Immune reconstitution in human immunodeficiency virus-infected children receiving highly active antiretroviral therapy: a cohort study

Background. Highly active antiretroviral therapy (HAART) has brought about rapid declines in HIV-1 RNA concentrations and an increase in CD4(+) counts in HIV-1-infected children. These changes are often accompanied by clinical improvement; however, the extent to which immune reconstitution occurs is not known. Design. We compared two cohorts (n = 35) of HIV-1-infected children to evaluate the effects of HAART on immune recovery. Cohort 1 (C1) included clinically well children receiving HAART with a CD4 > 22% at study initiation. Before HAART all children had moderately to severely suppressed immune function by CDC criteria (CD4 < 25%) or CDC Category B or C disease. Cohort 2 (C2) included children with no current or past evidence of immunosuppression based on CDC criteria (CD4 > 25%) and no evidence of clinical disease. Children in C2 were receiving a non-HAART regimen. Methods. Immunophenotyping was performed to characterize CD4+ and CD8(+) subsets with regard to maturation and activation. T cell rearrangement excision circles (TRECs) were measured to quantify recent thymic emigrants. Results. No difference was found in percent CD4(+) or percent CD8(+) T cells or maturation markers between C1 and C2. There was significantly less expression of activation markers in both CD4(+) and CD8(+) cells in C1. There was no difference in TREC production between C1 and C2. Conclusion. Moderately to severely suppressed HIV-1-infected children receiving HAART are able to reconstitute their immune systems to a degree that is indistinguishable from that of stable, CDC Class A1 HIV-1-infected children with regard to CD4(+) and CD8(+) T cell subsets, expression of cellular maturation markers and TREC production.