Antiretroviral medicines have helped millions of people with HIV (human immunodeficiency virus) live longer, healthier lives, but new research found that even after nearly a decade of strict HIV treatment, cells sheltering the virus could be found in the cerebrospinal fluid—a clear, colorless fluid found in the brain and spinal cord—in half of study participants living with HIV. In addition, researchers found that people with HIV in their cerebrospinal fluid were more likely to have cognitive impairments such as problems with memory, concentration and the ability to complete complex tasks.
Researchers from the University of Pittsburgh, along with other sites around the country, examined cerebrospinal fluid from 69 people with HIV who had been on anti-HIV therapy for an average of nine years. Very sensitive methods of detecting HIV revealed that 48% of the participants harbored viral DNA in cells found in the cerebrospinal fluid. Of those, 30% met criteria for cognitive impairment, compared with 11% of those who did not have cells with HIV in their cerebrospinal fluid.
Although the study may help answer questions about why people with well-controlled HIV still experience cognitive problems, researchers cautioned that these results do not prove that the presence of these cells in the cerebrospinal fluid causes the cognitive impairment and that there could be several explanations for the findings. For instance, it is possible that the level of original infection in the nervous system was higher in the group with the cells harboring HIV or that the development of cognitive problems may have been set in motion early in the HIV infection, before the anti-HIV therapy was started.
The authors noted that future clinical trials will be needed both to establish a reason that a cerebrospinal HIV reservoir would be linked to cognitive decline, to determine if eliminating this reservoir is possible, and if doing so improves cognitive function in people living with HIV. In the meantime, senior author John Mellors, MD, notes that although treatment is not yet available to clear HIV from cerebrospinal cells, awareness of the potential link between HIV infection, even when well-controlled, and cognitive issues can help physicians to track patients who may need additional monitoring.
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