Lymphokine-activated cytotoxicity in peripheral blood mononuclear cells of severely immunocompromised HIV-infected patients.

The authors determined the natural killer (NK) and lymphokine-activated killer (LAK) activities of peripheral blood mononuclear cells (PBMCs) from a severely immunocompromised (CD4 cell counts < 100/mm3) group of AIDS patients, using K562 and U937 target cells. An increase in cytotoxicity was observed in the PBMCs of all 17 patients following a 48 h incubation with the combination of 400 U/ml of recombinant gamma interferon plus 20 U/ml of natural interleukin-2. Although NK and LAK activities were significantly higher in healthy controls than in patients, patients' LAK activity was higher than the NK activity of controls. The authors also demonstrated that the use of medium containing fetal bovine serum, when compared with medium containing autologous serum, increases NK activity without affecting LAK activity. Lymphokine augmentation of cytotoxicity is achievable in severely immunocompromised AIDS patients and might be of benefit in delaying opportunistic infections and malignancies.