Basophil Activation Marker CD203c Is Useful in the Diagnosis of Hen’s Egg and Cow’s Milk Allergies in Children

Abstract

Background: The diagnosis of food allergy (FA) is usually based on oral food challenge tests (OFC). However, OFCs occasionally induce severe adverse reactions. CD203c expression on basophils is emerging as a potential diagnostic index. We evaluated whether CD203c expression on basophils would be a useful marker of OFC-associated symptoms in hen’s egg and cow’s milk allergies in children. Methods: Seventy-one patients who had been diagnosed with FA based on OFCs or a convincing history of FA symptoms in the Department of Pediatrics, Sagamihara National Hospital, were recruited. CD203c expression was assessed after stimulation with antigens (egg white, ovomucoid, milk or casein) using allergenicity kits. The CD203c stimulation index (SI = the allergen-induced CD203c expression level divided by the baseline expression level) and the threshold of CD203c expression (the minimum concentration of antigen to induce CD203c SI ≧2) were analyzed in association with tolerance acquisition. Results: For the CD203c SI, the areas under the receiver-operating characteristic curve were 0.72 for egg white, 0.82 for ovomucoid, 0.84 for milk and 0.67 for casein. The positive predictive value for the threshold of CD203c expression was 94.7% for egg white, 100% for ovomucoid, 85.7% for milk and 75.0% for casein. Conclusions: Assessment of food antigen-induced CD203c expression on basophils is useful to determine if children will outgrow FA as well as in decision making regarding whether or not to perform OFCs.