Objective: To reveal the clinical utility of an IgE test specific to ω-5 gliadin in the diagnosis of immediate-type wheat allergy.
Methods: We detected ω-5 gliadin-specific IgE in sera from all patients examined for wheat-specific IgE in our allergy clinic between January and October, 2008. The diagnostic value of the test was analyzed against the true diagnosis of wheat allergy based on oral wheat challenge or convincing clinical history. Subjects comprised 233 patients (median age, 3.6 years), 59 patients were diagnosed with wheat allergy, and 174 were judged to have no wheat allergy.
Results: The prevalence of being diagnosed as wheat allergy was 68% in the patients with CAP score 2 to ω-5 gliadin IgE (n=31), and 87% in those with CAP score 3 (n=15). All of the 3 patients with CAP score 4 or more were wheat allergic. However, 24% of patients with wheat allergy showed negative results (<0.35 UA/ml). According to the data, we proposed the probability curve of ω-5 gliadin-specific IgE.
Conclusions: IgE testing specific to ω-5 gliadin can offer a useful clinical marker for the diagnosis of immediate-type wheat allergy. But the data should always be evaluated with wheat-specific IgE titers, because of the low clinical sensitivity to detect the patients with wheat allergy.