Monocyte-mediated-antibody-dependent cellular cytotoxicity in malignant lymphoma and solid tumors

Monocyte-mediated-antibody-dependent cellular cytotoxicity (MO-ADCC) was studied in 21 patients with Hodgkin's disease (HD), 15 patients with a long-lasting remission of HD, 11 patients with non-Hodgkin's lymphoma (NHL), 11 patients with solid tumors, and 15 normal controls. Lymphocyte ADCC (LY-ADCC) was evaluated in 12 patients with HD and 9 normal controls. Monocytes lymphocytes were isolated with cell-scatter monitored counterflow centrifugation providing high purity and yield. Antibody-dependent cellular cytotoxicity was evaluated by means of DNA flowcytometry, using antibody-coated chicken erythrocyte targets (CRBC). In comparison with normal controls MO-ADCC was significantly increased in HD (P less than 0.0005), NHL (P less than 0.005), and solid tumors (P less than 0.005). In patients in long-lasting complete remission of HD, MO-ADCC was in the normal range. Lymphocyte-ADCC of 12 patients with HD was similar to that of 9 normal controls. In all experiments LY-ADCC was invariably lower than MO-ADCC of the same donor, indicating the monocyte as the most potent effector cell towards CRBC targets. Results indicate the following: (1) purified cell suspensions of both lymphocytes and monocytes are essential to unravel their role as effector cells; (2) LY-ADCC in HD is similar to normal controls; (3) MO-ADCC enhancement is not uncommon in malignant lymphoma and several solid tumors; (4) normal MO-ADCC in a group of successfully treated patients with HD suggests a disease-related induction of enhanced MO-ADCC.