The nature of piecemeal necrosis in chronic active hepatitis.

On the basis of histological studies, it is proposed that the type of liver-cell death in piecemeal necrosis is apoptosis. The characteristic inconspicuousness of apoptosis explains why the mode of hepatocyte elimination in piecemeal necrosis has hitherto remained obscure. Cell-mediated immune attack induces apoptosis, not classical necrosis, and the occurrence of apoptosis in piecemeal necrosis links the observed morphological changes in chronic active hepatitis with the other evidence for an autoimmune pathogenesis. It is significant that apoptosis does not evoke inflammation or fibroplasia. In attempting to elucidate the cause of the fibrosis that accompanies progression to cirrhosis in chronic hepatitis, it may thus be more relevant to study the effect on fibroblasts of substances liberated during lymphocyte-hepatocyte interactions than the death of the hepatocytes.