Volume 3 Supplement 3
Evidence for higher sensitivity of recombinant Tri a 36 compared to omega-5-gliadin for diagnosis of wheat food allergy
© Baar et al; licensee BioMed Central Ltd. 2013
Published: 25 July 2013
Wheat is one of the most important food allergen sources. Using natural wheat allergen extracts for serological diagnosis of wheat-induced food allergy false positive test results are frequently obtained, in particular in grass pollen allergic patients. Therefore, Tri a 19, an omega-5-gliadin, which is known as a major allergen in wheat dependent exercise induced anaphylaxis (WDEIA) and in wheat food allergy in children, is widely used for the serological diagnosis of wheat-induced food allergy.
We have recently characterized Tri a 36, a low molecular weight glutenin as new major wheat food allergen. Here we compared recombinant Tri a 36 with ImmunoCAPs containing omega-5-gliadin for the detection of specific IgE antibodies in a population of wheat food allergic children (n=23) and grass pollen allergic patients (n=21). Wheat food allergic children had a clear clinical history of wheat food allergy with symptoms clearly attributable to wheat ingestion. Grass pollen allergic patients suffered from grass pollen-induced respiratory allergy but regularly ate wheat products without any clinical symptoms. Sera from both populations were tested by ImmunoCAPs containing wheat extract or omega-5-gliadin and by IgE ELISA to rTri a 36.
Using wheat extract-based ImmunoCAPs all but one of the wheat food allergic patients showed allergen-specific IgE levels >0.35 kUA/L but 17 out of the 21 grass pollen allergic patients gave false positive test results. Eleven (i.e.,48%) of the wheat food allergic patients showed >0.35 kUA/L IgE against omega-5-gliadin and two of the grass pollen allergic patients gave false positive test results. Using rTri a 36, 14 (i.e., 61%) of the wheat food allergic patients were diagnosed and only one grass pollen allergic patient gave a false positive test result. Each of the sera from the wheat food allergic patients with IgE reactivity to omega-5-gliadin also reacted with rTri a 36.
Our results indicate that rTri a 36 has higher sensitivity and specificity than omega-5-gliadin for the diagnosis of wheat food allergy.
Disclosure of interest
This study was supported by the Christian Doppler Research Association, Vienna Austria, by a research grant from Phadia/Thermofisher, Uppsala, Sweden and by European Commission’s Seventh Framework Programme under grant agreement No. 261357.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.