Abstract
Studies of asymptomatic carriers of hepatitis B antigen (HB Ag) have suggested that the hepatitis B virus may not be directly damaging to liver cells and it is possible that the hepatocellular necrosis which accompanies acute hepatitis may be induced by immunological reactions directed at viral antigenic determinants on the surface of infected cells. Immunological reactions may also be implicated in the pathogenesis of active chronic hepatitis. Although antibodies which are commonly present in the serum are probably not of primary importance in the immunopathology, recent studies have demonstrated liver-specific immune responses, both humoral and cellular, which may be more directly related to the pathogenesis.