HIV Last Longer In The Body Than Scientists Thought
The reservoir of HIV in people successfully treating the virus dissipates at a much slower rate than previously thought, according to a new study.
These reservoirs are resistant to antiretroviral drugs and host immune systems, leading to a resurgence of the virus if treatment is paused or stopped altogether.
Researchers with the National AIDS Treatment Advocacy Project (NATAP) tracked 111 people with an undetectable viral load for an average of eight years, to see how much of the virus was still in their system.
The HIV reservoir half-life in these subjects averaged 12 years (144 months) for those with detectable viral loads, more than twice previously assumed. In people who were never detectable, though, that period was 64 months. For patients with viral "blips"—temporary elevations of viral load to a quantifiable levels—that half-life rose to 204 months.
Previously, investigators reported reservoir half-lives averaging 70 months in people with acute HIV infection, 96 months in those with chronic infection, and between 6.3 months and 44 months in those whose viral load was undetectable.
The size of the HIV reservoir, say NATAP researchers, is "a critical factor" in determining if an HIV-eradication strategy is working and, potentially, how long it must be employed.
Writes POZ:
The persistence of the viral reservoir frustrates efforts to cure HIV. A main component of the reservoir is long-lived immune cells that are latently infected with the virus. A latently infected cell is not replicating. And because standard antiretroviral (ARV) treatment works against the virus only when a cell is replicating, latently infected cells stay under the radar of ARVs and may start replicating again, perhaps after years.
If someone is still being treated for the virus at this time, ARVs could suppress such viral production. But if an individual were off ARVs, such newly replicating cells could lead to a viral rebound, in which viral load shoots back up again.
The researchers attributed the difference in results to several factors including a larger pool of participants and more precise testing methods.
The findings were presented at the IDWeek 2016 conference in October in New Orleans.