HIV-DNA content in pTfh cells is associated with residual viremia in elite controllers.

Objective: The source of residual HIV viremia is highly debated and its potential relationship with the HIV reservoir has not been clarified. Herein, we analysed the cell-associated HIV-DNA content in two important cell compartments of the HIV reservoir, resting CD4+ T memory (Trm) and peripheral T follicular helper (pTfh) cells, and the association with the residual HIV viremia in individuals with spontaneous HIV replication control (elite controllers, EC group) and in individuals with antiretroviral therapy (ART)-mediated HIV replication control (cART group).

Design: A cross-sectional study.

Methods: Seventeen chronically HIV-infected patients with suppressed HIV replication were included. Cell-associated HIV-DNA was measured by ultrasensitive digital-droplet-PCR in purified Trm and pTfh cells. Residual HIV plasma viremia was quantified using a single-copy assay with a sensitivity of 0.3 HIV-RNA copies/ml.

Results: A significant and positive correlation was demonstrated between HIV-DNA levels in pTfh cells and residual plasma viral load (rpVL) (rho = 0.928, P = 0.008) in HIV-positive elite controllers, but not in HIV-positive treated patients, despite the lower levels of cell-associated HIV-DNA found in elite controllers compared with cART patients in pTfh cells [176 (77-882) vs. 608 (361-860) copies/million cells, respectively; P = 0.05].

Conclusion: This association suggests that pTfh cells could have an important contribution to persistent viremia in elite controllers. This could be the consequence of a more limited control of HIV replication in elite controllers with higher transcriptional activity of HIV in pTfh cells of elite controllers than that in cART patients.