Effects of ribavirin on cytokine production of recall antigens and phytohemaglutinin-stimulated peripheral blood mononuclear cells. (Inhibitory effects of ribavirin on cytokine production).

AIM To evaluate the effects of ribavirin on cytokine production of recall antigen and PHA-stimulated PBMC obtained from healthy individuals. MATERIALS AND METHODS PBMC were challenged with tetanus toxoid (5 microg/mL) and PHA (10 microg/mL) in absence or presence of ribavirin at different concentrations (1, 10 and 100 (microM). Parallel sets of wells containing PBMC exposed to medium alone were used as negative controls. On day 3 after initiation of the cultures, IL-2, IFN-gamma, IL-4, IL-10, TNF-alpha content were determined in supernatants of PBMC from the different individuals. RESULTS The effects of ribavirin on cytokine released by human PBMC in response to PHA and TT showed a great variation among individuals. No significant changes were observed between 1-10 microM concentrations in the production of TNF-alpha, IFN-gamma and IL-10 by both PHA and TT-stimulated PBMC. Ribavirin inhibited TNF-alpha, IFN-gamma, and IL-10 in both PHA and TT-stimulated PBMC at 100 microM (p <0.05). At this concentration, ribavirin induced an increase of 124% in the production of IL-2 by PHA-stimulated PBMC (p <0.05). CONCLUSIONS The present data suggest that ribavirin may cause diverse effects on immunoregulatory cytokine secretion with changes in the Th1/Th2 balance.