RESUMO
BACKGROUND: Allergic rhinitis is the most common atopic reaction to allergens and may persist for many years if not treated. It is never lethal, though it may cause morbidity. The IgE synthesis is regulated by inheritance, antigen exposition and cytokines; specially Th2 cells, through secretions of the IL4 e IL5 that favor IgE production and inflammation rich in eosinophils. OBJECTIVE: To determine the difference of IgG4 serum levels, gamma interferon, and interleukins of patients with allergic rhinitis, with and without immunotherapy, and healthy patients. MATERIAL AND METHODS: In an observational, transversal, prospective, comparative and open study 82 (100%) patients were recruited and divided into three groups. Group 1 included 15 patients with allergic rhinitis diagnosis and positive skin tests without immunotherapy; group 2, 15 patients with allergic rhinitis diagnosis and positive skin tests with immunotherapy; group 3, 52 healthy patients. RESULTS: IL-4, IL-5, IL-6 and IL-12 values were higher in both groups of allergic rhinitis, compared with healthy group. There were differences in the IL-5 concentrations that were less in patients with allergic rhinitis and vaccine than in those without vaccine. The values of IgG4 and gamma interferon did not vary and were not found in the studied groups. CONCLUSION: The present study proved the existence of significant differences, showed increments in the interleukin values among healthy and allergic patients, despite allergic rhinitis is a local phenomenon. It is probable that the above is related to the genetic tendency to produce a Th2 cytokines pattern which is a characteristic of allergy. Allergen immunotherapy modified significantly the IL-5 levels as well as the other studied interleukins.