naples, Italy

Correspondence: Rita Nocerino - ritanocerino@alice.it

Clinical and Translational Allergy 2017, 7(Suppl 1):PD42

Introduction: Children with cow’s milk allergy (CMA) have an increased risk to develop other allergic manifestations. We performed a randomized controlled trial (RCT) to test whether the early administration of an extensively hydrolyzed casein formula (EHCF) containing L.rhamnosus GG (LGG) can reduce the 3-year incidence of other allergic manifestations in these patients.

Methods: A parallel-arm RCT was performed in children aged 1 to 12 months with IgE-mediated CMA. Patients were allocated to one of two groups of dietary interventions: EHCF (Nutramigen®, Mead Johnson, Evansville, IN, USA) and EHCF+LGG (Nutramigen LGG®, Mead Johnson, Evansville, IN, USA). All subjects were evaluated during a 36 months follow-up. Other allergic manifestations (atopic eczema, allergic urticaria, asthma and oculorhinitis) were diagnosed using standard criteria by pediatricians blinded to group assignment. Tolerance acquisition was evaluated every 12 month by the result of oral challenge.

Results: 220 subjects (147 male, 67%) with a mean (SD) age of 5.7 (3) months were randomized, 110 to EHCF and 110 to EHCF+LGG. Binomial regression using intention-to-treat analysis revealed that the absolute risk difference (ARD) for the occurrence of at least one allergic manifestation over 36 months was −0.22 (95% CI −0.35 to −9%, p < 0.001) for EHCF+LGG vs. EHCF. The ARD for the occurrence of atopic eczema was −0.13 (95% CI −0.25 to −1%, p < 0.05), −0.14 (95% CI −0.25 to −2%, p < 0.001) for allergic urticaria, −0.11 (95% CI −0.22 to 0%, p > 0.05) for asthma, and −0.17 (95% CI −0.29 to −6%, p < 0.01) for oculorhinitis in EHCF+LGG vs. EHCF group. Binomial regression for repeated measures using per-protocol-analysis with Bonferroni’s correction for 3 comparisons (contrasts) revealed that the ARD for the acquisition of cow’s milk tolerance was 0.20 (95% CI 0.05 to 0.35, p < 0.01) at 12 months, 0.24 (95% CI 0.08 to 0.41, p < 0.01 at 24 months and 0.27 at 36 months (95% CI 0.11 to 0.43, p < 0.001) for the EHCF+LGG vs. the EHCF group.

Conclusion: Compared to EHCF, EHCF+LGG reduces the incidence of other allergic manifestations in children with IgE-mediated CMA. Moreover, the use of this hypoallergenic formula increases the rate of tolerance acquisition at 12, 24 and 36 months.

PD43 How common is soya allergy in peanut-allergic children?

Nandinee Patel, Marta Vazquez-Ortiz, Sarah Lindsley, Paul J. Turner

Section of Paediatrics, Imperial College, London, United Kingdom

Correspondence: Nandinee Patel - nandinee7@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD43

Introduction: The prevalence of peanut allergy is around 2% in children. Current guidance from the European Medicines Agency (EMA) requires any medication containing soya-based products (including soya oil) to state that the product is contra-indicated in peanut-allergic individuals, since both are legumes. While clinical allergy to soya in peanut-allergic individuals is considered to be uncommon, only limited published data are available to substantiate this. We therefore sought to determine the rate of soya allergy in children with challenge-proven peanut allergy.

Methods: We performed open food challenges to soya (total 4.0 g protein) in children with peanut allergy proven through double-blind placebo-controlled food challenge (DBPCFC). All challenges were conducted according to PRACTALL consensus criteria. Where a participant experienced any symptoms during the soya challenge, DBPCFC to soya was undertaken to exclude placebo reactors. Local ethical and regulatory approval was granted, and informed consent was obtained. ClinicalTrials.gov Identifier: NCT02149719.

Results: 38 children (median age 13.5 years, range 8–17 years, M:F 1.3:1) with peanut allergy (confirmed by DBPCFC) participated in this study. Over half had a history of previous anaphylaxis to peanut, and 24% developed anaphylaxis during DBPCFC to peanut. Skin prick test to peanut extract ranged from 5 to 22 mm (median 10 mm), with a median peanut-specific IgE of 46 kU/L. SPT to soya extract was negative in 31/38 children; in the remaining 7 children, SPT varied from 2 to 4 mm. 37/38 (97%) tolerated the open challenge to soya; 1 child experienced oral pruritus which was reproduced during DBPCFC—interestingly, this child tolerated an open challenge to unroasted soya protein. One child developed oral symptoms to roasted but not unroasted soya; this child was also sensitised to birch pollen. There was no evidence of systemic soya allergy in this cohort of peanut-allergic children at challenge.

Conclusion: Co-allergy to soya is uncommon in peanut-allergic children. These data suggest that the EMA requirement for labelling of medicines containing low levels of soya as contraindicated in peanut-allergic individuals is unwarranted.

PD44 The beta-phenotype: clinical and serological data of a new low-risk cow’s milk allergy phenotype

Paloma Poza-Guedes, Ruperto González-Pérez, Inmaculada Sánchez-Machín, Victor Matheu-Delgado

Hospital del Tórax, Santa Cruz de Tenerife, Spain

Correspondence: Paloma Poza-Guedes - pozagdes@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD44

Introduction: Cow’s milk (CM) allergy is a rising problem worldwide. Poor prognostic risk factors such as casein sensitization are well described. Nowadays we have not yet clear clinical markers to differentiate in early stages patients with good prognosis. We analyze the clinical characteristics of patients who present only mild gastrointestinal symptoms.

Methods: We selected pediatric patients who refered only mild gastrointestinal symptoms after CM intake in the last 2 years. Skin prick test (SPT) with commercial extracts were performed with whole CM, casein (CAS), alphalactoalbumin (ALA) and betalactoglobulin (BLG). Measurement of total IgE and specific IgE against milk proteins in patients sera were performed (ImmunoCAP, Sweden). Families have been asked about their tolerance with both whole CM and dairy products. All patients performed an open challenge with CM to confirm clinic. Celiac disease and lactose intolerance was ruled out.

Results: From a total of 645 pediatric patients referring food adverse reaction, in 96 patients (4.3 ± 3 y.o.) have been confirmed mild gastrointestinal symptons after CM intake. The most prevalent symptom was abdominal cramps (n = 72), followed by abdominal bloating (47), mild chronic diarrhea (n = 38) or feed refusal (n = 21). A positive SPT to CM was achieved only in 35 patients (36.4%), with positive BLG in only 21 cases. Milk sIgE showed low rates generally, but BLG sIgE seems like the most prominent. It was noted that in a third of cases sIgE to CM was negative and in almost 25% only BLG showed positive sIgE. All patients identify CM such as the triggering food, although almost a third were still tolerating yogurt. Thus in the remaining patients we performed a subsequent open challenge test with yogurt, showing good tolerance nearly 80% of them. Interestingly only after 1 year, more than a half of patients reached whole CM tolerance. The broad dietary restriction in patients with CM allergy involves important limitations in everyday life. The identification of different clinical phenotypes may have relevant implications for the clinical management, and a potential better short-term prognosis.

Conclusion: We describe a new CM allergy phenotype characterized by mild abdominal symptoms and lower CM sIgE, showing BLG sIgE as a key biologic marker in our population. The identification of this syndrome may be clinically relevant in the management and prognosis of CM allergic patients.

PD45 Mechanistic characteristics of peanut allergic children undergoing oral food challenge and oral immunotherapy

Erik Wambre

Benaroya Research Instiute, Seattle WA, USA

Correspondence: Erik Wambre - ewambre@benaroyaresearch.org

Clinical and Translational Allergy 2017, 7(Suppl 1):PD45

Introduction: Peanut OIT can dramatically improve the quality of life for allergic children but the molecular and immunological changes that occur during treatment are poorly understood.

Methods: Whole blood samples were collected pre- and post-oral food challenge to peanut at baseline and at 6 months from 15 peanut allergic patients participating in a double-blind, placebo-controlled, randomized trial of peanut Oral Immunotherapy (POIT). Basophil activation test (BAT) using CD203c expression was performed after stimulation with different concentration of peanut extract. Peanut-reactive CD4+ T cell response were monitored using the CD154-based assay following stimulation with pool of Ara h 1, 2, 3, 6, 8 and 9 peanut component. Sorted peanut-reactive CD4+ T cells were then run on the Fluidigm 96.96 dynamic array chip to assess changes in gene expression.

Results: Positive reactions to the BAT and presence of peanut-reactive effector TH2A cells lacking CD27 expression reflect the status of sensitization to peanut, proved by Oral food challenge. Oral food challenge to peanut drastically increase the frequencies of peanut-reactive CD4+ T cells before POIT but at a lower extent in the active group post treatment. Changes in the frequency, phenotype and molecular signature of peanut reactive T cells are predictive of early clinical responses induced by POIT. Our results also confirmed that allergen-specific TH2 cells exhibit an “exhausted”phenotype and are preferentially targeted by allergen immunotherapy.

Conclusion: These results reveal novel immunological and transcriptional signatures as surrogate markers of successful immunotherapy.

PD46 Development of a food allergy skin sensitisation model in naive Brown Norway rats

Anne-Sofie Ballegaard, Charlotte Madsen, Juliane Gregersen, Katrine Lindholm Bøgh

National Food Institute, Technical University of Denmark, Søborg, Denmark

Correspondence: Katrine Lindholm Bøgh - kalb@food.dtu.dk

Clinical and Translational Allergy 2017, 7(Suppl 1):PD46

Introduction: Allergic sensitisation to foods may occur in infancy without prior oral exposure to the offending food. This has led to the assumption that food allergy sensitisation may occur through alternative routes, such as via the skin. Recently, concerns have been raised regarding the safety of use of cosmetic and personal care products containing hydrolysed wheat proteins. The aim of this study was to develop a skin sensitisation model in naïve Brown Norway (BN) rats.

Methods: A high IgE-responder BN rat strain bred on a gluten-free diet for several generations were used as an animal model and two different products, unmodified gluten and acid hydrolysed gluten were used as model proteins. Rat abdominal skin was shaved, lightly scratched with sandpaper and exposed to one of the products. The animal model was optimised for duration of skin exposure, the amount of product applied as well as for the post-immunisation regime. Skin conditions were evaluated by histology and water evaporation. At different time points sera were collected and analysed for the level, avidity and cross-reactivity of specific antibodies by different ELISAs. The antibody specificity was evaluated by immunoblotting and the functionality was examined by an ear swelling test.

Results: Both products were able to induce a specific immune response and sensitise through the slightly damaged skin without any use of adjuvant. This was evident before any post-immunisations. The sensitisation response depended on the duration of the skin application as well as on the amount of products applied to the skin. Differences in dose-response relationship were seen between products. The results confirm previous studies showing that acid hydrolysis induced new epitopes while maintaining original epitopes. Antibody avidity differed greatly between the products and showed that the shared epitopes induced antibodies with highest avidity. Oral and i.p. post-immunisation induced different outcomes, with a surprisingly higher response after oral compared to i.p. post-immunisations. The aim of the study, developing an animal model for studying food allergy skin sensitisation, was fulfilled. The model was able to detect differences in the induced response between the two products and further indicated homing of skin immune cells to the gut.

