A team of researchers has discovered HIV can begin replicating in the brain as early as four months after initial infection. The study followed 72 treatment naïve participants during the first two years of HIV infection. Through analysis of cerebral spinal fluid (CSF) and blood samples, 20 percent of subjects showed replication in the central nervous system (CNS) at four months. Additionally, 30 percent of participants showed evidence of a marked CSF inflammatory response in at least one time point and 16 percent of study volunteers showed a marked CSF inflammatory response at multiple time points, suggesting an ongoing infection in the CNS. The findings will be published in the scientific journal PLoS Pathogens.
“This shows that viral replication and inflammation can occur early in infection with the concern being that the damage caused could be irreversible,” says study virologist Ronald Swanstrom, PhD, Director of the University of North Carolina’s Center for AIDS Research (CFAR) and Professor of Biochemistry and Biophysics at UNC’s School of Medicine. “HIV and inflammation have the potential to accelerate the aging process and cause neurocognitive impairment, in the extreme case resulting in HIV-associated dementia.”
One-third of people not taking antiretroviral therapy (ART) to control their HIV will eventually develop HIV-associated dementia, Swanstrom says. For him, the study’s results in these newly infected people stress the importance of routine HIV testing to catch the infection as early as possible to allow the prompt initiation antiretroviral therapy.
“This is yet another reason we want people on ART right away to limit the possibility of replication and inflammation in the brain,” Swanstrom says.
Future studies could focus on whether or not damage to the brain caused by this early replication and inflammation is reversible. Swanstrom collaborated on the study with senior author and neurologist Serena Spudich, MD, Division Chief of Neurological Infections & Global Neurology and Associate Professor of Neurology at Yale School of Medicine, and neurologist Richard Price, MD, Professor of Neurology at the University of California San Francisco School of Medicine. The first author on the study was a UNC graduate student in the Department of Microbiology and Immunology, Christa Sturdevant, who is now a postdoctoral fellow at Duke University. The study was funded by the National Institute of Mental Health.