Steven Sievers1,2, Harshadrai M Rawel3, Karl Peter Ringel4, Bodo Niggemann1, Kirsten Beyer1,5. 1. Pediatric Pneumology and Immunology, Charité Universitätsmedizin, Berlin, Germany. 2. Department of Biology, Chemistry and Pharmacy, Free University, Berlin, Germany. 3. University of Potsdam, Potsdam, Germany. 4. Karl-Peter Ringel Immunologische Laboratorien, Aachen, Germany. 5. Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Abstract
BACKGROUND: Wheat is one of the most common food allergens in early childhood. In contrast to other food allergies, wheat-specific IgE correlates badly with clinical symptoms and relevant components have been identified mostly for wheat-depended exercise-induced anaphylaxis. Moreover, a high percentage of patients present with immediate type symptoms but wheat-specific IgE cannot be detected with commercial available systems. OBJECTIVE: We addressed the question whether the IgE recognition pattern between wheat allergic (WA) and clinically tolerant (WT) children differs in order to identify individual proteins useful for component-resolved diagnostics. METHODS: Sera of 106 children with suspected wheat allergy, of whom 44 children had clinical relevant wheat allergy and 62 were tolerant upon oral food challenge, were analyzed for wheat-specific IgE using the ImmunoCap system as well as immunoblots against water and salt soluble, and water-insoluble protein fractions. 40 randomly selected sera were analyzed for specific IgE to ω5-gliadin. RESULTS: Sixty-three percent of the WT and 86% of the WA children were sensitized to wheat with >0.35 kUA /l in ImmunoCAP analysis. We could confirm the role of α-, ß-, γ-, and ω-gliadins, and LMW glutenin subunits as major allergens and found also IgE binding to a broad spectrum of water- and salt-soluble protein bands. It is of great importance that wheat allergic and tolerant patients showed IgE binding to the same protein bands. WT and WA did not significantly differ in levels of ω5-gliadin-specific IgE. CONCLUSIONS & CLINICAL RELEVANCE: Children with challenge proven clinical relevant food allergy and tolerant ones had a similar spectrum of IgE binding to the same protein bands. These findings imply that component-resolved diagnostics might not be helpful in the diagnostic work-up of wheat allergy.
BACKGROUND:Wheat is one of the most common food allergens in early childhood. In contrast to other food allergies, wheat-specific IgE correlates badly with clinical symptoms and relevant components have been identified mostly for wheat-depended exercise-induced anaphylaxis. Moreover, a high percentage of patients present with immediate type symptoms but wheat-specific IgE cannot be detected with commercial available systems. OBJECTIVE: We addressed the question whether the IgE recognition pattern between wheat allergic (WA) and clinically tolerant (WT) children differs in order to identify individual proteins useful for component-resolved diagnostics. METHODS: Sera of 106 children with suspected wheatallergy, of whom 44 children had clinical relevant wheatallergy and 62 were tolerant upon oral food challenge, were analyzed for wheat-specific IgE using the ImmunoCap system as well as immunoblots against water and salt soluble, and water-insoluble protein fractions. 40 randomly selected sera were analyzed for specific IgE to ω5-gliadin. RESULTS: Sixty-three percent of the WT and 86% of the WA children were sensitized to wheat with >0.35 kUA /l in ImmunoCAP analysis. We could confirm the role of α-, ß-, γ-, and ω-gliadins, and LMW glutenin subunits as major allergens and found also IgE binding to a broad spectrum of water- and salt-soluble protein bands. It is of great importance that wheat allergic and tolerant patients showed IgE binding to the same protein bands. WT and WA did not significantly differ in levels of ω5-gliadin-specific IgE. CONCLUSIONS & CLINICAL RELEVANCE: Children with challenge proven clinical relevant food allergy and tolerant ones had a similar spectrum of IgE binding to the same protein bands. These findings imply that component-resolved diagnostics might not be helpful in the diagnostic work-up of wheatallergy.