Conclusion: In BN rats non-tolerant to gluten, unmodified and acid hydrolysed gluten has sensitising capacity through the skin.

PD47 The nature of wheat gliadins modifies the immune response in a mice model of food allergy

Grégory Bouchaud1, Laure Castan1,2,3,4, Mathilde Claude1,4, Philippe Aubert3,5,7, Michel Neunlist3,5,7, Antoine Magnan2,3,4,6,7, Marie Bodinier1

1INRA, UR1268 BIA, Nantes, France; 2INSERM, UMR1087, Institut du Thorax, Nantes, France; 3CNRS, UMR6291, Nantes, France; 4Université de Nantes, France; 5INSERM UMR913, Institut des Maladies de l’Appareil Digestif (IMAD), Faculté de Médecine, Nantes, France; 6Service de Pneumologie, Institut du Thorax, CHU de Nantes, Nantes, France; 7DHU2020 Médecine Personnalisée des Maladies Chroniques, Nantes, Nantes, France

Correspondence: Grégory Bouchaud - Gregory.bouchaud@nantes.inra.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD47

Introduction: Food allergies result from a complex immune response involving both innate and adaptive immune cells. Major proteins of wheat flour, gliadins, appear as important allergens and have a special role in wheat-dependent exercise-induced anaphylaxis. Allergen characteristics can influence the allergic response. In this context, chemically modified gliadins by industrial processes impact immune mechanisms orchestrating allergic reaction in an undefined manner. Our study investigates immune reaction development during food allergy with gliadins under native, deamidated or hydrolyzed forms.

Methods: Mice were sensitized with native (NG), deamidated (DG) or hydrolyzed gliadin (HG). Subsequently, mice were challenged by oral gavage with the corresponding allergens. Then, organs were collected at different time points and analyzed for immune and physiological parameters such as gastro-intestinal functions, cytokine secretion or allergenspecific IgE.

Results: Preliminary data clearly show an increase of specific IgE and IgG1 level in serum after challenge when mice were sensitized with DG compared with NG and a level comparable to un-sensitized mice with HG. This was accompanied with an increase of intestinal permeability and histological score reflecting intestinal integrity. Moreover, a more pronounced Th2-polarization together with a decrease in regulatory immunosuppressive response was observed in lymph nodes from mice sensitized with DG compared with NG sensitized mice.

Conclusion: Altogether, our data tend to demonstrate that industrial processes such as deamidation or hydrolysis impact food allergenicity through immune modulation and help us to develop tools to define how they can influence this reaction and encourage or decrease allergic reactions.

PD48 Orally administered hydrolysed ovalbumin as an immunotherapeutic agent in a mouse model of egg allergy

Daniel Lozano-Ojalvo, Alba Pablos-Tanarro, Leticia Pérez-Rodríguez, Elena Molina, Rosina López-Fandiño

Instituto de Investigación en Ciencias de la Alimentación (CIAL, CSIC-UAM), Madrid, Spain

Correspondence: Daniel Lozano-Ojalvo - daniel.lozano@csic.es

Clinical and Translational Allergy 2017, 7(Suppl 1):PD48

Introduction: At present, the main treatment for egg allergic patients is based on food avoidance, which poses a risk, since egg is used as an ingredient in a wide range of food products. Oral immunotherapy (OIT) is a promising treatment option, although the use of intact allergens produces frequent side effects. In this respect, egg white protein hydrolyzates are thought to be safer to induce protective mechanisms leading to oral tolerance. The aim of this study was to determine the immunomodulatory effects of pepsin-hydrolyzed ovalbumin (OVA) administered as OIT in a BALB/c model of egg allergy.

Methods: BALB/c mice were orally sensitized during 6 weeks with 5 mg of raw egg white (EW) using cholera toxin as adjuvant. On week 7, mice underwent an immunotherapy protocol with either intact or pepsin-hydrolyzed OVA during 3 weeks and were subsequently challenged with EW. The severity of the anaphylactic response was evaluated (clinical signs and body temperature drop) and serum levels of mMCP-1 were determined by ELISA. Allergen-specific antibodies, IgE and IgG1, were monitored throughout the OIT. The expression of the genes TSLP, IL-33, IL-25, TGF-β and IL-10 was analyzed by RT-qPCR in the small intestine. Furthermore, cytokine responses were measured in allergen-stimulated splenocytes and changes in cellular populations (Th1, Th2 and T reg) were assessed in the mesenteric lymph nodes (MLNs) using flow cytometry.

Results: Mice orally treated with pepsin-hydrolyzed OVA were significantly protected from anaphylactic reactions compared with the groups of untreated mice and mice treated with intact OVA, which showed anaphylactic signs and a marked decrease of body temperature. Similarly, serum levels of mMCP-1 were lower in mice treated with the hydrolyzate. Desensitization of the allergic mice induced by the hydrolyzate was accompanied by a significant reduction in the levels of EW-specific IgE and IgG1. Administration of hydrolyzed OVA also downregulated the intestinal expression of TSLP, IL-33 and IL-25, and led to higher levels of IL-10 expression. However, the group that received intact OVA showed similar expression levels than untreated control mice. Desensitization by pepsin-hydrolyzed OVA was associated with a shift in the Th2 profile, as shown in ex vivo stimulated splenocytes and flow cytometry analysis of T cell subsets in the MLNs.

Conclusion: OIT with pepsin-hydrolyzed OVA desensitizes and prevents allergen-induced anaphylaxis in mice allergic to EW more effectively than the intact protein.

PD49 Long term reduction in food allergy susceptibility in mice by combining breastfeeding-induced tolerance and TGF-β enriched formula after weaning

Akila Rekima1, Patricia Macchiaverni2, Mathilde Turfkruyer1, Sebastien Holvoet3, Lénaïck Dupuis3, Nour Baiz4, Isabella Annesi-Maesano4, Annick Mercenier3, Sophie Nutten3, Valérie Verhasselt1,5

1University of Nice Sophia Antipolis, TIM, EA 6302, Nice, France; 2Institute of Biomedical Sciences - University of São Paulo, São Paulo, Brazil; 3Nestle Research Center, Lausanne, Switzerland; 4Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d’Epidémiologie et de Santé Publique (IPLESP UMRS 1136), Epidemiology of Allergic and Respiratory Diseases Department (EPAR), Medical School Saint-Antoine, Paris, France; 5The International Inflammation “in-FLAME” Network, Worldwide Universities Network

Correspondence: Akila Rekima - akila.rekima@unice.fr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD49

Introduction: Inconsistencies in findings on food allergy prevention by breastfeeding may result from variations in duration of breastfeeding induced protection. Here, we assessed in mice how long food allergy was prevented by breastfeeding induced oral tolerance, and whether oral TGF-β supplementation after weaning would prolong it.

Methods: We first quantified ovalbumin (OVA) and OVA specific immunoglobulins levels (ELISA) in milk from the French EDEN birth cohort. Since OVA specific Ig were found in all milk samples, we assessed whether OVA-immunized mice exposed to OVA during lactation could prevent allergic diarrhea in their 6 and 13-week-old progeny. In some experiments, a supplement of TGF-β enriched formula was given after weaning.

Results: We found that, at 6 weeks, only 17% of symptom scores were ≥ 3 (diarrhea) during the last 3 oral OVA challenges in the group of mice breastfed by mothers immunized to OVA and exposed to OVA during lactation versus 43% in the group of mice breastfed by naïve mothers. However, at 13 weeks, the percentage of diarrhea increased to 28%. Supplementation with TGF-β after weaning allowed maintaining a strong protection from allergic diarrhea in 13-week-old mice breastfed by OVA-exposed mothers (13% of diarrhea only). This prolonged protection was only observed in mice rendered tolerant by breastfeeding and was associated with an improved gut barrier.

Conclusions: In mice, prevention of food allergy by egg antigen exposure through breast milk is of limited duration. Nutritional intervention by TGF-β supplementation after weaning could prolong beneficial effects of breast milk on food allergy.

PD51 Cross-talk between Tregs and NKT cells in children with food allergy

Ines Mrakovcic-Sutic1, Srdan Banac2, Ivana Sutic3, Zdenka Baricev-Novakovic3, Ingrid Sutic4, Valentino Pavisic1

1Department of Physiology and Immunology, Medical Faculty, Rijeka, Croatia; 2Department of Pediatrics, Medical Faculty, Rijeka, Croatia; 3Department of Public Health, Medical Faculty, University of Rijeka, Rijeka, Croatia; 4Medical Faculty, University of Rijeka, Rijeka, Croatia

Correspondence: Ines Mrakovcic-Sutic - ines.mrakovcic.sutic@medri.uniri.hr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD51

Introduction: Understanding the mechanisms how the host recognizes countless foreign antigens and remains unresponsive to self, have opened many questions in the field of immunological tolerance. The most specific marker that distinguishes regulatory from conventional T cells is forkhead box transcription factor (Foxp 3). Predominant cell types that expressed Foxp 3 are CD4+CD25+ and characteristic of subpopulations which are Foxp 3 negative are their regulatory function lacked. Natural Tregs have the possibility to suppress multiple cell types involved in immunity and inflammation by inhibition the proliferation, immunoglobulin production, the blocking of NK and NKT-cell cytotoxicity, as well as, the function and maturation of dendritic cells. It seems that the efficacy of Treg-based therapy depends on the antigen specificity of these regulatory T cells. The most common use of Tregs is described in the prevention of allergic diseases, autoimmunity and in possibility to moderate transplantation tolerance. NKT cells represent a unique sublineage of innate lymphocytes, which share the properties of natural killer cells and conventional T cells. Hypothesis about regulatory network of Tregs and NKT cells was studied by flow cytometry, analyzing the characteristics of human Tregs and NKT cells of patients with food allergy, compared to healthy volunteers.

Methods: A total of 30 children with food allergy were investigated. None of them was taking any systemically administered medications for at least 3 months before testing. Venous blood samples were taken and peripheral blood leukocytes (PBL) were isolated. Phenotype of lymphocytes was analyzed using intracellular and surface immunofluorescence and flow cytometric analysis (FACSCalibur).

Results: Our preliminary study was shown a significant increased in a percentage of regulatory T lymphocytes and NKT cells in peripheral blood of people with described food allergy. Tregs have the ability to suppress allergic immune response. NKT cells perform an important subpopulation of cells which can play both roles: as effectors and as regulatory cells in a wide range of disease settings.

Conclusion: We can talk about the new kind of cells NKT-reg cells, whose monitoring may lead to important early diagnosis and/or prognosis of food allergies.

Acknowledgements: This work was supported by grants from University of Rijeka (13.06.1.1.14 and 13.06.1.1.15).

