title: T cell-mediated cytotoxicity against HBsAg-coated Chang cells in patients with chronic hepatitis: evidence for cytotoxicity mediated by delayed hypersensitivity T cell reaction.
abstract: T lymphocytes from 7 (21%) of 34 patients with chronic hepatitis showed positive cytotoxicity against HBsAg-coated Chang cells. This positivity was observed in HBsAg-negative patients having positive blast transformation responses to HBsAg, as well as in patients convalescing and recovered from acute B hepatitis. Levels of S-GPT in these patients were not different from those showing no cytotoxicity. T cell-mediated cytotoxicity against HBsAg-coated hepatocytes in HBsAg-negative patients thus may have no significant pathogenetic role in destruction of hepatocytes and may represent anamnestic response of sensitized T lymphocytes to HBsAg. Positive cytotoxicity against HBsAg-coated Chang cells was also found in 3 of 17 patients with HBsAg-positive chronic hepatitis. All positive cases exhibited blast transformation responses to HBsAg and low HBsAg titers in their sera. Levels of S-GPT in these patients were significantly higher than in those showing no cytotoxicity, suggesting possible presence of T cell-mediated liver cell damage in these patients. T lymphocytes from asymptomatic HBsAg carrier showed no cytotoxicity to HBsAg-coated hepatocytes and no blast transformation responses of lymphocytes to HBsAg. From the results of the parallel occurrence of T cell-mediated cytotoxicity and blast transformation responses to HBsAg, and of presence of lymphotoxin in the supernatant co-cultured HBsAg and cytotoxicity-positive lymphocytes, it seemed likely that T cell-mediated cytotoxicity in our system might be mediated by lymphokine produced by T cells as a result of delayed hypersensitivity reaction in vitro.
mesh_terms: D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D006510:Hepatitis B Antibodies / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D006521:Hepatitis, Chronic / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008233:Lymphotoxin-alpha / Q000032:analysis; D013602:T-Lymphocytes, Cytotoxic
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D008233:Lymphotoxin-alpha