RESUMO
PURPOSE: The aim of this study was to assess the clinical usefulness and added diagnostic value of specific IgE antibodies to wheat, gluten, and ω-5 gliadin in diagnosing wheat allergy and distinguishing wheat anaphylaxis. METHODS: This study included 196 children who visited Ajou University Hospital for suspicious food allergy. The subjects were divided into 2 groups: the wheat allergy (WA) and non-wheat allergy (non-WA) groups. Patients with wheat allergy were further divided into 2 subgroups according to their symptoms: the wheat allergy with anaphylaxis (WA(Ana)) and wheat allergy without anaphylaxis (WA(Non-Ana)) groups. Serum concentrations of total IgE and specific IgE antibodies to wheat, gluten and ω-5 gliadin were measured. RESULTS: The median values of specific IgE antibodies to wheat, gluten and ω-5 gliadin were significantly higher in the WA group than in the non-WA group, and the positive decision points (95% specificity) were at 3.12, 2.61, and 0.21 kUA/L, respectively. The combination of specific IgE antibodies to wheat and ω-5 gliadin resulted in the highest accuracy of 93.9% in diagnosing wheat allergy. In differentiating the WA(Ana) group from the WA(Non-Ana) group, only specific IgE antibody to ω-5 gliadin showed a significant difference at the optimal cutoff point of 1.56 kUA/L. CONCLUSION: Our results show that the individual levels of specific IgE antibodies to wheat, gluten or ω-5 gliadin may have a considerably high accuracy in diagnosing wheat allergy and that specific IgE antibody to ω-5 gliadin may be particularly useful in predicting wheat anaphylaxis.