CD4(+) CD8(+) RATIO OF LIVER-DERIVED LYMPHOCYTES IS RELATED TO VIREMIA AND NOT TO HEPATITIS-C VIRUS GENOTYPES IN CHRONIC HEPATITIS-C/

The pathogenic mechanisms that lead to chronic hepatitis C are unknown . As hepatitis C virus (HCV) has been shown to induce T cell response, we assessed whether a particular T lymphocyte subset could be prefere ntially detected in the liver of patients with chronic hepatitis C in relation to viraemia or HCV genotypes. The immunophenotypes of liver-d erived lymphocytes were analysed in 26 patients by flow cytometry and immunohistochemistry. Viraemia was quantified by branched DNA assay. U sing this assay, HCV RNA was not detectable in six patients. HCV RNA w as detected in 20 patients, and titres ranged from 8 to 137 x 10(6) Eq /ml. Genotyping was performed using a line probe assay. Type 1a, 1b, 2 a, 3a and 4a were found to infect 2, 10, 2, 7 and 3 patients, respecti vely. The CD4(+)/CD8(+) ratio of liver-derived lymphocytes was signifi cantly higher (P < 0.01) in patients with detectable viraemia than in patients without detectable viraemia. In contrast, neither the percent age of gamma/delta T lymphocytes nor that of CD2(+) CD57(+) cells was different in the groups. When comparing the CD4(+)/CD8(+) ratio, the p ercentage of gamma/delta T lymphocytes or CD2(+)CD57(+) cells accordin g to genotype, the differences were not significant. These results sug gest that the CD4(+)/ CD8(+) ratio of liver-derived lymphocytes is rel ated to viraemia but not to HCV genotypes in patients with chronic hep atitis C, and that T lymphocytes may be involved in the pathogenesis o f liver lesions in chronic hepatitis C.