K-cell-mediated antibody-dependent cellular cytotoxicity in chronic active liver disease

These studies were designed to determine the ability of antihepatocyte antibodies from patients with chronic active liver disease to induce killing of rabbit hepatocytes by normal lymphocytes. Normal subjects and patients with chronic persistent hepatitis or chronic active liver disease served as sources of sera, and normal human peripheral lymphocytes and their subsets (T-enriched, K-enriched, and B) served as effectors. Only sera from patients with chronic active liver disease possessed membrane-reactive IgG directed against the surface of rabbit or human hepatocytes. After pretreatment of rabbit hepatocytes with sera from patients with chronic active liver disease, marked cytotoxicity mediated by normal lymphocytes was observed. K-enriched cells mediated the antibody-dependent cellular cytotoxicity, whereas T-enriched cells and B-cells did not. Heat-aggregated human IgG blocked the antibody-dependent cellular cytotoxicity. These data suggest that sera from patients with chronic active liver disease contain IgG antihepatocyte antibodies, which are capable of inducing normal K-cells to kill rabbit hepatocytes in vitro.