Abstract
Several kinds of killer cell activities including natural killer (NK) and lymphokine activated killer (LAK) activities, and subpopulations of lymphocytes were studied in 12 children with growth hormone (GH) deficiency before and during treatment with the intramuscular administration of 0.5U per Kg methionyl growth hormone weekly. The results as follows:
(1) The mean of natural killer (NK) activity against K 562 cells in 12 patients before GH therapy was significantly (p<0.05) lower than that in normal controls. NK activity in the patients, 3 months after initiation of therapy, was elevated to the level comparable to that in normal controls and persisted normally thereafter.
(2) No significant difference could be found in the mean value of interferon-γ, interleukin-2 (IL-2) or OK 432 augmented NK cell activity and prostaglandin E2 producing suppressor cell activity to NK cells in the patients and in normal controls, and these augmented NK activities persisted normally during GH therapy in the patients.
(3) Although both the mean values of IL-2 and OK 432 induced LAK activities against Raji cells in 9 patients were significantly (p<0.01) lower before therapy, there were no appreciable differences between those in the patients during therapy and those in normal controls.
(4) NK and IL-2 induced LAK activities in each patient during therapy continued without difference with normal controls.
(5) A significant low percentage of Leu 7+ cells in 11 patients was observed in the patients both before and during GH therapy.
These data suggest that GH deprivation may cause the defective killer cell activities and number of killer cells, and that GH replacement therapy elevated the function of killer cells, though the number of killer cells remained at a low level.
