Defective natural killer cell activity and deficient production of interferon-gamma in children with acute...

Natural killer (NK) cell activity, OK-432-augmented-NK cell activity, concentrations of interferon-gamma (IFN-gamma) in the culture supernatants of lymphocytes stimulated with OK-432, and subsets of NK cells and memory T cells were analyzed in 42 children with acute lymphoblastic leukemia (ALL) receiving maintenance chemotherapy. Natural killer and augmented-NK cell activities, and concentrations of IFN-gamma in the supernatants of cultured lymphocytes, were significantly lower in the patients with ALL than in age-matched control children. Among the NK cell subsets, proportions of CD57+ cells in the patients with ALL were significantly higher than in the controls, and proportions of a memory T cell subset (CD4+ CD29+ T cells) in the patients were also significantly higher than in the controls. These results suggest that the function of NK cells and memory T cells that are considered as IFN-gamma producing cells, may be defective in ALL, and that CD57+ cells and CD4+ CD29+ cells may be resistant to or recover rapidly from suppression by cytotoxic chemotherapy.