Disrupted brain networks in the aging HIV+ population

Area of Science:

• Neuroscience
• Geriatrics
• Infectious Diseases

Background:

• Antiretroviral therapy has increased lifespan for individuals with human immunodeficiency virus (HIV), integrating them into the aging population.
• Cognitive impairment affects approximately half of the HIV-positive population, but brain network connectivity in these individuals remains understudied.
• Understanding neuropathological alterations in treated HIV+ elders is crucial given their increasing prevalence.

Purpose of the Study:

• To investigate and map white matter connections between cortical regions in HIV-seropositive (HIV+) individuals compared to age-matched controls.
• To determine if HIV infection selectively disrupts the brain's structural network, even with access to antiretroviral therapy.
• To explore the influence of the apolipoprotein E4 (ApoE4) genotype and duration of illness on brain network integrity in HIV+ elders.

Main Methods:

• Combined magnetic resonance imaging-based cortical parcellations with high angular resolution diffusion tensor imaging tractography.
• Analyzed brain structural network connectivity in 55 HIV+ patients and 30 age-matched controls, all aged 60-80 and on antiretroviral therapy.
• Assessed the impact of the ApoE4 genotype and duration of HIV infection on network efficiency.

Main Results:

• HIV+ individuals showed compromised frontal and motor white matter connections compared to controls.
• HIV+ individuals with the ApoE4 genotype exhibited additional network deficits in temporal and parietal connections.
• The ApoE4 genotype interacted with the duration of illness, with longer infection correlating with greater network inefficiencies.

Conclusions:

• Neural network deficiencies in treated HIV+ elders exceed those of normal aging.
• Neuropathological alterations in the brain's structural network are evident in HIV+ individuals, even with effective antiretroviral therapy.
• Network impairments likely contribute to neuropsychological abnormalities observed in elderly HIV patients.