Immune Mechanisms and the Action of Interferon in Chronic Hepatitis B Virus Infection

Cytotoxic T lymphocytes can eliminate cells infected with hepatitis B virus. A defect of T lymphocyte-mediated cytolysis seems to exist in chronic hepatitis B infection. T cell-mediated lysis is dependent on HLA antigens of the infected host and this may explain the increased or decreased frequency of particular HLA antigens in chronic carriers of hepatitis B virus. This virus may decrease the concentration of HLA antigens expressed on liver cells. Interferon increases the HLA antigen expression on T lymphocytes and hepatocytes, thereby enhancing T lymphocyte-mediated lysis of infected liver cells and elimination of the hepatitis B virus.