PD52 PGE2 diminishes basophil activation in patients with food anaphylaxis dependent of nonsteroidal anti-inflammatory drugs

Mariona Pascal1, Rosa Muñoz-Cano1, Teodoríkez Jiménez-Rodríguez2, Daniel Corbacho1, Jordi Roca-Ferrer1, Joan Bartra1

1Hospital Clinic, IDIBAPS-Universitat de Barcelona, Barcelona, Spain; 2Hospital General Universitario de Alicante, Alicante, Spain

Correspondence: Mariona Pascal - mpascal@clinic.ub.es

Clinical and Translational Allergy 2017, 7(Suppl 1):PD52

Introduction: A direct effect of nonsteroidal anti-inflammatory drugs (NSAIDs), but not selective cyclooxygenase (COX)-2 inhibitors, on basophils using a human model of peach lipid transfer protein (Pru p 3) allergy enhanced by NSAIDs has been recently reported. In patients with food dependent exercise induced anaphylaxis, the administration of misoprostol, a prostaglandin (PG) E1 analog, was reported to inhibit the allergic response. We sought to evaluate the effect of PGE2 in an in vitro model of basophils of patients with Pru p 3 allergy enhanced by NSAIDs.

Methods: A basophil activation test, measured as expression of CD63 (Flow2CAST™, Bühlmann Laboratories AG®, Switzerland) is performed strictly following the manufacturer’s procedure. Stimuli used are: Pru p 3 (1.120 ng/mL), anti-IgE, lysine acetylsalicylate (L-ASA; 3.38 mM) and PGE2 (10–4 M) at several concentrations and in combinations.

Results: A BAT to 6 consecutive patients with Pru p 3 allergy enhanced by NSAIDs has been performed. In all of them, we observe the enhancement of basophil activation caused by the L-ASA in combination with the allergen compared to the activation caused by the allergen alone, as previously described by our group. PGE2 not only diminishes the effect of L-ASA on basophil activation (median CD63+ basophils (%) after stimuli Pru p 3+L-ASA vs Pru p 3+L-ASA+PGE2: 60.25 vs 44.60, p = 0.031) but also the activation caused by the antigen alone although not statistically significant (median CD63+ basophils (%) after stimuli Pru p 3 vs Pru p 3+PGE2: 58.2 vs 37.3, p = 0.063). In 4 of these patients the same experiment was done but using anti-IgE instead of Pru p 3 and the same effect of PGE2 was observed (median CD63+ basophils (%) after stimuli anti-IgE+L-ASA vs anti-IgE+L-ASA+PGE2: 83.7 vs 62.3, p = 0.016; anti-IgE vs anti-IgE+PGE2: 76.3 vs 58.2, p > 0.05).

Conclusion: Preliminary results show that PGE2 diminishes basophil activation in vitro in our patients with food anaphylaxis dependent of NSAIDs. Confirmation of this observation is required with a larger cohort of patients.

PD53 Heterogeneity of specific CD4+ T cell responses to peanut allergic components

Erik Wambre

Benaroya Research Institute, Seattle WA, USA

Correspondence: Erik Wambre - ewambre@benaroyaresearch.org

Clinical and Translational Allergy 2017, 7(Suppl 1):PD53

Introduction: We recently described a unique Th2 cell subset specifically involved in all allergy disease (TH2A cell subset). We investigate the cellular and molecular mechanisms behind clinical heterogeneity of peanut allergic responses.

Methods: We combined a CD154-based assay and a single-cell transcriptomes analysis to assess ex vivo and at a single cell level the specific CD4+ T cell responses to each peanut allergic components (Ara h) in adults with or without peanut allergy.

Results: Pathogenic responses (Th2 response) were specifically associated with short life terminally differentiated allergen-specific CD4+ T cells, which dominate in allergic subjects but are absent in non-allergic subjects. Protective responses in non-atopic individuals were associated with peanut-specific TH1/TH17 cell responses. Within the peanut allergic group, we observed inter-individual variations of the specific immune response to each peanut allergic component. No direct linkage between CD4+ T cell response and IgE responses against each individual peanut allergic component.

Conclusions: Ability to identify immunogenicity and type of response elicited by each peanut allergic component appears to be critical to future success in vaccine development against peanut allergy. Understanding the type of cellular response and the role of genetic restriction may allow to target immune response to critical peanut allergen and to uncover the optimal type of cellular immune response necessary for protection.

PD54 The role of enzymes matrix metalloproteinases 2 and 9 in the pathogenesis of food allergies

Ines Mrakovcic-Sutic1, Srdan Banac2, Valentino Pavisic1, Aleksandar Bulog3, Ivana Sutic4, Vladimir Micovic3, Ingrid Sutic5, Zdenka Baricev-Novakovic4

1Department of Physiology and Immunology, Medical Faculty, Rijeka, Croatia; 2Department of Pediatrics, Medical Faculty, Rijeka, Croatia; 3Department of Public Health, Medical Faculty, University of Rijeka, Rijeka, Croatia; 4Department of Family Medicine, Medical Faculty, University of Rijeka, Rijeka, Croatia; 5Medical Faculty, University of Rijeka, Rijeka, Croatia

Correspondence: Ines Mrakovcic-Sutic - ines.mrakovcic.sutic@medri.uniri.hr

Clinical and Translational Allergy 2017, 7(Suppl 1):PD54

Introduction: Interactions between immune and inflammatory responses may play a crucial role in the development and progression of allergic diseases, autoimmune and chronic progressive inflammatory disease. The matrix metalloproteinases (MMPs) play a key role in angiogenesis together with migration and/or invasion of endothelial cells in surrounding stroma and tissues. MMPs are involved in degrading of extracellular matrix (ECM), which consequently lead to facilitate invading of endothelial cells and in the same time stimulate the releasing of extracellular matrix-sequestered proangiogenic factors (ECM-sequestered proangiogenic factors), integrins, adhesion receptors and different growth factors and receptors. The members of the matrix metalloproteinase (MMP) family are involved in angiogenesis and vascular remodeling, consequently leading to the progression of numerous vascular diseases such as atherosclerosis, varicose veins, hypertension, abdominal aortic aneurysm, preeclampsia, etc. The aim of this study was to examine the values of enzyme matrix metalloproteinase-2 and 9 in urine from children with described food allergies.

Methods: We analyzed 30 patients with children with described food allergies. The method of enzyme immunoassay (ELISA) was used to determine enzymes expression of matrix metalloproteinase-2 and 9 (MMP-2 and 9).

Results: The children with described food allergies had a statistically significantly increased level of MMP-2 and 9 in the urine in comparison with healthy volunteers.

Matrix metalloproteinases (MMPs) play a key role in the physiology of connective tissue development, in morphogenesis and in wound healing and their unregulated activity has been implicated in numerous disease processes including arthritis, tumor cell metastasis and atherosclerosis.

Conclusion: Our data has showed a large increase in the enzyme MMP-2 and 9 in the urine of children with described food allergies, which may be an easy marker for the monitoring of the development of food allergies in children.

Acknowledgements: This work was supported by grants from University of Rijeka (13.06.1.1.14 and 13.06.1.1.15).

PD55 Lactobacillus casei and Lactobacillus delbrueckii ssp. Bulgaricus as sources of IgG and IgE-reactive proteins

Lidia Markiewicz, Agata Szymkiewicz, Anna Szyc, Barbara Wróblewska

Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland

Correspondence: Lidia Markiewicz - l.markiewicz@pan.olsztyn.pl

Clinical and Translational Allergy 2017, 7(Suppl 1):PD55

Introduction: Secretion of antibodies belonging to IgG, IgA and IgM class is a natural response of host organism to any protein antigens including those introduced with food. Production of IgE may, however, indicate on sensitivity of the immune system to a particular protein. Bacteria present in food continuously influence the host body interacting with the immune system. Last reports indicate on possible adverse, IgE-dependent reaction of human immune system with proteins from lactic acid bacteria (LAB), namely Lactobacillus casei. The aim of the study was to investigate whether proteins from LAB species commonly used in food industry react with human both IgG and IgE antibodies.

Methods: Whole cell extracts of two LAB strains Lactobacillus delbrueckii subsp. bulgaricus 151 (L151) and Lactobacillus casei LcY (LcY) were a source of proteins. Two pooled human sera were used as a source of human primary antibodies: serum A obtained by pooling seven sera from allergic patients and serum B obtained by pooling sera from ten allergic patients. As a control, a pool of sera from six healthy participants with negative serum parameters for allergy diagnostic tests, with no allergic manifestations and with defined negative family histories of atopy was used. Bacterial proteins were separated (Tricine SDS-PAGE), then transferred onto nitrocellulose membranes. The membranes were probed with human sera (primary antibodies) and then with fluorescently labelled secondary antibodies: goat anti-human IgG antibodies already conjugated with IRDye® 800CW (Li-COR) and mouse monoclonal anti-human IgE antibodies (Sigma) labelled using the IRDye®680RD Protein Labelling Kit (Li-COR). Signal detection was carried out with the Odyssey Infrared Imaging System.

Results: Analyses carried out with pooled serum A showed only one protein fraction (ca. 36 kDa) in LcY strain reacting with both IgG and IgE. With the use of pooled serum B, however, IgG and IgE reactive proteins were detected in both LcY and L151 strain. Differences in profiles of immunoreactive proteins obtained with the examined sera indicated that bacterial proteins are characterized by different immunological determinants with different affinity to human antibodies.

Conclusions: Immunoreactivity of bacterial proteins, which may be in contact with the human immune system, and studies on immunoreactivity of proteins from bacteria used in food production technology and those comprising the human microbiome should be continued.

PD57 Mineral status of infants requiring dietary management of cow’s milk allergy by using an amino acid-based formula

Bryan M. Harvey1, Lucien F. Harthoorn2, A. Wesley Burks3

1Children’s Investigational Research Program, LLC (CHIRP), Bentonville AR, USA; 2Nutricia Research, Nutricia Advanced Medical Nutrition, Utrecht, the Netherlands; 3University of North Carolina, Chapel Hill NC, USA

Correspondence: Lucien F. Harthoorn - lucien.harthoorn@nutricia.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD57

Introduction: Cow’s milk allergy (CMA) is the most common food allergy in infancy. Fundamental to the management of food allergy is complete elimination of the offending proteins. However, due to dietary elimination CMA patients are at risk for inadequate nutritional intake. Management approaches in infants and young children include the use of hypoallergenic formulas that need to be fully tolerated, support normal growth and also assure adequate nutritional status in these patients. Dietary management of CMA with a hypoallergenic amino acid-based formula (AAF) has been proven to be effective and safe. Data on mineral status after dietary management by AAF are however scarce.

Methods: In a prospective, randomized, double-blind controlled study, full term infants with diagnosed CMA received an AAF (n = 110) with or without synbiotics (neutral and acidic oligosaccharides, Bifidobacterium breve M-16 V) for 16 weeks. Primary outcomes were growth and formula tolerance and have been reported previously [1,2]. Mineral status was assessed by analyses of blood samples obtained at baseline and 16 weeks, which included calcium, phosphorus, chloride, sodium, potassium, magnesium and total iron. Total protein, albumin, prealbumin, hemoglobin and ferritin were also determined. Formula intake was recorded through diaries at weeks 0, 4, 8 and 16 during the study.

