In vivo enhancement of NK-cell activity by thymopentin.

Natural killer (NK) activities of fresh and IL-2-precultured peripheral blood mononuclear cells (PBMC) were investigated in 13 elderly subjects before and after thymopentin (TP-5) treatment and in 12 age-matched controls. The NK activity of fresh PBMC was found to be significantly higher in subjects given TP-5 at 50 mg s.c. three times per week for one month. Conversely, this type of treatment with TP-5 did not significantly modify the cytotoxic capacity of IL-2-precultured PBMC.