Timeline for HIV replication in the brain identified
News Mar 26, 2015
Study shows that HIV can infect the brain early on and should be combated as soon as possible with antiretroviral therapy to limit risk of dementia
A team of researchers has discovered the human immunodeficieny virus (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 are published in the 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 (UNC) 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.
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Christa Buckheit Sturdevant, Sarah B. Joseph, Gretja Schnell, Richard W. Price, Ronald Swanstrom, Serena Spudich. Compartmentalized Replication of R5 T Cell-Tropic HIV-1 in the Central Nervous System Early in the Course of Infection. PLoS Pathogens, Published March 26 2015. doi: 10.1371/journal.ppat.1004720
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