Comparison of CD8⁺ T-cell subsets in HIV-infected rapid progressor children versus non-rapid progressor children

Background: CD8⁺ T-cell subsets have not been adequately described in HIV-infected (HIV⁺) children classified with respect to disease progression as rapid-progressors (RPs) and non-rapid progressors (non-RPs). Objective: The purpose of this investigation was to determine the distribution of CD8⁺ T-cell subsets in HIV⁺ children and correlate the findings with degree of immunosuppression and HIV viral burden. Methods: By means of 3-color flow cytometry, percentages of CD38+DR⁺, cd28⁺, and CD57⁺ CD8⁺ T-cell subsets were examined in RP (n = 15) and non-RP (n = 36) HIV⁺ children and in HIV-exposed but uninfected (n = 11) and HIV-unexposed (n = 8) children. The CD8⁺T-cell subsets were correlated with mean CD4⁺T-cell percentages and HIV RNA levels. Analysis of covariance was used for group comparisons for the control of the covariate of age. Results: The HIV-exposed and HIV-unexposed controls were not different from each other in CD8⁺T-cell subset percentages, except that the DR-CD38⁺CD8⁺ T-cell percentages were higher in the exposed controls than in the unexposed controls. RPs had a higher mean percentage of DR⁺CD38⁺CD8⁺ T cells than non-RPs and both control groups, and RPs had higher viremia than non-RPs. CD38⁺CD8⁺ T-cell percentages did not correlate with viral burden as it has been seen to do in HIV⁺ adults. Percentages of CD28⁺CD8⁺ T cells were lower in HIV-infected children than in controls. There was a positive correlation of percentage of CD28⁺CD57-CD8⁺ T cells with CD4⁺ T-cell percentages in each HIV-infected group. Conclusion: CD8⁺ T cells become activated (dual expression of DR and CD38) and lose CD28, some acquiring CD57, in relation to rapidity of disease progression in pediatric HIV infection.