It is possible that antiretroviral (ARV) treatment of HIV may combat the apparent effect the virus has on brain aging and associated cognitive decline.

Researchers in the ongoing COBRA study in academic centers in London and Amsterdam recruited 134 HIV-positive participants on successful ARV treatment with an average age of 57.4 and closely matched them with a control group of 79 HIV-negative individuals. (A respective 120 and 76 of them completed follow-up.) They presented interim findings about the results of two years of cutting-edge MRI-based tests and neuropyschometric testing at the 2017 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.

The COBRA study is in line with another presented at CROI that found that HIV is associated with brain injury. In the case of this study, this meant smaller gray matter, abnormal white matter microstructure and the finding that the participants living with HIV had worse cognitive performance compared with their peers who did not have virus. Because the other study did not follow participants over time as COBRA did, it could not, however, determine how brain injury might progress among people with HIV, in particular those on fully suppressive ARV treatment.

During the two years of follow-up, the COBRA researchers did not see any excess decline in any of the measures of brain injury or cognitive function among the HIV-positive participants compared with the control group. Participants in both groups experienced about a 1 percent annual decline in brain volume.