IFN-γ production in response to IL-18 or IL-12 stimulation by peripheral blood mononuclear cells of atopic patients

Background Several studies have shown that interleukin (IL)-4 and interferon-gamma (IFN-gamma) are important for the regulation of immunoglobulin E (I-E) production and that IL-18 and IL-12 induce IFN-gamma. Objective IFN-gamma production in response to,IL-18 or IL-12 stimulation was investigated in peripheral blood mononuclear cells (PBMCs) of atopic patients with various levels of serum IgE. Methods Cytokine production from PBMCs was measured following stimulation with a non-specific stimulator (phytohemagglutinin: PHA), IL-18 or IL-12 in 12 healthy controls and 26 atopic patients with various serum IgE levels. Results IFN-gamma production by IL-18-stimulated PBMCs was positively correlated with IFN-gamma production by IL-12-stimulated PBMCs (P < 0.05). However some atopic patients showed discrepancy between the levels of IFN-<gamma> production stimulated by IL-12 and by IL-18. Conclusions The results shown here suggest the presence of abnormalities in the IL-12 and/or IL-18 signalling pathways, such as genetic defects in the atopic patients.