Liver tissue expression of CD80 and CD95 antigens in chronic hepatitis C: relationship with biological and histological disease activities

The well known discrepancy between cytotoxic T lymphocyte (CTL) infiltratio n in the liver and disease biological activity, as assessed by alanine amin otransferase (ALT) levels, during the course of chronic hepatitis C virus ( HCV) infection, suggests the possible failure of cytotoxic mechanisms devot ed to virus clearance. To further investigate the biological events involve d in CTL-mediated lysis, i.e. B7/CD28 costimulatory and Fas/Fas-ligand path ways, the CD80 and CD95 antigen expression in liver tissue specimens from c hronically HCV-infected patients was evaluated. The results were analysed i n relation to serum ALT values and the histological activity (HAI) of liver disease. The data provide evidence for a strong and comparable hepatocyte CD80 and C95 structure expression in chronically HCV-infected livers. CD80- and CD95-carrying liver cells were more frequently distributed at the peri portal region of the hepatic lobule, above all near piecemeal necrosis area s, among infiltrating CTL. On the other hand, a negative correlation was fo und between liver tissue expression of both antigens and serum ALT activity . The relationship with HAI was not statistically significant. The results imply that HCV infection triggers CD80 and CD95 molecule expression on hepa tocytes. Further studies are required to clarify the relevance of such a fi nding in the context of virus-host interactions.