Decreased response to interleukin-2 of cancer patients in terms of augmentation of natural killer cell activity

The effects of interleukin-2 (IL-2) on natural killer (NK) cell activity were examined in both healthy persons and cancer patients. The NK activity of peripheral blood lymphocytes from 29 healthy donors was augmented by IL-2 treatment in all cases. However, in 14 out of 50 cancer patients NK activity was not augmented by IL-2. The rate of NK augmentation in a group of cancer patients was significantly lower than that in a healthy control group. When the cancer patients were divided into each clinical stage, NK augmentation was as follows: in stage I, 3 out of 3; in stage II, 11 out of 12; in stage III, 10 out of 18; and in stage IV, 12 out of 17. The rate of NK augmentation was significantly lower in cancer patients of stages III and IV. The rate of NK augmentation was also dependent on the performance status (PS) of cancer patients. The NK augmentation of cancer patients of PS 0 to 2 was not significantly different from that of normal controls, whereas the rate of NK augmentation was significantly lower in cancer patients of PS 3 and 4.