Natural killer cell activity associated with aging and sex in humans.

Abstract

The effect of aging and sex on natural killer (NK) cell activity in humans was investigated. There were no significant differences in both the age- and sex-related NK cell activities or without polyinosinic acid-polycytidylic acid stimulation. The mitogenic response of peripheral blood lymphocytes in the aged group (aged 70-86 yr) was significantly depressed compared with that in the young adult group (aged 20-30 yr). The NK cell activity of the aged subjects is apparently operative, and may be important in defense against neoplasia since extensive immunodeficiencies are known to be associated with aging.