Expression of Th1 and Th2 type cytokines responding to HBsAg and HBxAg in chronic hepatitis B patients

The cytokine pattern on viral antigen recognition is believed to exert a pr ofound influence on the resolution of viral infections and viral clearance. This study was initiated to investigate whether a cytokine imbalance orien ted toward Th2 type response plays a role in chronic hepatitis B. Cytokine profiles of peripheral blood mononuclear cells associated with chronic hepa titis B were analysed by RT-PCR. Upon HBsAg stimulation, expression of IFN- gamma, IL-2, IL-4, and IL-10 was detected in 41%, 8%, 41%, and 50% of the p atients, respectively. Among these cytokines, the expression of IFN-gamma w as associated with high levels of serum AST/ALT. However, we could not prov e that Th2 type cytokines had a protective effect on hepatocytes. Upon HBxA g stimulation, there was no recognizable association of cytokine patterns w ith AST/ALT levels. In conclusion, production of a Th1 cytokine, IFN-gamma, by HBsAg-reactive cells was associated with hepatocyte damage in chronic h epatitis B, while no counteracting effect of Th2 cytokines produced by thos e cells was observed.