Background
HIV-1 proviruses persist in people on antiretroviral therapy (ART) but most are defective and do not constitute a replication-competent reservoir. The decay of infected cells carrying intact compared with defective HIV-1 proviruses has not been well-defined in people on ART.
Methods
We separately quantified intact and defective proviruses, residual plasma viremia, and markers of inflammation and activation in people on long-term ART.
Results
Among 40 participants tested longitudinally from a median of 7.1 years to 12 years after ART initiation, intact provirus levels declined significantly over time (median half-life 7.1 years; 95% confidence interval [CI], 3.9, 18), whereas defective provirus levels did not decrease. The median half-life of total HIV-1 DNA was 41.6 years (95% CI, 13.6, 75). The proportion of all proviruses that were intact diminished over time on ART, from about 10% at the first on-ART timepoint to about 5% at the last. Intact provirus levels on ART correlated with total HIV-1 DNA and residual plasma viremia, but there was no evidence for associations between intact provirus levels and inflammation or immune activation.
Conclusions
Cells containing intact, replication-competent proviruses are selectively lost during suppressive ART. Defining the mechanisms involved should inform strategies to accelerate HIV-1 reservoir depletion.
BACKGROUND. Persistence of HIV in sanctuary sites despite antiretroviral therapy (ART) presents a barrier to HIV remission and may affect neurocognitive function. We assessed HIV persistence in cerebrospinal fluid (CSF) and associations with inflammation and neurocognitive performance during long-term ART. METHODS. Participants enrolled in the AIDS Clinical Trials Group (ACTG) HIV Reservoirs Cohort Study (A5321) underwent concurrent lumbar puncture, phlebotomy, and neurocognitive assessment. Cell-associated HIV DNA and HIV RNA (CA-DNA, CA-RNA) were measured by quantitative PCR (qPCR). in peripheral blood mononuclear cells (PBMCs) and in cell pellets from CSF. In CSF supernatant and blood plasma, cell-free HIV RNA was quantified by qPCR with single copy sensitivity, and inflammatory biomarkers were measured by enzyme immunoassay. RESULTS. Sixty-nine participants (97% male, median age 50 years, CD4 696 cells/mm 3 , plasma HIV RNA <100 copies/mL) were assessed after a median 8.6 years of ART. In CSF, cell-free RNA was detected in 4%, CA-RNA in 9%, and CA-DNA in 48% of participants (median level 2.1 copies/10 3 cells). Detection of cell-free CSF HIV RNA was associated with higher plasma HIV RNA (P = 0.007). CSF inflammatory biomarkers did not correlate with HIV persistence measures. Detection of CSF CA-DNA HIV was associated with worse neurocognitive outcomes including global deficit score (P = 0.005), even after adjusting for age and nadir CD4 count. CONCLUSION. HIV-infected cells persist in CSF in almost half of individuals on long-term ART, and their detection is associated with poorer neurocognitive performance.
Fourteen people with HIV-1 on two decades of antiretroviral therapy had longitudinal measurements of intact, defective, and total proviral DNA. Three patterns of intact proviral DNA decay were revealed: 1) biphasic decline with markedly slower second phase decline; 2) initial decline that transitions to a zero-slope plateau; and 3) initial decline followed by later increases in intact proviral DNA. Defective proviral DNA levels were essentially stable. Mechanisms of slowing or reversal of second phase decay of intact proviral DNA may include the inability to clear cells with intact but transcriptionally silent proviruses and clonal expansion of cells with intact proviruses.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.