Background Several studies have shown that interleukin (IL)-4 and interferon-gamma (IFN-γ) are important for the regulation of immunoglobulin E (IgE) production and that IL-18 and IL-12 induce IFN-γ.
Objective IFN-γ 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-γ production by IL-18-stimulated PBMCs was positively correlated with IFN-γ production by IL-12-stimulated PBMCs (P < 0.05). However some atopic patients showed discrepancy between the levels of IFN-γ 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.