Results: Average age of infants at inclusion was 4.5 ± 2.4 months (mean ± SD). Median study product intake ranged from 704 ml/day in the first week to 789 ml/day at week 16. At baseline, averages (mean, median) of blood levels of calcium, phosphorus, chloride, sodium, potassium, magnesium and iron were within reference ranges. After 16 weeks on AAF, the averages of all mineral blood levels were again within the specified reference ranges set for the corresponding infant ages. Also the averages of total protein, albumin, prealbumin, hemoglobin and ferritin were within reference ranges. For some minerals, a number of individual values at baseline were below references, i.e. calcium (n = 1), phosphorus (n = 1), chloride (n = 1), and sodium (n = 1), whereas at week 16 none of these minerals had individual values below reference ranges.

Conclusion: This study shows that an AAF with or without synbiotics, which have been reported previously to be equally tolerated and to support normal growth [1,2], are effective in managing an adequate mineral status in CMA infants.

References
  1. 1.

    Harvey BM, Langford JE, Harthoorn LF, Gillman SA, Green TD, Schwartz RH, Burks AW. Effects on growth and tolerance and hypoallergenicity of an amino acid-based formula with synbiotics. Pediatr Res. 2014;75(2):343–51.

     
  2. 2.

    Burks AW, Hathoorn LF, Van Ampting MT, et. al. Synbiotics-supplemented amino acid-based formula supports adequate growth in cow’s milk allergic infants. Pediatr Allergy Immunol. 2015; 26:316–22.

     

POSTER DISCUSSION SESSION 4: Case reports

PD58 Desensitisation of serious milk allergy in adult patient and monitoring with basophil activation test and IgG4

Georgios Rentzos1,2, Anna-Lena Bramstång Björk1, Ulf Bengtsson2

1Section of Allergology, NÄL Hospital, Trollhättan, Sweden; 2Intitute for Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

Correspondence: Georgios Rentzos - grentzos@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD58

Introduction: Serious life-threatening food allergy is still difficult to treat and usually results in a social life with restrictions. Pre-treatment with Anti-IgE has lately been suggested in order to start desensitization for food allergy in some patient cases. The conventional allergy tests though, are not always enough for monitoring the treatment with Anti-IgE and desensitization process. Here, we present a case report of desensitization against serious allergy to milk and monitoring with basophil activation test (BAT) and IgG4.

Case report: A 70-years old female patient with serious allergy to milk, allergic asthma who was previously treated with immunotherapy for allergy to pollen and animal dander, was referred for allergological assessment and for possible treatment with desensitization to milk allergy. The patient reacted previously with anaphylaxis due to ingestion of traces of milk protein, even due to airborne milk protein and with contact urticaria due to milk. In 2015 the patient started pre-treatment with Anti-IgE, in a dose of 450 mg every 2 weeks, and was monitored with BAT before eventually desensitization. Before the treatment with Anti-IgE, BAT with prick-test extract for milk (PT) (Soluprick, ALK) was 1.148 units (U) and with fresh milk 467.29 U. After six months of treatment with Anti-IgE, BAT analysis was found very low, compared to the values before starting pre-treatment with Anti-IgE (BAT with PT-extract for milk at 1.5U and with fresh milk at 1.8 U), indicating a starting point for desensitization against milk allergy. In addition, sIgE tests showed for milk 580 kU/L, IgG4 for casein 1.55 kU/L after six-months of treatment with Anti-IgE and before starting the desensitization. The patient started desensitization with slow build-up by ingesting fresh milk once a week with target of reaching the cumulative dose of 200 ml after 16 weeks. After 12 weeks of desensitization the patient reacted with mild skin redness in the face and neck when she ingested the dose of 50 ml of fresh milk, and therefore the patient started continuous treatment with H1-antagonstist and anti-leucotrienes daily along with Anti-IgE treatment. New BAT analyses with PT-extract and fresh milk was turned out negative after 12 weeks of ongoing desensitization while IgE for milk showed 390 kU/L and IgG4 for casein 2.51 kU/L. The patient reached the dose of 200 ml fresh milk after 16 weeks and continued consuming daily dairy products without any further reactions by now.

Conclusion: In some patients with serious life-threatening food allergy, pre-treatment with Anti-IgE is required and BAT is suggested as monitoring tool for indicating the starting-point for the desensitization process. BAT along with IgG4 may be used in order to monitor successfully the patient’s acquired tolerance for the food allergen during the desensitization and during the follow-up later on, even when Anti-IgE medication would have been suspended.

Consent to publish: The patient has given consent for presentation and publication of the case.

PD60 A novel combination of an IgE mediated adult onset food allergy and a suspected mast cell activation syndrome presenting as anaphylaxis

Colin Barber, Chrystyna Kalicinsky

Department of Internal Medicine, Section of Clinical Immunology and Allergy, University of Manitoba, Winnipeg MB, Canada

Correspondence: Colin Barber - umbarbec@myumanitoba.ca

Clinical and Translational Allergy 2017, 7(Suppl 1):PD60

Introduction: Food allergy is reported to affect approximately 2% of the adult population, with the majority having had onset during childhood. There is an increasing recognition of adult onset food allergy, however these typically are associated with pollen-plant association, and are more often food- dependent, exercise-induced, anaphylaxis (FDEIAn). According to recent consensus statements, mast cell activation syndromes are divided into 3 subtypes: Primary Mast Cell Activation Syndromes (MCAS), Secondary MCAS, and idiopathic MCAS. A mast cell activation disorder requires clinical symptomatology that is in keeping with the disorder, a transient, measurable increase in either serum tryptase or other markers of mast cell mediators and a response to agents that interfere with mast cell mediators. Recent attempts have been made to standardize an approach to suspected mast cell disorders, in order to appropriately classify individuals with evidence of mast cell activation that did not meet diagnostic criteria for systemic mastocytosis.The combination of adult onset food allergy with an underlying mast cell disorder has not been described previously in the literature, and this case report demonstrates the investigation of an elderly gentleman who presented with first onset anaphylaxis due to food ingestion with evidence of a suspected underlying mast cell activation syndrome.

Case report: A 75-year-old male presented to the local emergency department exhibiting symptoms consistent with anaphylaxis. When found by his son in law he was reported to be flushed and unresponsive. On arrival of emergency medical personnel he was found to be hypotensive with blood pressure values of 80/60, hypothermic at 34.7°C orally, and hypoxemic with a sPO2 of 88% by pulse oximetry. He received a 500 cc IV normal saline bolus with EMS. In the emergency department a blood pressure of 71/44 was recorded. He was treated with 3L of IV crystalloid, epinephrine 1:1000 0.3 mg IM once, diphenhydramine 25 mg IV with a second 50 mg IV dose, ranitidine 150 mg IV once, and methylprednisolone 250 mg IV once with improvement. He suffered a type 2 MI related to anaphylaxis associated hypotension that was manifested by tropinemia.

He had no previous history of anaphylaxis, atopy, lymphoproliferative disorder or other neoplasm. His daily medications included aspirin 81 mg daily, and this in addition to his other regular medications were continued post reaction. He did not take additional doses of aspirin, over the counter or herbal products on the day of reaction. There was no family history of atopy. The Allergy and Clinical Immunology Service was contacted by the emergency physician, at which time the food intake history was unclear, and given his profound hypotension at presentation a concern of a MCAS was raised. This is consistent with suggestions to investigate for MCAS in patient’s presenting with anaphylaxis with profound cardiovascular derangement and lacking documented uritcaria, even if likely attributed to an IgE mediated reaction. He was therefore discharged on cetirizine 10 mg daily, prednisone 50 mg orally for five days, diphenhydramine 25–50 mg orally q6 h as needed, and an epinephrine auto-injector. He was subsequently followed in the Adult Allergy and Clinical Immunology outpatient clinic.

Between the anaphylactic episode and his appointment at the Allergy Clinic [approximate time 1 month] he consumed Atlantic cod without reaction. A food history revealed his initial event had developed 3 h following ingestion of a mixed fish and shellfish stew, which he had consumed without reaction on a regular basis. Due to the concern of a potential underlying MCAS and the severity of his initial reaction, it was felt safest to continue H1 receptor antagonist therapy, as such skin prick testing was deferred for use of ImmunoCAP [serum specific IgE (Phadia, Sweden)] for shellfish, finned fish and hymenoptera venom. A serum tryptase was evaluated. He was given an epinephrine auto-injector to be used in the event of subsequent anaphylactic reaction. At follow up his serum specific IgE was high positive for Shrimp at 13.7 kUA/L, and Crab at 7.3 kUA/L, moderately positive for Lobster at 2.9 kUA/L and Clam at 0.9 kUA/L, while testing negative with values <0.35 kUA/L for Salmon, Walleye Pike and Whitefish. A serum tryptase level was 15 ng/ml [with a normal range from 1 to 11.4 ng/ml], an elevation not diagnostic of systemic mastocytosis, but suggestive of a mast cell activation disorder. A creatinine obtained demonstrated a value of 92, corresponding to an eGFR of >60 ml/min, ruling out reduced renal clearance as a cause of accumulation of serum tryptase.

To further evaluate for a potential mast cell disorder, a 24 h urine methylhistamine level was obtained, demonstrating a value of 103 ug/g Cr (normal range 30–200 ug/g Cr). A serum protein electrophoresis demonstrated no evidence of an M protein. He was seen by the Adult Hematology/Oncology Service at CancerCare Manitoba to definitively exclude a diagnosis of systemic mastocytosis, for which a bone marrow biopsy and c-KIT testing were completed. His c-KIT was negative. A bone marrow biopsy demonstrated normal trilineage hematopoiesis with normal differentiation and maturation without definitive morphological evidence of mastocytosis or lymphoma, specifically revealing no large lymphoid aggregates, abnormal plasma cells, or spindle cells suggestive of mastocytosis. Accompanying flow cytometry demonstrated revealed a sample composed of 23% lymphocytes, of which 84% were T cells, 8% NK cells, and there was a CD4/8 ratio of 0.9. Remaining cells were polyclonal B cells without evidence of lymphoma, plasma cell neoplasm, or mastocytosis. Tryptase was consistently elevated at 17 ng /ml on repeat testing.

Given his elevated tryptase, he was maintained indefinitely on cetirizine, and continued to avoid both fish and shellfish, but did require emergency department monitoring following administration of his epinephrine auto injector in January 2015 following ingestion of a perogy, of which the precise constituents were unknown, and development of a diffuse urticarial rash. He was treated with a 3 day course of 50 mg of oral prednisone.

He fulfills the proposed diagnostic criteria for diagnosis of a suspected MCAS based on guidelines published by Valent and colleagues, however we acknowledge the challenge of establishing the diagnosis in the context of a documented IgE mediated food allergy, and he may be best classified as a Secondary MCAS [IgE-dependent disease related].

Conclusions: The combination of food allergy with a mast cell activation syndrome with onset in the elderly population represents a novel combination that is not well described. It is unclear whether the patient in this case had an underlying mast cell disorder that was previously quiescent and was detected only due to his presentation, or whether this was related to a newly acquired population of non-clonal mast cell hyperplasia secondary to an as yet undiscovered or subclinical triggering source such as malignancy, infection, subclinical thrombosis, an underlying autoimmune condition, increased stimulatory cytokines, or increased vasoactive peptides; as all are postulated triggers of mast cell activation.

