ATLANTA (CBS ATLANTA) — New research finds that the pool of people with HIV silently lingering in their body may be up to 60 times larger than previous estimates.
The Howard Hughes Medical Institute findings show that current efforts to eradicate HIV may be ineffective if such tactics do not target inactive viruses in people. The virus continues to be a threat, even while inactive, because it retains the ability to become active even following treatment from the most effective HIV drugs on the market.
The study results, published in the Oct. 24 edition of the journal Cell, is troubling for those working to fight the virus.
“The findings suggest that there are a lot more of these proviruses that we have to worry about than we thought,” says Robert F. Siliciano, an HHMI investigator at The Johns Hopkins University who led the new study, in a press release from HHMI. “It doesn’t mean that it’s hopeless, but it does mean we need to focus on getting an even clearer idea of the scope of the problem.”
“For people that are working on HIV, figuring out the size of the reservoir has been a really critical issue,” says Siliciano. “The field has struggled with what you even measure in people who are participating in eradication studies. How do you know how much virus is left?”
The HIV infection target’s the human immune system’s T-cells – with instructions to turn those cells against the body.
For some, the virus remains latent – the virus is present in the cells but is not reproducing new viruses in the body. Researchers have not yet found how to eliminate inactive viruses.
The HHMI research found that 12 percent of T-cells studied contained fully intact viral genomes that could be activated in the future, but were not currently functioning to create viruses.
When the researchers calculated the size of the viral reservoir by factoring in the 12 percent of non-induced proviruses that have the ability to become active they found the pool may be as much as 60 times larger than previous estimates.
“This is a huge increase in the barrier to curing this disease.” Even if a patient is successfully treated with antiretroviral drugs that stop all active HIV replication, the silent viruses could activate to cause disease at any point after antiretroviral therapy is stopped. Drugs targeting the inactive viruses are required to lead to a complete cure, or remission, of HIV, Siliciano says.
HHMI is a Maryland-based science philanthropy that invested $695 million toward research in 2012.