The depressed natural killer (NK) activity, antibody-dependent cellular cytotoxicity (ADCC) and N K cytotoxic factor cytotoxicity in untreated non-Hodgkin's lymphoma patients were found to be elevated after chemotherapy. In vitro treatment of the effector N K cells with interferon a could augment the NK activity in normal subjects and treated patients to a comparable degree. Chemotherapy mainly affected the post-binding events in the NK cytotoxic process by causing an increase in the active killing potential of the N K cells. This study provides a better understanding of changes in the NK cytotoxic mechanism in non-Hodgkin's lymphoma patients and the role of interferon in this process.
production in untreated cases of NHL [7]. In this study we show that the NK, ADCC and AK cytotoxicities were restored to almost normal levels in the NHL patients after completion of therapy. The post-binding events in the NK-cell-mediated cytotoxic mechanism were more depressed in the untreated cases, becoming elevated after treatment. When the lymphocytes were exposed to leukocyte interferon (IFN-c 0 in vitro, the augmentation of NK activity was restored to almost normal levels in the treated patients. This study provides a further insight into the alterations in the NK-cell-mediated cytotoxic mechanism in cases of NHL and reiterates a therapeutic role for interferon in these patients.