Identification of intrahepatic lymphocyte subpopulations in patients with drug‐induced allergic hepatitis

Intrahepatic lymphocyte subpopulations were studied in eight cases of drug-induced allergic hepatitis (DIAH) by the immunoenzymatic technique using monospecific T cell antibodies and other reagents. In peripheral blood, the CD4: CD8 ratio in DIAH was higher than that in normal controls. In liver tissue, CD8 positive lymphocytes were predominant, and these cells were attached to the surface of hepatocytes. Leu 7, CD4 and CD11 positive lymphocytes were scarce and were not attached to hepatocytes. HLA-class I was displayed on the cell membrane of hepatocytes. These results suggest that cytotoxic T cells, which are CD8 positive, CD4 negative and CD11 negative, may play an important role in the pathogenesis of liver cell injury in patients with DIAH.