Interferon gamma-secreting HCV-specific CD8+ T cells in the liver of patients with chronic C hepatitis: relation to liver fibrosis – ANRS HC EP07 study*

Summary.  Little is known about the role of specific hepatitis C virus (HCV) CD8+ T cells in liver damage, especially for the progression of fibrosis, during the highly variable course of chronic C hepatitis. The aim of this study was to investigate the presence of HCV-specific CD8+ T cells in the liver of patients with chronic C hepatitis and to examine their clinical significance by relating the response to liver fibrosis and progression rate, serum viral load, serum aminotransferase levels, inflammatory activity and in situ characteristics of the intrahepatic infiltrate. Fifteen patients were prospectively included in the study. Intrahepatic lymphocytes were tested for interferon gamma (IFNg) production in response to HCV class I-restricted epitopic peptides using enzyme-linked immunospot analysis. Liver biopsy samples were evaluated for fibrosis, fibrosis progression rate, activity, and in situ number of CD8+ cytotoxic lymphocytes and apoptotic cells. An IFNg-specific CD8+ T-cell response was detected in the liver samples of 47% of patients which was significantly related to a lower stage of fibrosis (P = 0.02) and a lower progression rate of fibrosis (P = 0.01). It was neither related to the number of cytotoxic lymphocytes infiltrating the liver nor to hepatocyte apoptosis. In conclusion, our results indicate that the presence of HCV-specific IFNg-secreting T cells in the liver of patients with chronic C hepatitis is associated with low liver fibrosis and fibrosis progression rate, suggesting that these IFNg-secreting T cells might limit the progression of liver damage.