Study: Combination Antiretroviral Therapy Prevents Cognitive Decline
Maintaining an undetectable viral load through effective combination antiretroviral therapy (cART) can prevent cognitive decline and progressive neurological deterioration in people living with HIV, according to a recent study.
The study, conducted among 92 HIV-positive individuals and 55 HIV-negative control participants living in St. Louis, Missouri, used magnetic resonance imaging (MRI) to measure brain volume in addition to a series of neuropsychological tests to measure changes in cognitive function over a two-year period.
During this time, scientists did not find significant declines in either brain volume or cognitive function in HIV-positive individuals with undetectable viral loads compared to HIV-negative controls. All people living with HIV in the study were receiving stable cART.
Previous studies have shown that individuals with unstable viral suppression undergo progressive neurological decline, study authors noted. HIV-associated neurocognitive disorders are most often asymptomatic and affect up to 40% of those with effective viral suppression. The new study, while confirming that HIV infection is associated with slightly lower volume in several brain regions, shows that early initiation of cART may minimize neurological deterioration in people living with HIV.
We are beginning to understand the biological mechanisms underlying neurological changes that occur during HIV infection. Certain toxic proteins found in the virus promote inflammation of the nervous system, which may result in permanent neurological damage. Although cART prevents further damage in people living with HIV, it does not appear capable of repairing existing damage that occurred during untreated infection. These results provide further justification for beginning – and maintaining – HIV treatment as soon as possible following infection.
The findings were published online in JAMA Neurology in November by Ryan Sanford and colleagues at the Montreal Neurological Institute of McGill University. Sanford emphasized that these results come as good news for people living with HIV.
“This is encouraging because it sends a hopeful message to people living with HIV that cognitive impairment may be avoidable with treatment,” said Sanford.
In addition to being well-treated and virologically suppressed, study participants also had little to no comorbid conditions (e.g. depression, drug use, cardiovascular risk). Since cardiovascular risk factors like high cholesterol have been linked to cognitive decline even in well-treated individuals, more research is crucial to “disentangle” other potential causes of cognitive impairment in people living with HIV, added Sanford.
Future studies are needed to determine whether subtle changes in cognitive function begin to manifest after longer periods of infection. Study authors added that focusing on cognitive function in older HIV-positive adults, furthermore, could determine whether increasing age and HIV infection have synergistic effects on long-term brain health.