Some 30 researchers from the University of California-San Francisco and the Gladstone Institute of Virology and Immunology have come together to investigate why HIV-positive patients, who are now living longer lives thanks to anti-retroviral drugs, seem to be aging faster than their uninfected peers.
"There's a long list of concerns that people have raised about the effects of chronic HIV infection on different health outcomes," says Dr. Paul Volberding, who as a co-chair of San Francisco's Center for AIDS Research is bringing together this group of scientists. UCSF/San Francisco General Hospital cardiologist Priscilla Hsue, for example, has found that HIV-positive patients (the patients she sees in San Francisco are mostly men) have heart attacks when they're around 50 years old. That's 10 years earlier than when your average, uninfected, man has a heart attack.
Other researchers have found that HIV-infected patients develop dementia younger and kidney failure at a faster rate than their uninfected peers. Volberding says that these patients are also showing accelerated bone loss and accelerated loss of their kidney function. These are all ways in which our bodies normally decline as we age. But in patients with HIV, the decline seems to be faster.
At the beginning, researchers believed that anti-retroviral drugs were causing the aging, but as research has progressed, the thinking has shifted. "The more nuanced recognition now is that maybe some of that was from the drugs," says Volberding, "but maybe some of it was because the drugs were working and patients were living longer and allowing us to see these other effects of chronic viral infection." Even though anti-retroviral drugs can bring the amount of virus in the body down to almost undetectable levels, there is always a tiny amount of HIV replicating inside a patient's body. And Volberding and others believe that this virus could be responsible for the sped-up aging.
UCSF molecular biologist Elizabeth Blackburn, another member of this new group, has spent her life studying the tips of our chromosomes, called our telomeres (pronounced TEAL-oh-meres), and the role they play in aging. Blackburn has found that as we age, our telomeres wear away and shorten. She has studied the telomeres in patients with heart disease and cancer, and now she wants to look at HIV patients' telomeres.
