DECREASED SUPEROXIDE ANION AND HYDROGEN-PEROXIDE PRODUCTION BY NEUTROPHILS AND MONOCYTES IN HUMAN IMMUNODEFICIENCY VIRUS-INFECTED CHILDREN AND ADULTS

The higher susceptibility to serious bacterial infections of patients, particularly children, infected with the human immunodeficiency virus (HIV) may be due in part to defective function of their phagocytic cells. We examined the ability of polymorphonuclear cells and monocytes of HIV-infected children and adults to generate superoxide anion (SO) and hydrogen peroxide (HP) and compared it with that of cells from normal children and adults. SO was measured by reduction of cytochrome c and HP by horseradish peroxidase-dependent oxidation of phenol red. The cells were incubated in 96-well plates at 37-degrees-C for 2 h before the assay and the nonadherent cells then removed. Readings for SO were taken at 10, 30, 60, and 120 min after stimulation with phorbol myristate acetate; HP production was assayed after 90 min. The SO and HP production by polymorphonuclear cells and monocytes from both HIV-infected children and adults was consistently found to be markedly lower than that of cells from age-matched controls. The magnitude of the difference in response between patients and control cells also increased with increasing incubation time. Thus, phagocytic cells from HIV-infected children and adults are defective in their ability to generate reactive oxygen intermediates, and this defect may make them more vulnerable to bacterial and fungal infections.