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 distribut ion of CD8(+) T-cell subsets in HIV+ children and correlate the findings wi th degree of immunosuppression and HIV viral burden. Methods: By means of 3-color flow cytometry, percentages of CD38(+)DR(+), C D28(+), and CD57(+) CD8(+) T-cell subsets were examined in RP (n=15) and no n-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 m ean CD4(+) T-cell percentages and HIV RNA levels. Analysis of covariance wa s 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 t han 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 C D4(+) 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 pr ogression in pediatric HIV infection.