Treatment-resistant expansion of CD8+CD28 - Cells in pediatric HIV infection

There is a disease stage-dependent loss of CD28 expression on T cells in HI V-infected children. In this study, T cell recovery, in particular CD28 exp ression on T cells, was analyzed after initiation of highly active antiretr oviral therapy in a group of eight mostly treatment-naive HIV-infected chil dren. plasma HIV-RNA levels were recorded, and numbers of CD4, CD8, CD4+CD2 8+, and CD8+CD28+ cells were determined by two-color flow cytometry. Values after 12 mo of therapy were compared with age-matched, seronegative contro l subjects. CD4 recovery to subnormal values was observed in all children. CD8+CD28+ cells recovered and were within the normal range after 12 mo of t herapy (patients, 703 +/- 250 cells/mu L; controls, 789 +/- 269 cells/mu L) , whereas CD8+CD8- cells (546 +/- 269 cells/mu L) remained significantly ex panded compared with age-matched controls (140 +/- 35 cells/mu L). Expansio ns of CD8+CD28- cells persisted even in cases with long-term suppression of viral replication. Highly active antiretroviral therapy in HIV-infected ch ildren induces substantial but incomplete T cell recovery.