WEDNESDAY, April 17, 2024 In a new study, people living with HIV who got standard meds to keep the virus at bay also had much lower rates of Alzheimer's disease -- suggesting the drugs might also lower risks for the brain illness.

It's early-stage research, but it's possible that mechanisms used by these HIV drugs work at a genetic level to thwart Alzheimer's in the brain, concluded a team led by Dr. Jerold Chun. He's a professor in the degenerative disease program at the nonprofit research group Sanford Burnham Prebys, in La Jolla, Calif.

In the study, Chun's group looked at rates of Alzheimer's disease among nearly 80,000 HIV-positive individuals over the age of 60. More than 46,000 of them had been prescribed a form of HIV-suppressing medications known as reverse transcriptase (RT) inhibitors.

Among this subgroup, Alzheimer's diagnoses occurred in about 2.5 people per 1,000 -- much less frequently than the 6.15 per 1,000 observed in a control group of older people without HIV, the researchers found.

The study wasn't designed to prove that RT inhibitors directly prevent Alzheimer's disease. However, the finding was intriguing and there are genetic mechanisms that might explain the link, the scientists said.

In findings first published in the journal Nature in 2018, Chun's lab showed that, in Alzheimer's patients, a gene found in neurons undergoes mutations that can produce thousands of new gene variants.

The Alzheimer's-linked gene, called APP, undergoes this transformation using the same enzyme -- reverse transcriptase -- that HIV uses to genetically hijack human cells.

That's why RT inhibitor drugs are a common ingredient in the drug "cocktail" that HIV-positive people use to suppress the virus.

So, it stands to reason that RT inhibitors might also thwart RT processes involved in Alzheimer's disease within brain cells, Chun's team theorized.

Their work, published recently in the journal Pharmaceuticals, was funded by the U.S. National Institute on Aging.

In a news release from Sanford Burnham Prebys, Chun stressed that the research is still in its early days.

“What we’re looking at now is very crude,” said Chun, who is also senior vice president for neuroscience drug discovery at the organization. “The clear next step for our lab is to identify which versions of RTs are at work in the AD [Alzheimer's disease] brain, so that more targeted treatments can be discovered, while prospective clinical trials of currently available RT inhibitors on persons with early AD should be pursued.”

More information

Find out more about how HIV works at the U.S. National Institutes of Health.

SOURCE: Sanford Burnham Prebys, news release, April 16, 2024