Investigators from the AIDS Clinical Trials Group (ACTG), the world's largest and longest-established HIV research network, today announced that the Journal of Clinical Investigation published new findings from the ACTG HIV Reservoirs Cohort Study (A5321). The study found that HIV DNA remained in the cerebrospinal fluid of half of participants with well-managed HIV (virologic suppression in the plasma), confirming that the central nervous system (CNS) is a major reservoir for latent HIV. Individuals who harbored HIV DNA in the cerebrospinal fluid were more likely than other study participants to experience cognitive deficits on neurocognitive testing.
The persistence of HIV in sanctuary sites in the human body, even in the presence of long-term therapy, is a challenge to HIV remission and cure that the ACTG is actively working to address. Because neurocognitive function can be compromised even in individuals whose HIV is well treated, it is very important that we understand HIV persistence in the CNS so that we can develop strategies to treat it. This study provides preliminary insights into these challenges."
Judith Currier, M.D., MSc, ACTG Chair, University of California Los Angeles
This substudy in the ACTG HIV Reservoirs Cohort Study (A5321) was led by Serena Spudich, M.D., Yale University, the late Kevin Robertson, Ph.D., University of North Carolina at Chapel Hill, and John Mellors, M.D., University of Pittsburgh. The study included 69 participants with well-treated HIV who had their cerebrospinal fluid and blood collected and underwent neurocognitive assessments, which included tests of memory, learning, motor function, and more. Participants were mostly male (97 percent) and had been on HIV treatment for a median of almost nine years, with a good response to medications (HIV viral loads in the plasma were all <100 copies/mL and median CD4 counts were in the normal range). Using highly sensitive methods to detect HIV, researchers found that almost half of these participants harbored viral DNA in cells found in the cerebrospinal fluid. Of those, 30 percent met the criteria for cognitive impairment.
While the study established an association between HIV DNA in cerebrospinal fluid with poorer performance on cognitive tests, researchers stressed that it did not establish a causal relationship, noting that there could be several explanations for the findings. Further studies will help determine strategies to reverse this persistence and improve neurological functioning in individuals with long-standing HIV.