T-CELL SUBSETS AND CYTOKINES IN ALLERGIC AND NONALLERGIC CHILDREN .1.ANALYSIS OF IL-4, IFN-GAMMA AND IL-13 MESSENGER-RNA EXPRESSION AND PROTEIN-PRODUCTION

Interleukin 4 (IL-4) and IL-13 are key cytokines inducing switching to immunoglobulin E (IgE), whereas interferon gamma (IFN-gamma) acts inh ibitory on this process, We analysed whether differences existed in IL -4, IFN-gamma and IL-13 mRNA expression and protein production between T cells of children,vith allergic and non-allergic asthma, atopic der matitis and healthy control children, IL-4 mRNA expression was increas ed in stimulated T cells of children with allergic asthma and atopic d ermatitis, but not in those with non-allergic asthma as compared with healthy controls, Thus the increase in IL-4 expression can be consider ed as an underlying mechanism of the allergic disease profess and not so much of the asthmatic state of the children. In unstimulated T cell s of children with atopic dermatitis increased IFN-gamma mRNA expressi on with a reduced IFN-gamma protein production was found, indicating a post-translational defect in IFN-gamma. Differences in IL-13 expressi on between the groups were not significant, but IL-13 was significantl y correlated with the height of the radio-allergo-sorbent test (RAST) class and with the severity scoring of atopic dermatitis (SCORAD) inde x, This indicates the clinical relevance of IL-13 for the degree of al lergen-specific sensitization and severity of atopic dermatitis, In co nclusion, the imbalance in 1L-4 and IFN-gamma secretion in patients wi th atopic dermatitis may reflect general T cell activation in the pres ence of an intrinsic defect of IFN-gamma secretion. (C) 1997 Academic Press Limited.