Initiation of antiretroviral therapy differentially influences genital and systemic immune activation in HIV-infected women.

Antiretroviral therapy (ART) has significantly improved the quality of life of HIV-infected individuals: reducing plasma viremia, restoring CD4+ T-cell numbers and correcting imbalances in blood memory T-cell subsets. While ART improves immune correlates at mucosal sites, including the lower female genital tract (FGT), ART initiation has been associated with reactivation of common FGT infections. We investigated the effect of ART on immune activation and inflammation in the genital tract. We measured blood and genital T-cell activation, proliferation, and immunosenescence (CD38, HLADR, Ki67, CD127 and CD57) and cytokine levels in women on ART for ~7 years (cross-sectional analysis) or initiating ART (immediately before and one month after). Effector memory T-cells predominated in blood and FGT during chronic infection, irrespective of ART status. In women initiating ART, one month was insufficient for T-cell reconstitution, or alterations in T-cell subset distribution, despite both plasma and genital viral loads decreasing to undetectable levels in most participants. Initiating ART was accompanied by a decline in plasma IP-10 that correlated with decreased blood CD38 expression in blood (p=0.0204) but not in the FGT. The reduction in plasma (but not genital) cytokine levels due to ART initiation was dependent on their concentrations before treatment. While T-cell activation decreased significantly in blood (CD4: p=0.0.032; CD8: p=0.0137), activation levels remained similar in the genital tract despite one month of treatment. Overall, the decrease in cellular activation and inflammation seen in blood with ART initiation was not evident in the FGT.