Proliferative responses of lymphocytes to food antigens are useful for detection of allergens in nonimmediate types of food allergy.

Food allergy is clinically classified into two types, immediate and nonimmediate. Radioallergosorbent test (RAST) is a sensitive procedure for the diagnosis of IgE-mediated hypersensitivity but not for other types of hypersensitivity. There is not yet a sensitive blood examination for detection of allergens in nonimmediate types of food allergy. Of the total number of subjects in our study, twenty-two children had nonimmediate types of food allergy (hen's egg, cow's milk, soybean, or buckwheat flour), atopic dermatitis, allergic tension fatigue syndrome or pulmonary hemosiderosis. For these children, manifestations of the allergy did not appear earlier than 2 hours after ingestion of the offending food. Eighteen children in the study developed acute urticaria, angioedema, or bronchial asthma appearing within 2 hours of the challenge. Fifteen nonatopic healthy children were selected as controls. Proliferative responses of peripheral blood mononuclear cells (PBMCs) to food antigens were measured in nonimmediate types of food allergy. The proliferative responses of PBMCs to each offending food antigen in patients with nonimmediate types of food allergy were significantly higher than those of healthy controls and patients with immediate types of food allergy, respectively. Moreover, in each case with nonimmediate type, the proliferative responses to food antigens other than the offending food were not detected. When PBMCs were twice stimulated with the offending food antigen, the same results were obtained. These results indicate that the proliferative response of PBMCs to food antigens is specific to each offending food antigen in nonimmediate types of food allergy. Taken together, proliferative responses of PBMCs to each food antigen are useful for detection of allergens in nonimmediate types of food allergy.