T-cell re-population in HIV-infected children on highly active anti-retroviral therapy (HAART)

In this pilot study, we address the nature of the re-population of the T-ce ll compartment in HIV-1(+) (Human Immunodeficiency Virus 1), vertically inf ected children placed on successful regimens of HAART (highly active anti-r etroviral therapy) incorporating 2 NRTI and a protease inhibitor. The clona lity of the T-cell compartment and the abundance of RTEs (Recent Thymic Emi grants) were determined 2 weeks before and 20 weeks after initiation of HAA RT in a subgroup of children taking part in the PENTA (Paediatric European Network for the Treatment of AIDS) 5 trial. Analysis of the clonality of th e circulating T-cell compartment was assessed using CDR3 spectratyping and analysed using the Kolmogorov-Smirnov two sample test. This revealed that a high degree of T-cell clonal restriction still exists 5 months into therap y, despite the appearance of previously undetectable T-cell clones within t he periphery. We detected no increase in RTE abundance in this 5 month peri od, as determined by PCR detection of TRECs (T-Cell Receptor Excision Circl es). We conclude that the observed re-population of T cells within the peri phery of treated children is heavily reliant upon the maintenance/expansion of pre-existing cells during the 5 month period immediately following the initiation of therapy.