Interleukin-4, interferon-gamma and interleukin-5 in peripheral blood of children with moderate atopic asthma

Background In asthmatic inflammation, TH2 cells play an important role. TH2 cells specifically secrete cytokines like IL-4 and IL-5. IL-4 stimulates IgE production and IL-5 is involved in hemopoiesis, chemotaxis, priming and activation of eosinophils. IFN gamma, produced by TH1 cells, has an inhibitory action on IgE production.Objectives To investigate the TH1/TH2-cell pattern in the cytokine production of peripheral blood of asthmatic children. We determined IL-4, IFN gamma and IL-5 in serum and in supernatants of unstimulated and stimulated (24h with Concanavaline A) cultures of peripheral blood mononuclear cells (PBMCs) in 22 children with moderate asthma (mean age 9.3 years) and in 17 healthy controls (mean age 10.3 years). All children visited the outpatient department (OPD) where history taking, physical examination and blood sampling took place. Children younger than 8 years of age performed symptom and peak flow registration during 1 week after the visit to the OPD.Results The number of eosinophils were significantly higher in children with asthma, compared with healthy controls. The concentration of IFN gamma in supernatants of cultures of stimulated PBMCs was significantly lower and the ratio of IL-4/IFN gamma was significantly higher in children with asthma compared with healthy controls. The FEV1 was directly and IgE was inversely related to the concentration of IFN gamma in supernatants of cultures of stimulated PBMCs.Conclusion IFN gamma may play an important role in the pathophysiology of childhood atopic asthma.