IgE antibodies to ω-5 gliadin in children with wheat-induced anaphylaxis

Background: Wheat can cause severe immunoglobulin E (IgE)-mediated systemic reactions including anaphylaxis but knowledge on relevant wheat allergens at the molecular level is scanty. Methods: Seven children (aged from 6 months to 13 years) experiencing from 2 to 10 anaphylactic reactions in a year after eating food-containing wheat were examined. Purified ω-5 gliadin was used as an allergen in IgE enzyme-linked immunosorbent assay (ELISA) and in skin prick testing (SPT). Wheat CAP radioallergosorbent test (RAST) and SPT were also examined. Results: All seven anaphylactic children, but none of 15 control subjects had IgE antibodies to ω-5 gliadin in ELISA. Five of the six tested anaphylactic children showed positive SPT to ω-5 and crude gliadin, and all seven had positive wheat CAP RAST and SPT. One child was challenged with wheat, which caused anaphylaxis. After adherence to a wheat-free diet four children remained symptomless and three experienced one to two anaphylactic reactions. Conclusion: The present results show that wheat ω-5 gliadin is a major sensitizing allergen in children with wheat-induced anaphylaxis. They also suggest that ω-5 gliadin IgE ELISA could be used as a diagnostic test for this severe allergy.