Reduced natural killer cell activity of lymphocytes from patients with Werner's syndrome and recovery of its activity by purified human leucocyte interferon.

Natural killing (NK) activities were measured in peripheral blood lymphocytes (PBL) from 14 patients with Werner's syndrome (WS), and the results were compared with those of 187 normal individuals at different ages. The NK activities of healthy donors were demonstrated a characteristic and invariable manner in accordance with the age and the sex, whereas the activities of WS patients were considerably reduced irrespective of the age and the sex. When normal PBL were preincubated with WS sera containing anti-lymphocyte antibodies (ALA) plus rabbit complement, the NK activities of the surviving PBL were markedly reduced when compared with those of PBL treated with other heterologous ALA of rabbit origin in the same manner. PBL from WS patients treated with purified human leucocyte interferon augmented the NK activity even beyond the range of controls. These results suggested that NK activities in WS patients were reduced in a manner similar to that in normal old individuals. The ALA reactive to NK cells in WS patients may participate in the reduction of NK activities. The augmentative effect of interferon on NK activities in WS patients may also suggest the possible blocking of potent NK activities by an unknown mechanism rather than an intrinsic defect of their NK cells.