The increasing prevalence of food allergy worldwide, and the heightened propensity for life threatening anaphylactic reactions in those with underlying mast cell reactivity highlights the importance of an educated, stepwise, evidence -based diagnostic approach to older adults presenting with anaphylaxis. This further supports the importance of a high level of suspicion for clonal mast cell disorders in patient’s presenting with anaphylaxis with profound cardiovascular manifestations and limited cutaneous manifestations. A case such as this emphasizes the importance of an approach with thorough investigation of all potential allergen exposures, including those to which a patient has been exposed on multiple occasions without systemic or local reaction.

It could be theorized that new sensitization to previously tolerated food antigens with resultant anaphylaxis could be associated with underlying mast cell activation disorders in adults without a history of atopy, particularly when presenting with profound hypotension. Further research is needed into the incidence of adult onset IgE mediated food allergies, anaphylaxis, and the rate at which it is associated with underlying mast cell activation, particularly given the association with MCAS and a heightened risk for a more severe anaphylactic reaction.

Consent to publish: The individual described in the above case report has completed and signed a consent form for publication and presentation, currently stored at the Allergy and Immunology clinical offices in the Health Sciences Centre, Winnipeg, Manitoba, Canada. A copy can be made available if required.

PD61 A natural red pigment as a hidden allergen in delayed idiopathic anaphylaxis: carmine-induced food allergy

Christine Breynaert, Lieve Coorevits, Cornelia Jansen, Erna Van Hoeyveld, Kristin Verbeke, Anne-Marie Kochuyt, Rik Schrijvers

University Hospitals Leuven, Leuven, Belgium

Correspondence: Christine Breynaert - christine.breynaert@uzleuven.be

Clinical and Translational Allergy 2017, 7(Suppl 1):PD61

Introduction: Carmine (E120) is a red dye extracted from dried female cochineal arthropods (Dactylopius coccus cacti) commonly used in foods, drugs and cosmetics. Reports of IgE-mediated carmine allergy are limited.

Case report: A 56-year-old female experienced 2 anaphylactic reactions after eating chicken tikka masala and after a croissant with wild berries topping. She showed immediate nausea, vomiting and diarrhea followed by urticarial rash and facial edema several hours later. Afterwards, patient had, with exception of the wild berries topping, the same food again but without complaints. Skin and immunoCAP (Thermofisher-Phadia) testing were negative with all food allergens relevant to the history, including Tri a19 and galactose-alpha-1.3-galactose. Idiopathic anaphylaxis was diagnosed and an adrenalin auto-injector was prescribed. Several months later, after performing an urea breath test for Helicobacter pylori with a Fortimel® energy strawberry (Nutricia) drink, which contains as potential allergens milk, rape seed oil, sunflower seed oil, soy lecithin and carmine acid, patient experienced immediate epigastric pain followed by dyspnea, facial edema and generalized urticaria. Skin testing with Fortimel® energy strawberry was clearly positive (negative in 5 controls) and negative for milk and soy milk. Specific IgE showed positivity for cochineal extract (2.77 kU/L) (retrospective serum analysis one month before: IgE 1.92 kU/L). Flow cytometric analysis of activated peripheral blood basophils (CD63+CD123 +HLA-DR), including a positive control (anti-IgE), a negative control (without allergen), carmine (Sigma-Aldrich) and fast green (E143), showed clear CD63 positivity after stimulation with carmine and not with fast green (Fig. 3). This response was absent in the control patient.
Fig. 3

Basophil activation test

Conclusions: A rare case of carmine-induced food allergy is described and confirmed by sIgE, skin prick test and basophil activation test. Carmine, used as a natural red dye, can cause severe allergic reactions at very low concentrations, with an uncharacteristic time delay between exposure and clinical manifestations, potentially hours later. Unclear episodes of anaphylaxis may be due to sensitization to carmine. Carmine should be included in the allergy work-up of idiopathic (food-induced) anaphylaxis as it can act as a hidden allergen.

Consent to publish: Informed consent of the patient is obtained.

PD62 Oral immunotherapy to wheat in allergic asthmatic female – Case presentation

Diana Deleanu, Adriana Muntean

University of Medicine & Pharmacy Iuliu Hatieganu, Cluj-Napoca, Romania

Correspondence: Diana Deleanu - deleanudiana@yahoo.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD62

Introduction: Immunological adverse reaction to wheat may be either IgE-mediated, either T-cell-dependent. In patients with IgE -mediated allergy to wheat protein there is no specific therapym, except oral immunotherapy (OIT). There are few data regarding OIT with wheat protein in wheat allergic patients.

Case report: A 32 years old female with a history of allergic rhinitis of 12 years developed asthma after 4 years. The patients had a severe persistent rhinitis with a step 4 partially controlled asthma, sensitized to house dust mites and grass pollen. In the last 5 years she developed a severe chronic urticaria, and in the last 2 years her asthma worsened having frequent exacerbations. She was evaluated for the cause of urticaria and of asthma exacerbations. A wheat allergy was confirmed with skin prick test (12 mm diameter), specific IgE (18.6 kUI/l) and a double-blind placebo-controlled food challenge (DBPCFC). An elimination diet was introduced for 2 months. Her urticaria and asthma symptoms improved, but she was unsatisfied with her diet. The patient underwent wheat OIT with cooked pasta. Up-dosing phase started with 1 g pasta in the allergy office and was given at home daily for 6 days. The increasing of the dose was performed weekly in the allergy department, for 8 weeks, by double the quantity up to 120 g. The dose was maintained daily for 6 months. During maintained period, the patients did not have urticaria and asthma exacerbation. She reduced the dose of glucocorticosteroids (nasal and inhaled). At the end of the maintained period, the patient underwent DBPCFC with no symptoms. Specific IgE to wheat decreased to 3.2 kUI/l. She was allowed to eat bread and other foods containing wheat proteins, with no urticaria and no asthma exacerbation, during the 6 months followed up.

Conclusion: A wheat OIT was safe and produced an improvement in allergic rhinitis, asthma and urticaria female patient allergic to wheat. Wheat OIT may induce tolerance to wheat proteins.

Consent to publish: Our patient gave consent for presentation and publication.

PD63 Anaphylaxis to termites’ ingestion in a 30 year-old-woman

Maria Konstantakopoulou, Maria Pasioti, Anastasia Papadopoulou, Anna Iliopoulou, Nikolaos Mikos, Evangelia Kompoti

Allergology Department, Laiko” General Hospital, Athens, Greece

Correspondence: Maria Konstantakopoulou - mariakonstantakopoulou@windowslive.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD63

Introduction: Termites are insects in the Isoptera suborder, Blattodea family, with 3106 described species. They live in worm regions, including Africa, South America, South Europe and Australia. Besides their use as a dietary supplement in non developed regions, they have become popular in western countries as delicacy.

Case report: A 30-year-old Caucasian woman presented at the emergency department with cough, wheezing and urticaria immediately after termites’ ingestion, accompanied by epigastric pain and dizziness 30 min later. It was the first time she consumed termites. The patient had a history of two anaphylactic reactions after honeycomb ingestion. Between the first two episodes she was consuming honey, honeycomb and propolis with no reaction, but subsequently she has banned them. “Slight discomfort” with crustaceans’ consumption was also reported. Skin prick tests to food and aeroallergens were positive to grasses, Bermuda grass, Blatella germ, Derm. Pter., Derm. Far., shrimp, crab and shellfish. Additionally prick to prick tests performed with raw and boiled termites turned out positive contrary to 5 negative controls. Total IgE was slightly elevated and baseline tryptase was normal. Specific IgE antibodies for shrimp, fish, grape, latex, honey bee venom and tropomyosin were negative, unlike Bermuda grass, Blat. germ, Derm. pter. and Derm. far. which were positive.However our patient has neither personal or family history of atopic diseases. According to history and laboratory evaluation, we speculated that the common allergen is a minor panallergen, like a calcium-binding protein, common in pollens (Bermuda) Cyn d 7 but also in crustaceans Cra c 4, cockroach Bla g 6, mite Der f 17 and honey bee (calcium binding protein 39), although, to our knowledge, no cross reactivity between animals and plants has been described. Unfortunately, for lack of means, we couldn’t identify the common allergen. Accidental exposure in related species could also be a reason for sensitization.

Conclusion: This is the first case report of an anaphylactic reaction to termites’ ingestion. It is challenging how the food consumption from different cultures and ambient could increase the appearance of new food allergic reactions.

Consent to publish: Consent was obtained from the patient for publication of this case report.

PD66 Anaphylaxis to banana: a pediatric case report

Ana Rodolfo1, Eunice Dias de Castro1, Borja Bartalomé2, Alice Coimbra1

1Serviço de Imunoalergologia, Centro Hospitalar de São João, E.P.E., Porto, Portugal; 2R&D Department, Bial Aristegui, Bilbao, Spain

Correspondence: Alice Coimbra - aipre@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PD66

Introduction: Food allergy is the most common cause of anaphylaxis in children. Banana is not considered a highly allergenic food and it is usually one of the first fruits introduced in the diet of infants.

Case report: A 2-year-old boy had an anaphylaxis episode immediately after eating a banana. He presented with oral discomfort, facial and tongue angioedema, emesis and rash on his legs. On route to the emergency department, his aunt, an Allergist, gave instructions to administer dimethindene and betamethasone with symptom improvement. He remained in observation at the hospital and an adrenaline auto-injector, antihistamine and oral steroid were prescribed on discharge. He had eaten bananas before, but always in small quantities because he did not like bananas and he would refuse to eat them. He tolerates apple, pear, mango, pineapple, melon, clementine and vegetables. His medical history includes atopic dermatitis and the use of a helmet during six months for the correction of plagio-brachycephaly under the supervision of neurosurgery. Skin prick tests (SPT) with commercial extracts were positive for kiwi and banana; and negative for D. pteronyssinus, grass pollens, Pru p 3 and latex. The skin prick-prick tests with banana were also positive. Total IgE and basal trytpase were normal; specific IgE to banana 2.85 kU/L and negative to latex. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) immunoblotting with banana extract and the patient’s serum was performed and an IgE-binding band with a molecular mass of 20 kDa was detected which suggests sensitization to banana.

Conclusion: Although banana allergy is well established in adults, often associated with latex allergy in the latex-fruit syndrome, there are few case reports of anaphylaxis to banana in children. Banana pulp is rich in thaumatin-like protein (TLP), an allergen with 20 kDa of molecular mass; it is probably the sensitizer in this case. Curiously, SPT with kiwi extract was positive although he never ate kiwi. This may be explained by the cross-reactivity described among the TLPs.

Consent to publish: We hereby declare that the boy’s parents authorized the authors to publish these findings.

PD67 Omalizumab used as treatment in lipid transfer proteins allergy

Kok Loong Ue1, Elizabeth Griffiths1, Stephen Till1,2

1Department of Allergy, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom; 2Department of Allergy, King’s College London, London, United Kingdom

Correspondence: Kok Loong Ue - kokloong.ue@gstt.nhs.uk

Clinical and Translational Allergy 2017, 7(Suppl 1):PD67

Introduction: Omalizumab (anti-IgE antibody) is an effective treatment for asthma and chronic spontaneous urticaria, but relatively few reports exist of use for prevention of uncontrolled systemic allergic reactions in adults. We report the case of an adult patient with allergy to lipid transfer proteins (LTP) who was successfully treated with omalizumab.

