Researchers based at the University of Cambridge in the United Kingdom said on Tuesday, in an article published by the prestigious scientific journal Nature, that for only the second time in the 38-year history of the HIV epidemic, a patient has been completely cleared of the virus.
But the researchers warned that though the patient, whose name was not released, has not taken antiviral drugs for 18 months with no sign of the HIV virus resurfacing in his system, it remains too early to describe the patient as “cured.”
Nonetheless, the result repeats a similar study on a patient in Germany more than a decade ago, and opens up the possibility for a full HIV cure—even if scientists say they are not there yet, calling the result a “long term remission” rather than a “cure.”
“This will inspire people that cure is not a dream,” Dr. Annemarie Wensing, a prominent Dutch virologist, told The New York Times. “It’s reachable.”
The new patient is being referred to as “the London patient,” while the first successful recipient of the treatment has been called “the Berlin patient.”
Researchers obtained the result using stem cell therapy, with cells taken from the bone marrow of a donor who was resistant to HIV infection due to a genetic mutation. The donor “had two copies of a mutation in the CCR5 gene, which gives people resistance to HIV infection. This gene codes for a receptor which sits on the surface of white blood cells involved in the body’s immune response,” Nature reported, in a news story about the findings published in the March 5 issue of the journal's print edition.
In HIV infections, the virus “binds” to the receptors on the cell surface. But the CCR5 mutation causes the receptor to reject the HIV virus, which becomes unable to attach itself to the cell and attack it, Nature explained. People with two copies of the mutated gene are naturally resistant to HIV infection.
But the double-copied mutation occurs in only one percent of people of European descent, according to Nature.
In addition, the bone marrow transplant necessary to implant the stem cells carries severe risks that make it an unrealistic treatment for patients who do not already have cancer. Scientists say that the antiviral drugs currently used to control HIV remain a better option for most patients.
“If you’re well, the risk of having a bone-marrow transplant is far greater than the risk of staying on tablets every day,” Imperial College of London researcher Graham Cooke told Nature.
Photo by C. Goldsmith, Centers for Disease Control and Prevention/ Wikimedia Commons Public Domain
