Two men with HIV who received bone marrow transplants in Boston appear to have no detectable levels of the virus in their bodies, and were able to stop taking medication for the condition, researchers say.
One patient has been off HIV medication for seven weeks, and one for 15 weeks, and neither showed signs of the virus returning, according to the New York Times.
The patients are not considered cured of HIV because there's still the possibility that the virus may be hiding somewhere (in a tissue not tested by the researchers), and that the virus may return.
The bone marrow transplants were performed because both patients had blood cancer, so the findings don't apply to most patients with HIV. Patients without blood cancer cannot have the treatment because it is risky, and carries a 15 to 20 percent risk of death, the Times said.
Cells from bone marrow give rise to immune cells, the very cells that are infected with HIV. The Boston patients kept taking antiretroviral drugs after their transplants so that their "new" immune cells would not be infected with HIV. It's also thought that the patients' new immune cells attacked and destroyed the "old" immune cells infected with HIV.
The finding may provide AIDS researchers with new clues regarding how the body's own immune system can be leveraged to attack HIV.
The cases are similar to that of the "Berlin patient" who has been HIV-free for five years following a bone marrow transplant. However, the Berlin patient received bone marrow donated from a person with a special mutation that made the immune cells resistant to HIV. The bone marrow donors for the two Boston patients did not have this mutation.