Stem cell treatment puts HIV into long-term remission in landmark study

An international team of scientists is reporting the "functional cure" of an HIV patient for only the second time ever. Known only as "the London patient," the man received a transplant of bone marrow stem cells from a donor that had a resistance to the virus.

The patient has now been in remission for 18 months, with no sign of the HIV-1 virus in his bloodstream. But as exciting as the news is, there are a few caveats.

The research was conducted by scientists at the University of Melbourne, the Westmead Institute for Medical Research, and the University of Cambridge. The London patient was diagnosed with HIV in 2003, and then advanced Hodgkin's lymphoma in 2012. To treat that cancer, he received bone marrow stem cells from a donor who had two copies of a particular mutation to the gene CCR5, which makes them more HIV-resistant.

Antiretroviral therapy (ART) is a common method of managing HIV infection, but 16 months after the transplant, the patient was successfully taken off that treatment. It's now been a further 18 months since stopping ART, and levels of HIV-1 RNA and DNA are still so low as to be undetectable. That means the London patient is in remission and appears to be effectively cured, although the research team is reluctant to jump to that conclusion too early.

This is only the second recorded time a patient has gone into HIV remission. The first case occurred in 2007, when "the Berlin patient," later identified as American man Timothy Brown, underwent a similar, albeit more aggressive, treatment.