A New Diagnostic Criteria of Wheat-Dependent, Exercise-Induced Anaphylaxis in China

BACKGROUND: Wheat-dependent, exercise-induced anaphylaxis (WDEIA) is an allergic reaction induced by intense exercise combined with wheat ingestion. The gold standard for diagnosis of WDEIA is a food exercise challenge; however, this test is unacceptable for Chinese WDEIA patients and unable to be approved by the Ethics Committee of Chinese hospitals due to substantial risk. There are no diagnostic criteria for Chinese WDEIA patients. The aim of present study was to propose new practical diagnosis criteria for Chinese WDEIA patients. METHODS: We prospectively included 283 clinically diagnosed WDEIA patients from January 1, 2010 to June 30, 2014, and in the meanwhile, three groups were enrolled which included 133 patients with the history of anaphylaxis induced by food other than wheat, 186 recurrent urticaria patients, and 94 healthy participants. Clinical comprehensive evaluation by allergists used as the reference gold standard, receiver operator characteristic (ROC) curves were plotted, areas under curve (AUC) for specific immunoglobin E (sIgE) were compared to evaluate the diagnostic value of IgE specific to wheat, gluten, and ω-5 gliadin. Patients were followed up by telephone questionnaire 1 year after diagnosis. RESULTS: We reviewed 567 anaphylactic reactions in 283 WDEIA patients. Of these anaphylactic reactions, 415 (73.3%) reactions were potentially life-threatening anaphylaxis. Among the 567 anaphylactic reactions, 75% (425/567) occurred during exercise. The highest AUC (0.910) was observed for sIgE for gluten, followed by omega-5 gliadin (AUC 0.879). Combined gluten- and ω-5 gliadin-specific IgE testing provided sensitivity and specificity of 73.1% and 99.0%, respectively. During the 1-year follow-up period, repeat anaphylaxis was rare when patients observed strict avoidance of wheat products combined with exercise or other triggering agents. CONCLUSIONS: In this study, we proposed diagnostic criteria and management of WDEIA patients in China. Our present study suggested that confirmed anaphylactic reactions triggered by wheat with positive sIgE to gluten and omega-5-gliadin may provide supportive evidence for clinicians to make WDEIA diagnosis without performing a food exercise challenge.