In Vitro IgE, Interleukin 4, and Interferon Gamma Production in Children with Differing Serum IgE Concentrations

Interleukin 4 (IL-4) and interferon-gamma (IFN-γ) have been shown to play a role in the regulation of in vitro IgE production by cells from adults. Little information is available regarding the role of these cytokines in influencing IgE production by cells from children. Children ages 3-17 were classified into two groups based upon serum IgE concentrations (>600 U/ml vs. <200 U/ml). Lymphocytes were evaluated for phenotype and IgE production. In vitro IL-4 and IFN-γ production was measured as was the effect of these cytokines on in vitro IgE production by cells obtained from subjects in the two study groups. Children with elevated serum IgE concentrations produced greater amounts of IL-4 than those with lower serum concentrations of IgE. At low dosages of IL-4 (10U) cells from the patients with lower serum IgE concentrations were more sensitive to the effects of IFN-γ, while at higher concentrations of IL-4 (300U) cells from those with higher serum concentrations of IgE were more sensitive to the effects of IFN-γ. The group with higher serum IgE levels had a significantly higher proportion of CD4+ T cells and a greater proportion of cells positive for CD4 and CD29. There are differences in lymphocyte phenotype and IL-4 production in patients with high and normal concentrations of serum IgE. These differences may be important in understanding the basis for different serum IgE concentrations in children.