Case report: A 34-year-old Caucasian female started to experience anaphylactic reactions to red wine in 2009, with abdominal cramps, vomiting, urticaria, lips and tongue angioedema. She subsequently experienced pharyngeal discomfort with difficulty in breathing after eating grapes. Over the next 3 years she progressed to similar reactions after eating numerous fruits and vegetables. We first became involved in her case in 2012. She underwent investigation with skin tests to a wide range of fruits/vegetables, component and ISAC testing. A diagnosis of LTP allergy was made. She was provided with an anaphylaxis management plan. She continued to have recurrent and frequent reactions despite extensive dietitian input and then antihistamine prophylaxis, with repeated use of adrenaline injector and emergency department attendances. Her dietary intake became heavily restricted and quality of life was significantly affected, both as a result of allergic reactions but further compounded by new depressive and anxiety symptoms. A decision was made to undertake a trial of subcutaneous omalizumab therapy. She underwent a positive baseline double blinded placebo controlled food challenge (DBPCFC) with raisin, developing nasal congestion and abdominal pain that was reproduced when re-challenged with the same dose (20 mg) but not placebo. Treatment was then initiated with omalizumab (300 mg once monthly), in accordance with the asthma dosage recommendation for weight and total IgE. The DBPCFC was repeated after 6 months of omalizumab and a final dose of 600 mg of raisins was fully tolerated. She has subsequently undergone multiple open oral food challenges to previous trigger foods, which have now been reintroduced into her diet. She continues to receive regular omalizumab and has not experienced a recurrence of systemic allergic reactions.

Conclusions: There is currently little data to confirm omalizumab use in patients with anaphylaxis to foods outside of the oral immunotherapy setting. To our knowledge this is the first reported case of omalizumab being used to successfully manage systemic allergic reactions to LTP.

Consent to publish: Written informed consent was obtained from the patient for publication of this abstract and any accompanying images.

PD68 Risk factors for egg allergy in Europe: EuroPrevall birth cohort

Kate Grimshaw1, Graham Roberts1,2,3, Anna Selby1, Indre Butiene4, Jose Ignacio Larco5, Michael Clausen6, Ruta Dubakiene7, Ana Fiandor5, Alessandro Fiocchi8, Linus Grabenhenrich9, Nikos Papadopoulos10,11, Sigurveig Sigurdardottir12, Aline Sprikkelman13, Anne-Fleur Schoemaker13, Marek Kowalski14, Paraskevi Xepapadaki10, Thomas Keil9, Claire Mills15, Kirsten Beyer16

1Experimental Sciences & Human Development in Health Academic Units, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; 2National Institute for Health Research Respiratory Biomedical Research Unit, Southampton, United Kingdom; 3David Hide Asthma and Allergy Research Centre, St Mary’s Hospital, Newport, Isle of Wight, United Kingdom; 4Faculty of Health Sciences, Klaipeda University, Klaipeda, Lithuania; 5La Paz Institute for Health Research, Madrid, Spain; 6Children’s Hospital, Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland; 7Faculty of Medicine, Vilnius University, Vilnius, Lithuania; 8Division of Allergy, Pediatric Hospital Bambino Jesu, Rome, Italy; 9Institute of Social Medicine, Epidemiology and Health Economics, Charité Universitätsmedizin Berlin, Berlin, Germany; 10Allergy Unit, 2nd Pediatric Clinic, University of Athens, Athens, Greece; 11Centre for Paediatrics and Child Health, Institute of Human Development, University of Manchester, Manchester, United Kingdom; 12Department of Immunology, Landspitali – The National University Hospital of Iceland, Reykjavik, Iceland; 13Department of Pediatric Respiratory Medicine and Allergy, Emma Children’s Hospital, Academic Medical Center Amsterdam, Amsterdam, the Netherlands; 14Department of Immunology, Rheumatology and Allergy, Medical University of Lodz, Lodz, Poland; 15Institute of Inflammation and Repair, Manchester Academic Health Science Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, United Kingdom; 16Department of Paediatric Pneumonology and Immunology, Charité Universitätsmedizin Berlin, Berlin, Germany

Correspondence: Graham Roberts - g.c.roberts@soton.ac.uk

Clinical and Translational Allergy 2017, 7(Suppl 1):PD68

Introduction: Hen’s egg is the second most common allergen with a mean incidence of allergy of 1.23% (95% CI 1.27–3.47) in the EuroPrevall birth cohort. There are little data on the risk factors for egg allergy. In this study we aimed to assess the risk factors for egg allergy in the Europrevall birth cohort with a particular focus on eczema.

Methods: The EuroPrevall birth cohort was established across nine European countries and children were followed up to 2 years. Questionnaires were undertaken at 12 and 24 months. Children with suspected egg allergy were invited for skin prick testing, measurement of specific IgE and double-blind, placebo-controlled challenge (DBPCFC) to hen’s egg if allergy was suspected. Each egg allergy case (positive DBPCFC or egg induced anaphylaxis) was allocated two age-matched controls. Statistical analysis was undertaken in SPSS version 22 (IBM, New York, USA) and STATA SE 13 (StataCorp, College Station, USA).

Results: 12,049 infants were recruited into the EuroPrevall birth cohort and 9336 (77.5%) were followed until 2 years. 86 infants had egg allergy (98% via DBPCFC) and were matched with 140 controls. Cases were evaluated at a mean age of 11 months. Infants with egg allergy were significantly more likely to have eczema than controls (76 vs 39%, p < 0.001). Cases were significantly more likely to report rhinitis (26 vs 9%, p < 0.001), to have mould in their home (15.5 vs 6.5%, p = 0.038) and to have received any skin cream, lotion or powder (87.2 vs 70.9%, p = 0.001); they were less likely to be Caucasian (83 vs 93%, p = 0.027). Factors that were independently associated with egg allergy in this analysis were current eczema (adjusted OR 24.08, 95% CI 7.41–78.22), current rhinitis (2.68, 1.02–7.04), antibiotics in the first week of life (7.71, 2.15–27.64) and male gender (2.44, 1.16–5.26). Increasing eczema severity was associated with an increasing risk of egg allergy and eczema was reported to have started an average (SE) of 3.6 (0.5) months before egg allergy was evaluated.

Conclusions: Eczema, rhinitis, antibiotics in the first week of life and male gender are the key risk factors for developing egg allergy. The onset of eczema is temporarily related to developing egg allergy with infants with more severe eczema being more likely to develop egg allergy. This provides potential preventative strategies for egg allergy.

POSTER SESSION 1: Clinical and therapeutic aspects • Diagnosis and treatment • Epidemiology

PP001 Registration of allergies in primary health care history

Zizi Cojocariu, Beatriz Secades Barbado, Vasti Iancu, Esozia Arroabarren, Marta Goñi Esarte, Miren Arteaga

Complejo Hospitalario de Navarra, Navarra, Spain

Correspondence: Zizi Cojocariu - zizicojocariu@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP001

Introduction: The prevalence of the allergologic diseases (AD) is increasing, being an important health problem. WHO classifies the AD between the first 6 pathologies in the world. These, restrict the daily activities of the patient, their life quality and it have a high social and economic impact. Also of the correct diagnose and treatment of the AD, it’s important to do an adequate record in the patient’s history being the mistakes at this level can cause mistakes relates with drug prescription and increase the costs.

Methods: The aim is to evaluate the quality of the computerized record of the allergies in the medical clinic history by the physicians in the health centers of Pamplona, reviewing the clinic history of the patients and by random selection, choose 1 patient of 4, between 15/02/2016 and 14/04/2016.

Results: Have been analyzed 1408 medical histories. Of these, 275 (19.5%) had no record of allergies. In 1133 (80.4%) it had a specific record of allergies, 824 (72.7%) without known allergies. In 309 patients have had recorded allergies and/or secondary effects (Fig. 4).In the analysis of the histories with positive data, in 142 (45.9%) it was diagnosed with a specific allergy (allergologic report or suggestive clinical data) and 167 (54.1%) had diagnosed with secondary known effects or they were registered improperly (recorded without any documents that support it). In these 167 medical histories, 289 records were documented (1.7 average/patient), clinical histories with more than one improperly registration, not mandatorily related between them. Among the wrong registered records (without documents, side known effects or intolerance), 69 (49.6%) were antibiotics, 36 (25.9%) NSAIDs, 34 (24.4%) other allergens (Fig. 5).
Fig. 4

Total allergies registration

Fig. 5

Total allergies registration

Given the clinical, social and economical importance it is a significant fact that 19.5% of the clinical histories revised there is no sign of allergy. In the ones that’s is registered, almost half of them have their record incomplete or insufficient, being the most frequent the antibiotics and NSAIDs, which condition the prescription and it can lead to a rise of the costs, having to use alternative drugs.

Conclusion: The interest of the physicians by allergies it seems is not the expected; a proper register of the allergies/intolerances, as well as a allergologic diagnose when it is indicated, it is fundamental for a good medical practice, quality of the prescription, higher security for the patient and decrease the costs.

PP002 Food allergens sensitisation in atopic asthmatic patients

Mayra Coutinho Andrade, Denise Borges, Jorge Kalil, Pedro Giavina Bianchi, Rosana Camara Agondi

Serviço de Imunologia Clínica e Alergia, Hospital das Clínicas, Universidade São Paulo, São Paolo, Brazil

Correspondence: Mayra Coutinho Andrade - maycoutinho@hotmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP002

Introduction: Sensitization to food allergens in patients with persistent allergic asthma followed in a tertiary clinic center.

Methods: A cross-sectional study was conducted with asthma patients in a regular follow-up in a tertiary clinic in São Paulo, Brazil. The study included patients older than 18 years with allergic asthma, with or without suggestive history of food allergy. Sensitization to aeroallergens, and food allergens was assessed by the skin prick test and/or specific serum IgE. Food allergens included: milk, egg, wheat, soy, shrimp, fish and peanuts. Data was also researched through clinic’s registration system, total IgE levels and severity of asthma, according to Gina 2015.

Results: We studied 41 patients with a mean age of 39.5 years and 73% were women. When assessing the severity of asthma, 39% had severe asthma, 39% moderate, and 20% mild asthma. Fourteen percent of the patients had suggestive history of food allergy. The mean total serum IgE was 1171.8 IU/mL. Thirty-nine percent of the patients had sensitization to some of the tested food allergens. Of these, milk and eggs accounted for 25% each, followed by shrimp—20%. Wheat and peanuts accounted for 10% each of them, and soy and fish, 5% each of them. The group sensitized to food allergens had a higher total IgE level (1597 IU/mL), when compared to the group that was not sensitized to food allergens (912 IU/mL). It is well established in the literature that asthma is associated to different phenotypes, and therefore may be associated with varying degrees of treatment difficulties. It has been reported in the literature that food allergy might be a risk for complicated or poorly controlled asthma, not only in children but in adults as well, and was associated with asthma morbidity, including risk of hospitalizations and oral steroid use. Nevertheless, the prevalence of food allergy in adults with asthma is still not known. This study showed that nearly 40% of the allergic asthmatic patients with or without history of food allergy, had sensitization to major food allergens. These patients sensitized to food allergens also had higher levels of total serum IgE when compared with non-sensitized patients.

