Date Time Researchers Discover How HIV Affects White Matter in Brain Patients infected with HIV experience a loss of white matter in the brain due to the virus, which is associated with cognitive impairment. A new study from researchers at the University of Pennsylvania and Children’s Hospital of Philadelphia (CHOP) discovered the mechanism behind this white matter loss, which could help them understand how to better monitor patients taking antiretroviral therapy (ART) to treat the virus. Previous studies done by this collaborative team have shown that treatment with ART causes white matter loss, but it was difficult for researchers to discern how much of the loss could be attributed to ART compared with the virus itself.