Simultaneous evaluation of lymphocyte subpopulations in the liver and in peripheral blood mononuclear cells of HCV‐infected patients: relationship with histological lesions

Summary Intrahepatic lymphocytes are believed to be involved in the immunopathogenesis of hepatitis C virus (HCV) infection and the evolution of HCV‐induced hepatitis. In the present study, we examined the three main intrahepatic lymphocyte subsets, namely CD3+CD56− conventional T lymphocytes, CD3+CD56+ natural T (NT) lymphocytes and CD3−CD56+ natural killer (NK) lymphocytes in HCV‐infected patients. The proportion of each lymphocyte subset was evaluated both in liver biopsies and in samples of peripheral blood lymphocytes (PBL) by flow cytometry in 21 patients with histologically proven chronic hepatitis C. Simultaneously, alanine aminotransferase (ALT) levels, viral load and histological lesions were assessed. Neither NT nor NK populations correlated with any biochemical, viral or histological parameters. Furthermore, Vα24+ NT lymphocytes showed no preferential enrichment in the liver of HCV‐infected patients. Regarding conventional T lymphocytes, a highly significant linear correlation was found between intrahepatic CD3+CD56− T lymphocytes and the Knodell score, a numerical score for assessing histological activity and fibrosis (r = 0·715, P