Conclusions: Due to the difficulty of control in some cases of asthma, different risk factors should be investigated, including food allergy. More studies should be performed to research these findings in large population. And it would have implications for the management of asthmatics, particularly those with severe disease.

PP003 Red gram (Cajanus cajan) proteins induce symptoms of atopic dermatitis in BALB/c mice following intraperitoneal route of exposure

Rinkesh Kumar Gupta, Akanksha Sharma, Kriti Gupta, Mukul Das, Premendra Dwivedi

CSIR-Indian Institute of Toxicology Research, Lucknow, India

Correspondence: Rinkesh Kumar Gupta - rinkeshgupta9@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP003

Introduction: Legumes play a major role in the induction of food allergic manifestations. Allergy to red gram has been reported in allergic rhinitis as well as BALB/c mice. Information about the atopic dermatitis (AD) like symptoms induced by red gram is yet to be explored. In this study, attempts have been made to elucidate the AD like symptoms induced by red gram proteins following intraperitoneal route of exposure.

Methods: To establish the correlation between red gram allergy and AD, we have studied the coexistence of AD and food allergy in red gram allergic patients (n = 210) and healthy individuals (n = 10 as a control) at the Department of Respiratory Medicine, King George Medical University (KGMU), India. Further, BALB/c mice were sensitized with red gram crude protein extract (CPE) via intraperitoneal route to explore the red gram induced AD like symptoms. Serum levels of specific IgE and IgG1 antibodies were measured by indirect ELISA. Anaphylactic signs and symptoms were evaluated 40 min after the challenge by two investigators using the scoring. Histopathological responses were analyzed in the skin of treated mice. Further, mast cell count was performed in the skin. Moreover, expression levels of cytokines, transcription factors and filaggrin were studied in the skin of treated mice.

Results: To observe the clinical prevalence of AD in red gram sensitized patients, 210 allergic patients were screened. Out of which 3.33% patients showed possible symptoms of AD, followed by positive SPT for red gram allergen. In the Balb/c mice, elevated levels of specific IgE and IgG1 in the serum along with symptoms of anaphylaxis were found in the treated mice when compared to their respective controls. Further, histopathological analysis of skin revealed characteristics of AD in the treated groups. Significantly enhanced numbers of mast cells were observed in the skin of treated mice as compared to control. Mixed profiles of GATA-3, T-bet, IL-4 and IL-13 at the mRNA were found in the skin of treatment groups when compared to their respective controls. Similarly, enhanced expressions of GATA-3, T-bet as well as filaggrin were observed at the protein levels in the skin of treated mice. We have endeavored to understand the allergenic potential of red gram in the context of AD because in our previous study, we have observed the health concern related to skin in the pigeon pea’s allergic patients. Increased levels of specific IgE and IgG1 antibodies were evident in treated group as compared to control group; illustrate the allergenic potential of red gram CPE. In our study, treated group mice have shown significantly fall in body temperature (4–5 °C) as well as symptoms of systemic anaphylaxis upon challenge with red gram CPE. Histopathological results showed the AD like pathological changes, including epidermal thickening, mixed inflammatory cellular infiltration along with hyperplasia indicating that these changes may be evidences for AD. In this study, elevated levels of mast cells were found in the skin, suggesting the massiveness bearing of red gram specific IgEs bound to mast cell receptors. Further, treated skin also over expressed with IL-4 and IL-13 and associated transcription factors like GATA-3 and reduced expression of T-bet at mRNA level, suggesting that local skin expression of Th2 cytokines have crucial role in the development of AD. Present study showed decreased level of filaggrin in the skin, supporting our finding related to the prevalence of AD induced by red gram.

Conclusion: Little is known regarding the association between food allergy and atopic dermatitis. In this report, intraperitoneal exposure of red gram proteins may lead to symptoms of atopic dermatitis in BALB/c mice.

PP004 Food allergy in young children age and the evaluation of clinical effectiveness of hypo-allergic formula

Rusudan Karseladze1, Liana Jorjoliani1, Lali Saginadze2, Mariam Tskhakaia3

1Tbilisi State University, Tbilisi, Georgia; 2Iashvili Children’s Clinic, Tbilisi, Georgia; 3Institute of Paediatrics, Tbilisi, Georgia

Correspondence: Rusudan Karseladze - rusakars@yahoo.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP004

Introduction: The Atopic Dermatitis caused by nutrition allergy is noticed in most of children till one year and from the etiological spectrum a nutritious sensitization frequently is caused by cow’s milk protein.

Our aim was the evaluation of clinical effectiveness of specialized, hydrolyzed cow’s milk albumin in children of early age diseased by atopic Dermatitis (AD).

Methods: There were under observation 20 children from 30 day up to one year, with AD. The including criteria were age, artificial feeding and existence of AD. The excluding criteria were: an individual intolerance of formula and mother’s refusal. The basis of diagnostics was a diagnostic algorithm of AD by Hanifin and Rajka [1]. A heaviness of AD is evaluated by means of standard criteria according to universally recognized SCORAD system.

Results: 16 children—first group with mild form of AD, in which SCORAD index amounted to 35.5–65.5 score,14 one-second group with moderate form-SCORAD index was 65.5–78.5 score. In 52% of observed children has been diagnosed IgE-depended allergy, in 20%—an increase of specific IgG4 antibodies level towards cow’s milk albumin, but in 28% a mixed variant. Hence is follows, that for the purpose of diet-therapy, the children with AD have been taking specialized hypo-allergic formulas, which is made on basis of hydrolyzed cow’s milk protein. The medicinal effectiveness of formula has been evaluated according to SCORAD index.

The results of research show, that in both groups have been noted a decreased of subjective showings in particular of itch and sleep disorder. In children who taking a hypo-allergic formula, are noted a good indicator of body’s weight and surplus of length, which points in favour of good endurance of formula. In 82% of diseased after 1–3 weeks from the beginning of diet-therapy, is noted a clinical improvements-decreased of skin’s inflammatory process has been proved according to subjective (itch, insomnia) and objective (erythema, dryness, humidity, excoriation) showings, which are fairly shown under SCORAD index.

Conclusion: A convincing and reliable results of a conducted research give a opportunity to make a conclusion, that to use a formula of diet-therapy in children with AD is expedient in specialized arsenal of children’s nutrition.

Reference
  1. 1.

    Hanifin JM, Rajka G. Diagnostic features of atopic dermatitis. Acta Derm Venereol Suppl (Stockh) 1980;92:44–7.

     

PP007 BAFF and PAF: assessing long term stability in dried blood samples

Katia Basello1, Gabriele Piuri2, Attilio Francesco Speciani3, Michela Carola Speciani4, Carla Camerotto4, Francesco Zinno5

1GEK srl c/o Cryolab, Rome, Italy; 2Inflammation Society, Orpington, United Kingdom; 3GEK srl, Milan, Italy; 4SMA srl, Milan, Italy; 5Department of Biomedicine and Prevention, Faculty of Medicine, “Tor Vergata” University, Rome, Italy

Correspondence: Katia Basello - katia.basello@gek-group.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP007

Introduction: The aim of this study is to evaluate the degradation over time of B Cell Activating Factor (BAFF) and Platelet-Activating Factor (PAF) in collected dried blood, evaluating the differences between two kinds of sample collectors: Whatman 903 Neonatal card (CARD) and Copan Nylon Swab (SWAB).

Methods: A dried blood spot is a common, moderately-invasive method for collecting patient blood from finger pricks. The blood samples are collected from 18 individuals. The collection of the samples is carried out in triplicate for both devices. Samples were stored at room temperature in the dark until serum extraction and analysis. Samples are assayed by Enzyme-Linked Immuno-Sorbent-Assay (ELISA) for BAFF (R&D Systems) and PAF (Elabscience). Serum extraction and ELISA assay were carried out 2 days (T2), 7 days (T7), 14 days (T14), 21 days (T21) and 28 days (T28) after collection. Results were presented as mean ± SEM.

Results: PAF values were stable over the time up to 21 days both for CARD and SWAB. At 28 days there was a reduction of up to 54.3 ± 6.76% for SWAB and up to 36.6 ± 5.5% for CARD (p < 0.001). As regards BAFF, values were stable until T21 while at T28 there was a decrease of up to 77.1 ± 6.3% for SWAB and up to 63.7 ± 4.5% for CARD (p < 0.001). According to Finkelman, there is a pathway of activation of immune system mediated by IgG, FcγRs, macrophages, and PAF. BAFF is a member of the tumor necrosis factor superfamily and an important regulator of peripheral B cell survival, maturation and immunoglobulin class-switch recombination. Many studies suggest that BAFF might modulate immune inflammation and could probably be one of the cornerstones of this IgG pathway of immune reaction. BAFF and PAF have both already been linked in non-atopic subjects to food reactions, supporting the possibility that these inflammatory molecules could be involved in non-IgE-mediated allergic reactions.

Conclusion: The data presented in this study should be considered for both clinical and research applications. The higher degradation of PAF compared to BAFF could be attributed to the different chemical nature of these two inflammatory molecules, lipid and protein respectively. The degradation over time of BAFF and PAF also depends on the type of technological support used for the collection of the specimen. Samples should be analysed as soon as possible and no later than 21 days from the time of collection to ensure greater stability of the values.

PP010 Diagnostic approaches to the differentiating food allergies from food intolerances

Olga Pakholchuk

Zaporizhia State Medical University, Zaporizhia, Ukraine

Correspondence: Olga Pakholchuk - bessikalo2009@live.ru

Clinical and Translational Allergy 2017, 7(Suppl 1):PP010

Introduction: Literature reviews showed that FA clinical manifestations on the skin of various degrees of severity related to foods ingestion can arise as a result of a number of disorders and only some of which can be defined as allergic.

The aim of the research was to identify diagnostic approaches to the differentiating food allergies from food intolerances in children.

Methods: Skin elements were identified in complex with anamnesis data and results of the laboratory data. Hypersensitivity to food was detected by the skin tests (patch and prick), levels of the specific IgE and/or oral challenge test. Gut permeability was identified with 6-h lactulose urinary excretion.

Results: 56 patients (age 1–36 months old) with food allergy with typical allergic symptoms related to food intake were included into the study in the outpatient department. Major part of the parents (67%) couldn’t clearly identify the causative product. Only 15 children (26%) had positive specific IgE to milk and/or egg. Skin tests were positive in 10 of the patients (17.8%). Oral challenge test with milk and/or egg was positive only in 7 children (12.5%). Skin lesions vary from urticaria to papulation. Commonly non-immune reactions were nonspecific, not itching and not intense. Nevertheless of the type of the food intolerance mechanism skin dryness was presented in the major part of the patients. Moreover lactulose was detected in urine in 76.7% of cases both in group with immune and nonimmune reactions. There was no association of the lactulose level with type of the skin lesions. But intestinal permeability correlated with skin dryness (p < 0.05).

