Skip to main content

Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

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

  1. 1.

    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.

  2. 2.

    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