NEW YORK (Reuters Health) – HIV-positive individuals have lower neuropsychological test scores and smaller brain volumes than HIV-negative people, but the disadvantages do not worsen in patients who receive combination antiretroviral therapy (cART), researchers report.
“With HIV treatment (cART) widely available, more and more HIV-positive individuals are well-treated with good viral suppression,” Ryan Sanford from McGill University, Montreal, Canada, told Reuters Health by email. “This makes our results interesting, because it suggests that treatment and maintaining undetectable viral loads may prevent progressive brain atrophy.”
HIV-associated neurocognitive disorders affect as many as 40% of HIV-positive individuals despite effective viral suppression.
To assess whether effective viral suppression can mitigate the progression of brain atrophy, Sanford’s team used structural MRI and neuropsychological assessments to compare changes over approximately 2 years among 48 HIV-positive and 31 HIV-negative individuals.
All HIV-positive participants were receiving stable cART and had undetectable viral loads at baseline and at follow-up.
At baseline, HIV-positive participants had lower neuropsychological scores compared with HIV-negative participants for all but two of eight standard tests, after adjustment for age, sex, and educational level, according to the November 13 JAMA Neurology online report.
Both groups showed few and similar changes in neuropsychological test scores at follow-up. Among HIV-positive participants, neuropsychological scores did not correlate with current or nadir CD4-cell count or with duration of infection.
Cortical thickness and subcortical volumes were smaller at baseline in the HIV-positive group than the controls, but changes in brain volumes over time were similar between the groups.
Lower nadir CD4-cell count significantly correlated with reduced white-matter volumes and smaller brain volumes in the putamen, globus pallidus, and thalamus, but not with cortical thickness estimates.
“Taken together, our results could support the hypothesis that neurobiological changes occurring early in infection may be responsible for the cognitive impairment found in chronic HIV-positive individuals,” the researchers note. “This finding suggests that early initiation of cART may have neurocognitive benefits. However, future longitudinal work assessing brain structure and function in primary HIV infection is required to verify this hypothesis.”
“Our results send the hopeful message that adhering to treatment and maintaining viral suppression may protect the brain from further injury,” Sanford said.
He cautioned, “The HIV-positive participants did not have any comorbid conditions (i.e., major psychiatric disorder, active substance abuse, or other neurological disorders), limiting the generalizability to HIV-positive individuals with similar characteristics. Indeed, HIV-positive individuals with some comorbid condition may be more likely to experience progressive brain atrophy.”
SOURCE: http://bit.ly/2zE1zgz
JAMA Neurol 2017.
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