Activated T cells and soluble molecules in the portal venous blood of patients with cholestatic and hepatitis C virus-positive liver cirrhosis. Possible promotion of Fas/FasL-mediated apoptosis in the bile-duct cells and hepatocyte injury

We investigated the immune responses of patients with cholestatic and hepatitis C virus-positive (HCV-positive) liver cirrhosis by analysing T-cell subsets and cytokine levels in the portal and peripheral veins, using flow cytometry and enzyme-linked immunosorbent assay. In cholestatic liver cirrhosis, the proportion of natural-killer (NK) T cells and interleukin (IL) 6 and IL-18 levels in the portal venous blood were significantly higher than those in the peripheral venous blood. In HCV-positive liver cirrhosis, the proportions of NK T cells and Fas⁺ T cells and IL-6 and soluble Fas levels in the portal venous blood were significantly higher than those in the peripheral venous blood. These results suggest that in these diseases, activated T cells and soluble molecules in portal venous blood may promote Fas/FasL-mediated apoptosis of the bile-duct cells and hepatocytes, and contribute to the deterioration in liver function as an inevitable result of positive feedback.