The role of autoimmunity in hepatitis C infection.

Viral infections are considered a possible trigger of autoimmune diseases. In autoimmune liver diseases the hepatotropic viruses, especially hepatitis C virus (HCV), have received particular attention as possible etiological agents. The present study was undertaken to investigate the relation between hepatitis virus infections and autoimmune liver diseases. We found a very low incidence of HCV infection in patients with autoimmune liver diseases. Only 5% (n = 7) of patients with AIH types I and III had antibodies against HCV antigens, but only two of these seven were HCV-RNA positive. Similar results were obtained in patients with PBC and PSC. Furthermore, the coexistence of LKM autoantibodies with chronic HC is a rare event and less common than low-titer ANA and SMA in viral liver diseases. In conclusion, a link between hepatitis viruses B or C and AI-liver diseases is very unlikely. Autoantibodies in viral liver diseases appear to be an expression of a generalized immune activation by cytokines, as observed during interferon treatment in viral liver diseases.