A team of international scientists led by Northwestern University found that HIV is still replicating in lymphoid tissue, even when it is undetectable in the blood of patients on antiretroviral drugs.
The findings provide a critical new perspective on how HIV persists in the body despite potent antiretroviral therapy.
“We now have a path to a cure,” said corresponding author Dr. Steven Wolinsky, chief of infectious diseases in the department of medicine. “The challenge is to deliver drugs at clinically effective concentrations to where the virus continues to replicate within the patient.”
The paper was published in Nature.
Combinations of potent antiretroviral drugs quickly suppress HIV to undetectable levels in the bloodstream of most patients, but HIV persists in a viral reservoir within lymphoid tissue in the body. The virus rapidly rebounds in the blood if patients stop their drugs. This suggests that long-lived latently infected cells and/or ongoing low levels of HIV replication maintain these viral reservoirs.
The findings provide a new perspective on how HIV persists in the body despite potent antiretroviral therapy. The study also explains why the development of drug resistance is not inevitable when virus growth occurs in a place where drug concentrations are very low.
Most importantly, this new understanding highlights how important it is to deliver high concentrations of antiretroviral drugs to all locations in the body where HIV can grow. Drugs that penetrate the newly discovered sanctuaries will be a prerequisite to the elimination of the viral reservoir and, ultimately, a step towards a cure.