CYTOKINE PRODUCTION IN CHILDREN OUTGROWING HEN EGG ALLERGY

Background Approximately 40 to 80% of egg-allergic children outgrow eg g allergy after 2 to 5 years. Objective and methods To detail the immu nologic mechanisms involved in the development of tolerance to egg pro teins, the balance between interleukin 4 (IL4) and interferon-gamma (I FN-gamma) synthesis in patients with active atopic dermatitis allergic to hen egg and in those outgrowing hen egg allergy was evaluated. Res ults A marked increase in IL4 and a decrease in IFN-gamma synthesis by peripheral blood lymphocytes following ovalbumin (OVA) specific in vi tro stimulation was observed in active atopic dermatitis. In contrast, OVA-induced IL4 synthesis in patients in remission was comparable to that in normal individuals. An intriguing finding was higher productio n of IFN-gamma by lymphocytes from ovalbumin-insensitive patients in r emission as compared to normal individuals following antigen stimulati on, although cell proliferation in OVA-stimulated lymphocytes was redu ced in patients during remission. Conclusion OVA antigen may be capabl e of inducing a population of Th1-type cells to produce cytokines such as IFN-gamma, resulting in suppression of Th2-type responses, i.e. IL 4 secretion. We speculate that the changes in the balance of relevant antigen-induced cytokine synthesis seen in such patients may be causal ly associated with the improvement in their clinical status.