Conclusion: The study revealed that gut permeability in children with skin manifestations of food allergy often overlapping with symptoms found in nonimmune disorders such as disorders of absorption. Skin dryness can be its’ phenotypical marker. Gut permeability is the purpose for additional dietary corrections in children with FA.

PP011 Validation of food hypersensitivity phenotypes using longitudinal observation and atopic sensitization data in the first 6 years of life

Olga Pakholchuk, Svitlana Nedelska

Zaporizhia State Medical University, Zaporizhia, Ukraine

Correspondence: Olga Pakholchuk - bessikalo2009@live.ru

Clinical and Translational Allergy 2017, 7(Suppl 1):PP011

Introduction: The aim of this study is to validate food hypersensitivity (FH) phenotypes in the survey using data of the 6-year examination and allergic sensitization assessment at 1, 3, and 6 years.

Methods: 196 children with FH symptoms diagnosed on the 1st and 2nd year of life were recruited in the outpatient department and completed 6-year follow-up. Skin prick testing and specific IgE detection was performed at 1, 3 and 6 years (n = 98, 53, 24, respectively). Using questionnaire and clinical examination and laboratory data at 6 m, 12 m, 2, 3 and 6 years we classified children into FH phenotypes: transient early, persistent, late-onset.

Results: It was found that non-immune FH mechanisms were commonly seen in patients with late-onset and persistent phenotype (p < 0.05). Children with transient FH symptoms both were as allergic, as non-allergic. Early onset phenotype patients more often had clear association with causative product and in almost ¾ developed food tolerance.

Conclusion: Immune FH more often manifests during first year of life. Late onset, especially after 2 y.o. as usual associated with food intolerance reactions, particularly if clear cause of the reactions is not seen.

PP012 Using Component Resolved Diagnosis (CRD) in food allergy improves diagnostic-therapeutic appropriateness and therefore optimises financial resources

Stefano Pattini1, Maria Teresa Costantino2, Silvia Peveri3, Danilo Villalta4, Eleonora Savi3

1Dermatology Department, Allergy Unit, Azienda Ospedaliero-Universitaria Policlinico di Modena, Modena, Italy; 2Centro Day Hospital Allergologia e Immunologia Clinica, ASST Carlo Poma Mantova, Mantova, Italy; 3Allergy Unit, G. Da Saliceto Hospital, AUSL Piacenza, Piacenza, Italy; 4Department of Laboratory Medicine, A.O.S. Maria degli Angeli, Pordenone, Italy

Correspondence: Stefano Pattini - pattini.stefano@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP012

Introduction: The aim of this study is to evaluate the percentage change of the diagnostic-therapeutic choice in complex polysensitized patients affected by food allergy, after using CRD compared to a first level survey (medical history and skin tests), along with an economic analysis of the patient’s overall management according to the two different approaches (assessment of higher costs and savings).

Methods: In this multicenter study in real life, 187 patients polysensitized to skin tests and with clinical symptoms related to an IgE mediated food allergy were recruited. Each patient was submitted to skin prick tests (SPT) with a standard panel of food allergens and to a blood sample in order to detect specific IgE against food recombinant molecules (CRD), which were chosen according to medical history and positivity to SPT, by ImmunoCAP method (Thermo Fisher Scientific®, Uppsala, Sweden) or, when not available, by Microarray ISAC 112 allergens system (Thermo Fisher Scientific®, Uppsala, Sweden). Then the first diagnostic-therapeutic hypothesis, based only on medical history and skin tests, was recorded for each patient and, after that, the second diagnostic-therapeutic choice (final) was made, the one which would be implemented considering the CRD outcome. Therefore, an evaluation of the change of the diagnostic-therapeutic choice was carried out, in percentage, between the first hypothesis and the final choice, analyzing statistically the results by the agreement coefficient (k index) and the Chi square test. Finally, a detailed analysis was conducted on the economic impact of a molecular approach to the overall management of the allergic patient in order to evaluate whether the increase in the diagnostic costs would be compensated and eventually exceeded by savings coming from the increasing diagnostic-therapeutic appropriateness.

Results: A change in the prescription of self-injected adrenaline has been observed in about 50% of patients (k index 0.56) and an overall saving of financial resources along with a higher diagnostic-therapeutic appropriateness has been pointed out too.

Conclusion: In this study there is only moderate agreement concerning prescription of self-injected adrenaline before and after performing CRD: as a result, it is highlighted the usefulness of CRD, at least in complex polysensitized patients, in indicating risk assessment and therefore the correct therapy of food allergy, thus resulting in a cost-saving approach.

PP013 Food IgG antibodies: study of long-term stability of dried blood samples

Gabriele Piuri1, Katia Basello2, Attilio Francesco Speciani3, Andrea Costanzi2, Francesco Zinno4

1Inflammation Society, Orpington, United Kingdom; 2GEK srl c/o Cryolab, Rome, Italy; 3GEK srl, Milan, Italy; 4Department of Biomedicine and Prevention, Faculty of Medicine, “Tor Vergata” University, Rome, Italy

Correspondence: Gabriele Piuri - gabriele.piuri@me.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP013

Introduction: A dried blood spot is a common, moderately-invasive method for collecting patient blood from finger pricks. The aim of this study is to evaluate the long-term stability in the collection and detection of food-specific IgG antibodies comparing two different kinds of sample collectors: Whatman Neonatal card 903 (CARD) and Copan Nylon Swab (SWAB). The blood samples are tested by IgG Enzyme-Linked Immuno-Sorbent-Assay (ELISA) for precision and accuracy.

Methods: The blood samples are collected from 18 individuals (10 females and 8 males). The collection of samples is carried out in triplicate for both devices. Serum samples are assayed for food-specific IgG. The specific IgG antibody responses are analyzed on a customized ELISA plate (Immunolab GmbH) wich detects total IgG for 33 food antigens in serum. Samples were stored at room temperature in the dark. Serum extractions and ELISA assays were carried out after 2 days (T2), 7 days (T7), 14 days (T14), 21 days (T21) and 28 days (T28). Since the Kolmogorov–Smirnov normality test revealed non-normal distribution of the parameters, results were presented as median and interquartile range (IQR).

Results: Over time, analyses show progressively smaller results both as regards the CARD and the SWAB (p < 0.001). While between T2 and T7 there were no statistically significant changes, in T14 there was a significant reduction of −17% (−0.45 to +0.03) to the initial value that is maintained up to T21. Between T21 and T28, there were no statistically significant differences regarding CARD, while for SWAB there was a further reduction of values of up to −29% (−0.46 to −0.08). As discussed by Ligaarden, the concentration of specific IgG for food reflects the use of that food in the diet. In addition, Finkelman showed a IgG-dependent mechanism of anaphylaxis which involves IgG, FcγRs on macrophages, basophils and neutrophils, complement-derived peptides C3a e C5a, B cell Activating Factor (BAFF) and Platelet Activating Factor (PAF). For a more accurate study of the possible interaction between these mechanisms associated with IgG, it is important to know precisely the advantages and disadvantages of the most used methods in this area of investigation.

Conclusion: Considering the deterioration of biological samples over time it is important that the dosage of food IgG antibodies in dried blood is carried out as quickly as possible and in any event within 21 days of collection.

PP014 Diagnostic algorithm for gluten intolerance in children

Vera A. Revyakina, Marina A. Kiseleva, Elena D. Kuvshinova, Inna A. Larkova, Anton A. Shekhetov

Federal State Budgetary Scientific Institution «Federal Research Centre of Nutrition, Biotechnology and Food Safety», Moscow, Russia

Correspondence: Vera A. Revyakina - 5356797@mail.ru

Clinical and Translational Allergy 2017, 7(Suppl 1):PP014

Introduction: The gluten intolerance is associated with celiac disease and Allergy to gluten, the criteria for the differential diagnosis of which is still insufficiently developed.

The aim of this study is the development of a diagnostic algorithm for gluten intolerance in children for the purpose of adequate diet therapy application to prevent development of complications and severe forms of the disease.

Methods: Under supervision there were 42 children with chronic diarrhea and symptoms of impaired intestinal absorption. The diagnostic algorithm consisted of the following stages. The first stage—the detection of the risk groups for gluten enteropathy. These include: (1) immediate relatives of patients with celiac disease; (2) close relatives with allergic diseases; (3) children with gastrointestinal symptoms resistant to standard therapy; (4) children, lagging in physical development and with symptoms of impaired intestinal absorption; (5) patients with dermatitis herpetiformis and diseases that can be associated with celiac disease. At the second stage children included in the risk group were subjected to screening diagnostics. We used the BIOCARD TM Celiac Test (Finland), which allows to determine antibodies to tissue transglutaminase (IgA). Patients with a confirmed diagnosis of celiac disease and positive (BIOCARD TM Celiac Test) test was not included in further examination. The third stage of gluten intolerance diagnostics was in-depth examination of children with gastrointestinal and skin manifestations of Allergy, including anamnesis and clinical symptoms, determination of total IgE, IgG, IgA, IgM and specific IgG and IgE antibodies in the blood serum.

Results: Three groups of patients were identified. The first group consisted of 23 children with positive allergen-specific IgE antibodies to gluten and wheat and to cow’s milk protein in serum. In 10 children from the second group IgE and IgG antibodies to gluten and wheat serum were identified at the same time. They had gastrointestinal symptoms within a few hours after eating a certain amount of foods containing gluten (individual for each child). The third group of patients included 9 children with IgG antibodies to gluten and wheat serum. Clinically they mainly had skin rashes.

Conclusion: The staged diagnostic algorithm for gluten intolerance in children allows to determine the mechanism of gluten intolerance and to prescribe required elimination diet and treatment aimed at prevention of serious complications.

PP015 Accuracy of skin prick test to access plant food allergy

Diana Silva, André Moreira, José Plácido, Alice Coimbra

Serviço de Imunoalergologia, Centro Hospitalar de São João E.P.E., Porto, Portugal

Correspondence: Diana Silva - disolha@gmail.com

Clinical and Translational Allergy 2017, 7(Suppl 1):PP015

Introduction: Plant food allergy diagnosis is challenging due to the different implicated foods, clinical manifestations and geographic diversity. We aimed to assess the diagnostic accuracy of single food allergenic proteins combined with plant and food skin prick test extracts (SPT) to evaluate plant food allergy.

Methods: This is a cross-sectional retrospective study. All SPT performed in an allergy department of Porto, Portugal from 09/2014 to 12/2015 (n = 3141 patients) were included and those evaluating sensitization with extracts to fresh fruits (soy, watermelon, banana, apple, peach, kiwi, avocado, fig), nuts (walnut, hazelnut, almond, pinenut, peanut and chestnut), lipid transfer proteins (LTP), profilin and latex were selected (n = 189 patients). Clinical and demographic data, sIgE, SPT with fresh foods, and open food challenges (OFC) results were reviewed from patients records. Plant food allergy syndromes were identified and the accuracy of the skin tests were calculated using medical diagnosis as the gold standard. Continuous data are presented as median and interquartile range and categorical as n(%). Mann-whitney and Chi square were used to compare differences between groups.

Results: Of all the tests, 89(48%) were performed due to