Virus- and immune-mediated liver damage in hepatitis.

It has been assumed for many years that liver damage associated with hepatitis B virus (HBV) infection is due to cytolytic immune reactions directed at viral antigens expressed on infected liver cells. Recent studies, however, suggest that in some clinical settings, changes in the HBV genome, possibly selected by immune pressure, can interfere with the export of viral proteins from hepatocytes and lead to direct virus-induced liver damage.