Extremely low viral reservoir in treated chronically HIV-1-infected individuals.

Background: Small viral reservoirs are found predominantly in HIV-1 controllers and individuals treated during acute/early HIV-1 infection. However, other HIV+ individuals could naturally also harbour low viral reservoirs.

Methods: We screened 451 HIV-1-infected treated-individuals with suppressed plasma viremia for at least 3 years and stored cryopreserved peripheral blood mononuclear cells (PBMCs). Total HIV-DNA was analysed in PBMCs with ddPCR. Individuals with 50 HIV-DNA copies/106 PBMCs constitute the ‘Low Viral Reservoir Treated’ cohort (LoViReT). Longitudinal samples were obtained from 12 chronically treated LoViReT and compared to 13 controls (>50 HIV-DNA copies/106 PBMCs) to analyse total HIV-DNA, T-cell and NK-cell populations, HIV-1 specific antibodies, and plasma inflammation markers.

Results: We found that 9.3% of the individuals screened had 50 HIV-DNA copies/106 PBMCs. At least 66% initiated cART during the chronic phase of HIV-1 infection (cp-LoViReT). Cp-LoViReT harboured lower levels of HIV-DNA before cART and after treatment introduction the decays were greater compared to controls. They displayed a marked decline in quantity and avidity in HIV-specific antibodies after initiation of cART. Cp-LoViReT had fewer CD8+ TTM and TEMRA in the absence of cART, and higher CD8+ TN after 18 months on therapy.

Conclusion: We found that 9.3% of the individuals screened had 50 HIV-DNA copies/106 PBMCs. At least 66% initiated cART during the chronic phase of HIV-1 infection (cp-LoViReT). Cp-LoViReT harboured lower levels of HIV-DNA before cART and after treatment introduction the decays were greater compared to controls. They displayed a marked decline in quantity and avidity in HIV-specific antibodies after initiation of cART. Cp-LoViReT had fewer CD8+ TTM and TEMRA in the absence of cART, and higher CD8+ TN after 18 months on therapy.