Recent advances of in vitro tests for the diagnosis of food-dependent exercise-induced anaphylaxis.

Food-dependent exercise-induced anaphylaxis (FDEIA) is a special form of IgE-mediated food allergy and exhibits allergic symptoms in combination of causative food-intake and triggers such as exercise. As the causative foods and the condition of triggers vary among patients, diagnosis of FDEIA is not always easy. Serum food-specific IgE tests, which are widely used in the diagnosis of FDEIA, have rather low sensitivity, because the tests mostly utilize crude extracts of foods. Concept of using defined allergen molecules has been proposed as the term "component-resolved diagnostics" for diagnosis of IgE-mediated allergy. Use of purified allergens such as recombinant omega-5 gliadin turned out to highly improve its sensitivity and specificity of the tests in the diagnosis of wheat-dependent exercise-induced anaphylaxis (WDEIA). Recently, CD203c expression-based basophil activation test (BAT) is reported to be useful in identifying adult patients with WDEIA and predicting causative allergens in WDEIA, when combined with appropriate allergens. Detection of serum allergen levels possibly gives useful information whether food challenge tests have been performed with sufficient strength.