Sensitivity and specificity of recombinant ω-5 gliadin-specific IgE measurement for the diagnosis of wheat-dependent exercise-induced anaphylaxis

Background: A recent study has shown that the measurement of specific IgE antibodies to B-cell epitope peptides of wheat omega-5 gliadin (Pep A) and high molecular weight glutenin subunit (Pep B) are useful to diagnose wheat-dependent exercise-induced anaphylaxis (WDEIA). Aims of the study: We sought to compare the sensitivity and specificity of the in vitro tests for measuring the specific IgE antibodies to recombinant omega-5 gliadin (r omega-5 gliadin) with those for wheat, gluten, Pep A, and Pep B in identification of patients with WDEIA. Methods: Fifty patients with WDEIA, 25 healthy subjects and 25 patients with atopic dermatitis with specific IgE antibodies to wheat but without experience of allergic reactions after ingestion of wheat products were enrolled in this study. The concentrations of specific IgE antibodies were measured using ImmunoCAP(TM). The empirical receiver operating characteristics curves (ROC) for each test were prepared and the areas under the ROC curve (AUC) were compared. Results: In patients with WDEIA, the sensitivities of the allergen-specific IgE tests for wheat, gluten, Pep A, Pep B and r omega-5 gliadin were 48%, 56%, 76%, 22%, and 80%, respectively. The seven of 10 WDEIA patients with no specific IgE antibodies to r omega-5 gliadin had specific IgE antibodies to Pep B. The highest AUC (0.850) was observed in the test for r omega-5 gliadin. Conclusions: Measuring the concentration of specific IgE antibodies to r omega-5 gliadin is more useful than to wheat, gluten, or Pep A in the identification of patients with WDEIA.