Progressive brain atrophy in chronically infected and treated HIV+ individuals

Abstract

Growing evidence points to persistent neurological injury in chronic HIV infection. It remains unclear whether chronically HIV-infected individuals on combined antiretroviral therapy (cART) develop progressive brain injury and impaired neurocognitive function despite successful viral suppression and immunological restoration. In a longitudinal neuroimaging study for the HIV Neuroimaging Consortium (HIVNC), we mapped the annual rate of change of regional brain volumes in 155 chronically infected and treated HIV+ participants (mean age 48.0 ± 8.9 yrs; 83.9% Male), using tensor-based morphometry between two time points (mean time interval: 1.0 ± 0.5 yrs). We tested for associations between rates of brain tissue loss and clinical measures of disease severity (nadir or baseline CD4+ cell count and baseline HIV plasma RNA concentration), HIV duration, cART CNS penetration-effectiveness scores, age, as well as change in AIDS Dementia Complex stage. We found significant brain tissue loss across HIV+ participants, including those neuro-asymptomatic with undetectable viral load, largely localized to subcortical regions. Measures of disease severity, age, and neurocognitive decline were associated with greater atrophy. Chronically HIV-infected and treated individuals may undergo progressive brain tissue despite stable and effective cART, which may contribute to neurocognitive decline. Understanding neurological complications of chronic infection, and identifying factors associated with atrophy may help inform strategies to maintain brain health in people living with HIV.