Interleukin-4 and interferon-gamma production by peripheral blood mononuclear cells from food-allergic patients

The aim of this study was to investigate whether patients with food allergy had a cytokine imbalance of interleukin (IL)-4 and interferon-gamma (IFN-gamma) production. Diagnostic procedures including skin prick tests, determination of food-specific serum IgEs, and positive double-blind, placebo-controlled, food challenges identified 15 adult patients. They were compared with 15 age- and sex-matched healthy subjects. Peripheral blood mononuclear cells (PBMC) were incubated for 24, 48, and 72 h in the presence of phytohemagglutinin plus phorbol myristate acetate. After mitogen stimulation, culture supernatants from patients with food allergy contained significantly less IFN-gamma but increased IL-4 when compared with healthy controls. Secretion of IL-4 was maximal at 24 h and IFN-gamma secretion was maximal at 72 h. There was no correlation between cytokine secretion in vitro and serum IgE level. These findings demonstrated that an imbalance of IL-4 and IFN-gamma production is present in food allergy, as documented in other allergic diseases, but other mechanisms are probably also involved.