The case report, published in Nature and carried out by scientists at University College London, Imperial College London, the University of Cambridge and the University of Oxford, comes 10 years after the first such case, known as the ‘Berlin Patient’.
The research was funded by the MRC, Wellcome, the Foundation for AIDS Research, and National Institute for Health Research (NIHR) Biomedical Research Centres at University College London Hospitals, Oxford, Cambridge and Imperial.
The research team is presenting the findings today at the annual Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.
Both patients thus far were treated with stem cell transplants from donors carrying a genetic mutation that prevents expression of an HIV receptor CCR5.
The subject of the new study has been in remission for 18 months after his antiretroviral therapy (ARV) was discontinued. The authors say it is too early to say with certainty that he has been cured of HIV, and will continue to monitor his condition.
Professor Ravindra Gupta, the study’s lead author, said: “At the moment the only way to treat HIV is with medications that suppress the virus, which people need to take for their entire lives, posing a particular challenge in developing countries. Finding a way to eliminate the virus entirely is an urgent global priority, but is particularly difficult because the virus integrates into the white blood cells of its host.”
The report describes a male patient in the UK, who prefers to remain anonymous, and was diagnosed with HIV infection in 2003 and on antiretroviral therapy since 2012.
Later in 2012, he was diagnosed with advanced Hodgkin’s Lymphoma. In addition to chemotherapy, he underwent a haematopoietic stem cell transplant from a donor with two copies of the CCR5 Δ32 allele in 2016.
CCR5 is the most commonly used receptor by HIV-1. People who have two mutated copies of the CCR5 allele are resistant to the HIV-1 virus strain that uses this receptor, as the virus cannot enter host cells.
The patient remained on ARV for 16 months after the transplant, at which point the clinical team and the patient decided to interrupt ARV therapy to test if the patient was truly in HIV-1 remission.
Regular testing confirmed that the patient’s viral load remained undetectable, and he has been in remission for 18 months since ceasing ARV therapy (35 months post-transplant). The patient’s immune cells remain unable to express the CCR5 receptor.
He is only the second person documented to be in sustained remission without ARV. The first, the Berlin Patient, also received a stem cell transplant from a donor with two CCR5 Δ32 alleles, but to treat leukaemia.
Both patients experienced mild graft-versus-host disease, which may also have played a role in the loss of HIV-infected cells.
Professor Gupta said: “By achieving remission in a second patient using a similar approach, we have shown that the Berlin Patient was not an anomaly and that it really was the treatment approaches that eliminated HIV in these two people.”
The researchers caution that the approach is not appropriate as a standard HIV treatment due to the toxicity of chemotherapy, but it offers hope for new treatment strategies that might eliminate HIV altogether.