Natural killer activity, tumor necrosis factor-α, and interferon-γ, production in HIV-infected children at various stages of disease

We have compared the levels of natural killer (NK) activity and of tumor necrosis factor-α (TNF-α) and interferon-γ, (IFN-γ) production in human immunodeficiency virus (HIV)-infected children (HIV⁺) with those of HIV- negative (HIV^-) children born to HIV⁺ mothers. NK activity was significantly lower in HIV⁺ children than in HIV^- controls (p <0.05), except for the group with the lowest CD4⁺ count and with opportunistic infections. Cells with NK phenotype were also fewer in the HIV⁺ group, although there was an increase in activated T lymphocytes DR⁺ CD3⁺ (p <0.05), related to increased CD8⁺ CD57⁺ cells. TNF-α and IFN-γ production was greater in HIV⁺ patients than in controls (p = 0.052; p <0.05). This difference was due to patients with lymphocytic interstitial pneumonitis (LIP), who had significantly higher levels of TNF-α and IFN-γ than the other HIV⁺ children (p <0.002; p <0.003) or the control group (p <0.001). Neither p24 antigenemia nor decreased numbers of CD4⁺ cells were associated with increased levels of these cytokines.