Accelerated aging occurs shortly after infection, study finds

Living with HIV can have an immediate effect on the way your body ages, according to new research which has shown that cellular aging is accelerated in male patients within two to three years of infection.

Researchers at the University of California, Los Angeles (UCLA) looked at blood samples from more than 200 men to compare those with HIV infection to a control group that didn’t have HIV, and scored them out of five. different measures of aging.

The study, published Thursday in the journal iScience, found that people living with HIV showed 2 to 5 years of aging compared to their uninfected counterparts within three years of infection.

“Our work demonstrates that even in the first months and years of living with HIV, the virus has already triggered an accelerated aging process at the DNA level,” Elizabeth Crabb Breen, professor emeritus at the Cousins ​​Center for Psychoneuroimmunology from UCLA and lead author of the study, said in a press release. “This underscores the critical importance of early diagnosis of HIV and an awareness of issues related to aging, as well as the value of preventing HIV infection in the first place.”

HIV is a virus that attacks the body’s immune system, leaving the patient vulnerable to serious, even mild, illnesses or medical problems. At an advanced stage, this can lead to AIDS, in which the immune system is severely damaged. There is no cure for HIV, but those living with HIV can safely manage it and avoid passing it on with current treatments.

According to 2018 data, approximately 62,000 people in Canada are living with HIV.

Scientists have previously speculated that HIV and antiretroviral therapies that keep the infection under control could contribute to this accelerated aging, but this is one of the first studies to directly compare infected and uninfected people. to look into this issue, according to the statement. .

The researchers used data from the Multicenter AIDS Cohort Study, an ongoing study that began in 1984.

They examined blood samples taken from 102 patients before they were infected with HIV and then two to three years after infection, and matched these patients to samples taken from 102 men of the same age over the course of the same period.

But how can blood show your aging? By looking at the matter at a subcellular level.

The researchers used the lens of epigenetics, which is the study of how your environment and behaviors change how your genes work – for example, whether your body will follow genetic instructions to create a specific protein, or whether epigenetic changes will have turned this gene “off”.

Some epigenetic changes are reversible, and some are progressive, like how aging affects the expression of our genes.

By examining how HIV affects DNA methylation, a type of epigenetic change that turns genes off and prevents them from reading instructions to create certain proteins, the researchers measured different indicators of aging in the samples.

Four of these are known as “epigenetic clocks” and involve comparing different levels of methylation, lymphocytes or other indicators to an established standard.

The last of five indicators of aging was to look at the length of telomeres, which are the ends of chromosomes that get shorter each time cells divide, until they become so short that cell division is no longer possible. possible – one of many measures of a body’s age, because our bodies steadily age from when we have more dying cells than replicating cells within us.

What the researchers found was that in HIV-positive patients, there was a significant age acceleration in all five measures of aging just before infection and ending two to three years after.

“This clearly demonstrates an early and substantial impact of HIV infection on the epigenetic aging process that begins during the first months and years of life with HIV,” the study says.

“Being infected and living with HIV for only three years or less is already associated with an increased risk of around 20% for a shortened lifespan.”

There was no accelerated aging observed in the uninfected control group during this period.

The associations persisted even after the researchers controlled for other factors in the men’s lives that might contribute to accelerated aging.

“Our access to rare and well-characterized samples allowed us to design this study in a way that leaves little doubt about the role of HIV in obtaining biological signatures of early aging,” said Beth Jamieson, a professor at the division of hematology and oncology at the Geffen School and lead author, said in the release. “Our long-term goal is to determine if we can use any of these signatures to predict whether an individual is at increased risk for specific aging-related disease outcomes, thereby exposing new targets for therapeutic interventions.”

The researchers noted that the study was limited by its small sample size, as well as the fact that it was made up exclusively of men and mainly white men, which means that larger studies need to be carried out. to ensure that these results are applicable at all levels.

Although this is the largest study of its kind, it only followed patients for up to three years after infection.

The researchers say more research needs to be done to determine whether this accelerated aging is sustained throughout a person living with HIV and whether it predicts longer-term clinical outcomes.