HIV and age underlie specific patterns of brain abnormalities and cognitive changes in high functioning patients

Area of Science:

• Neuroscience
• Immunology
• Radiology

Background:

• Brain structure and cognitive function in individuals with human immunodeficiency virus (HIV) on combination antiretroviral therapy (cART) are not fully understood, especially when other comorbidities are absent.
• Previous research on the effects of HIV and aging on the brain has yielded conflicting results.

Purpose of the Study:

• To investigate the impact of HIV status and age on brain structure and cognitive performance.
• To utilize machine learning to identify distinguishing brain and cognitive features between aviremic HIV-positive individuals on cART and healthy controls.

Main Methods:

• Neuropsychological testing and volumetric magnetic resonance imaging (MRI) were performed on 53 HIV-positive patients and 62 healthy controls.
• Voxel-based morphometry, ANCOVAs, machine learning, and multivariate regression were employed to analyze structural brain and neurocognitive data.

Main Results:

• HIV-positive individuals exhibited smaller volumes and gray matter thickness in the caudate, parahippocampus, insula, and inferior frontal gyrus compared to healthy controls.
• HIV-positive subjects performed worse on complex attention and cognitive fluency tasks.
• Machine learning identified cognitive scores (complex attention, psychomotor speed) and brain volumetric measures (white matter, gray matter, ventricles, amygdala, caudate, putamen) as key discriminators between groups.
• Both voxel-based morphometry and regression analyses indicated that HIV and aging independently exacerbate brain vulnerability and cognitive impairment.

Conclusions:

• Effective cART in HIV patients is associated with reduced brain volume and cognitive function compared to seronegative individuals.
• No significant interaction was found between HIV infection and aging on brain structure or cognitive function.