A research paper led by UCL and Imperial College London has reported that a patient treated with stem cell transplant has been in remission from HIV for 18 months and is no longer taking HIV drugs.

The breakthrough, published in Nature journal, suggests that the first case a decade ago was not a one-off and could potentially pave the way for future treatments.

Imperial College reported that both patients were treated with stem cell transplants from donors carrying a genetic mutation that prevents expression of an HIV receptor CCR5. Their white blood cells were replaced with HIV-resistant versions, but the authors say it is still too early to say with certainty that he has been cured of HIV, and will continue to monitor his condition.

The researchers picked a donor who 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.

Normally, the HIV binds to these receptors and attacks the cells, but a deletion in the CCR5 gene stops the receptors from functioning properly, and after the treatment the team found that the virus had completely disappeared from the patient’s blood.

The male London patient was diagnosed with HIV in 2003 and advanced Hodgkin's lymphoma in 2012. He underwent chemotherapy to treat the Hodgkin's cancer and, in addition, stem cells were implanted into the patient from a donor resistant to HIV, leading to both his cancer and HIV going into remission.

The British HIV Association (BHIVA) commented on the development: “Whilst not practical for healthy people living with HIV, this is a promising development in the search for an HIV cure.

"It is too early to say that this second patient’s HIV has been cured as he has been in remission for 18 months. However, the case is important as it reaffirms that the CCR5 receptor is a candidate for future research approaches in HIV remission.”