Sydney:
In a piece of good news after the sad announcement a few days ago about HIV virus rebounding in the "Mississippi Baby", scientists have uncovered two new cases of HIV patients in whom the virus has become undetectable.
The two Australian men became apparently HIV-free after receiving stem cells to treat cancer, the scientific journal Nature reported.
"They are still on anti-retroviral therapy (ART) 'as a precaution' but those drugs alone could not be responsible for bringing the virus to such low levels," said David Cooper, director of the Kirby Institute at University of New South Wales in Sydney.
Cooper and his team scanned the archives of St Vincent's hospital in Sydney - one of the largest bone-marrow centres in Australia - and found these two patients.
The first patient had received a bone-marrow transplant for non-Hodgkin's lymphoma in 2011.
The other had been treated for leukemia in 2012.
Because of the risk of relapse, Cooper's team will not claim that their patients are completely cured.
According to Cooper, the results show that "there is something about bone-marrow transplantation in people with HIV that has an anti-HIV reservoir effect, such that the reservoirs go down to very low levels".
If we can understand what is that and how that happens, it will really accelerate the field of cure search, Cooper added.
At the moment, there is only one person in the world who is still considered cured of HIV - Timothy Ray Brown.
This "Berlin patient" received a bone-marrow transplant and has had no signs of the virus in his blood for six years without ART.
Stem-cell transplant in itself cannot be used as a routine HIV treatment because of the high mortality (10 percent) associated with the procedure, the Nature report added.