Interleukin-4 Production in Asthmatic Patients During Allergen Immunotherapy: A Preliminary Study

Abstract

Background Chronic inflammation and cytokine amplification play a major role in the pathogenesis of asthma. Allergen immunotherapy in atopic asthma has been shown to be effective, but the precise immunologic mechanisms for clinical improvement are poorly understood. CD4+T-cells from atopic asthmatics produce increased levels of the cytokines such as interleukin-4 (IL-4), compared with CD4+T-cells from nonatopic nonasthmatic individuals and these cytokines are believed to be directly involved in allergic disease process. It is not clear if IL-4 secretion patterns change during immunotherapy. Objectives Monitoring IL-4 levels may be very useful in evaluating the effectiveness and response to allergen immunotherapy. Methods Peripheral blood mononuclear cells were obtained from healthy nonasthmatic controls (n = 5) and from atopic asthmatic patients (n = 5) prior to immunotherapy and at 3 and 6 months after initiation of immunotherapy to monitor IL-4 secretion in unstimulated and grass allergen-specific stimulated mononuclear cells. Changes in IL-4 secretions were related to clinical response to immunotherapy. Results Mean IL-4 secretion was lower in controls than in asthmatics but the difference was not statistically significant. In asthmatics 3 months after starting immunotherapy mean IL-4 secretion significantly decreased (p <.002) in both grass antigen-specific stimulated cultures and un-stimulated cells. This pattern persisted at 6 months. Conclusion In atopic asthmatics mean IL-4 secretion was significantly decreased during immunotherapy however this change was not allergen-stimulation dependent at the dose response chosen.