Abstract
Rosette formation of hepatocytes was studied in 16 patients with autoimmune hepatitis (AIH). Rosettes were found more frequently in AIH than in viral chronic active hepatitis (CAH). Morphological features of rosettes varied with the change of clinical stage. The morphology of hepatocytes forming rosettes were divided into two types, degenerative and regenerative types. In immunohistochemistry, IgG-producing cells in the portal and periportal areas were observed predominantly in AIH than in viral CAH. Infiltrating cells around rosettes were mainly nonB-nonT cells. In electron microscopic examinations, mononuclear cells and plasma cells were observed in contact with rosette forming hepatocytes. A percentage of CD8-positive cells were decreased and that of CD19-positive cells was increased in peripheral blood of AIH patients. These findings suggest that antibody dependent cell-mediated cytotoxicity may participate in the hepatocyte damage in AIH.
