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% of subjects showed replication in the central nervous system (CNS) at four months. Additionally, 30% 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.
“This shows that viral replication and inflammation can occur early in infection with the concern being that the damage caused could be irreversible,” said study virologist Dr Ronald Swanstrom, director of the University of North Carolina’s Centre for AIDS Research (CFAR) and professor of biochemistry and biophysics in the UNC School of Medicine. “HIV and inflammation have the potential to accelerate the aging process and cause neuro-cognitive 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 said. 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 of 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 said.
Future studies could focus on whether or not damage to the brain caused by this early replication and inflammation is reversible.