A quantitative ultrastructural analysis of the leukocytes in contact with hepatocytes in chronic active hepatitis, with a cytochemical detection of mononuclear phagocytes.

In an attempt to characterize in vivo the immune cells cytotoxic to hepatocytes in patients with chronic active hepatitis (CAH), a quantitative ultrastructural analysis of leukocytes in close contact with hepatocytes was performed in 13 patients with untreated HBsAg-negative CAH. Mononuclear phagocytes were identified by detection of endogenous peroxidase. Of the leukocytes, 8.3-4.1% were mononuclear phagocytes, 12.5-25.8% were large lymphocytes with a prominent secretory apparatus, assumed to represent mostly killer cells (T-cytotoxic cells and/or null cells), 12.2-56.8% were small lymphocytes poor in cytoplasmic organelles, and 0-45.8% were plasma cells. Patients with high serum transaminase levels had significantly more mononuclear phagocytes (P less than 0.001) and significantly fewer plasma cells (P less than 0.001) and small lymphocytes (P less than 0.001) than patients with lower disease activity. The profile of the leukocytes in contact with hepatocytes in these CAH patients suggests that mononuclear phagocyte-mediated mechanisms play an important role in hepatocyte necrosis in vivo.