Depressed spontaneous natural killing and interferon augmentation in patients with malignant lymphoma.

A substantial proportion (44%) of peripheral blood lymphocyte samples from 41 patients with malignant lymphoma have been shown to have depressed or undetectable levels of natural cytotoxicity against the leukaemic cell line K562 in a 4-hr [51Cr]-release assay. No correlation was found between low levels of natural killer (NK) cell activity and either the age of the patients, total or differential white blood counts, or the type or stage of disease. Furthermore, pre-treatment of lymphocytes with human lymphoblastoid (Namalva) interferon failed to enhance NK levels in 5/11 patients with Hodgkin's disease and 5/8 patients with non-Hodgkin's lymphoma, and was in contrast to the response of control peripheral blood lymphocytes assayed under the same test conditions. The lack of responsiveness to interferon of peripheral blood NK cells from lymphoma patients was not wholly associated with those patients shown to have low levels of spontaneous NK activity.