Spontaneous cell-mediated (SCMC) and antibody-dependent cellular cytotoxicity (ADCC) in patients with acute and...

spontaneous (SCMC) and antibody-dependent (ADCC) cellular cytotoxicity was studied in patients with aucte viral hepatitis B and chronic active hepatitis (CAH) B and non-A, non-B. Chang cells displaying the liver-specific protein LSP on the plasma membrane were used as target cells. SCMC and ADCC in acute hepatitis B were not different from normal controls. SCMC and ADCC in chronic active hepatitis B as well as in non-A, non-B were significantly elevated in comparison to normal controls. In additional experiments, the influence of patients sera on SCMC and ADCC was studied. Autologous serum from CAH patients significantly reduced cytotoxicity in SCMC and ADCC assays. This inhibitory capacity of patients sera was attributable to immune complexes, as ultracentrifugation studies and determination of immune complexes of fractionated sera demonstrated.