HIV returns in American men after bone marrow transplants
Signs of HIV have returned in two American men who appeared to have briefly eradicated the virus after bone marrow transplants for cancer, US doctors said.
Experts said the discovery is a disappointment to efforts to find a cure for the virus behind AIDS, but offers important new clues in the hunt for the disease's hiding places.
Only one person is believed to have been cured of HIV. American Timothy Brown, who suffered from leukemia, received a bone marrow transplant from a rare donor resistant to HIV and has shown no sign of the virus for six years.
"The return of detectible levels of HIV in our patients is disappointing, but scientifically significant," said Timothy Heinrich, a physician-researcher in the Division of Infectious Diseases at Brigham and Women's Hospital in Boston.
"Through this research we have discovered the HIV reservoir is deeper and more persistent than previously known."
Both HIV-positive men received bone marrow transplants as treatment for Hodgkin's lymphoma in 2008 and 2010.
About eight months after their operations, HIV was no longer detectable so the patients ceased taking antiretroviral drugs.
In July, doctors announced that the patients appeared HIV-free after being off the drugs for several weeks.
But signs of HIV soon returned. They were found in the first patient 12 weeks after stopping therapy, and in the second patient after 32 weeks.