Toronto man’s HIV no longer detectable after bone marrow transplant A Toronto man who has lived with HIV for 27 years is in sustained remission and potentially cured following a bone marrow transplant from a donor with natural resistance to the virus, according to medical teams at the University Health Network (UHN), Unity Health Toronto, and the University of Toronto. The patient, diagnosed with HIV in 1999 and later with an aggressive form of leukemia in November 2021, underwent the transplant as part of his cancer treatment. His medical team recognized an opportunity to simultaneously target his HIV by selecting a donor stem cell match carrying the CCR5-delta 32 genetic mutation, which confers resistance to HIV infection. Dr. Sharon Walmsley, HIV Clinic Director at UHN’s Toronto General Hospital and Speck Family Chair in Emerging Infectious Diseases, has been the patient’s physician since his HIV diagnosis. She noted that achieving sustained remission with undetectable HIV levels for nearly a year would have been considered inconceivable just a few decades ago. “We feel pretty confident that it’s gone, but it’s hard for us to say for absolute sure right now that he is cured,” Dr. Walmsley said. “If he remains in remission for about two and a half years, the 36-year-old will join 10 people in the world currently considered cured of HIV.” The case marks a Canadian first in HIV remission achieved through a bone marrow transplant using HIV-resistant donor stem cells. While such transplants are not a standard treatment for HIV due to their complexity, cost, and risks, they are considered for patients who also require transplantation to treat life-threatening conditions like leukemia or lymphoma. The approach builds on the precedent set by the “Berlin patient” in 2007, the first person believed to be cured of HIV through a similar procedure. Since then, only a small number of cases worldwide have achieved sustained remission or potential cure using this method. Medical experts emphasize that bone marrow transplants remain high-risk procedures and are not viable as a broad HIV cure strategy. However, each successful case provides valuable insight into potential pathways toward an HIV cure and informs ongoing research into gene therapy and immune-based approaches. The patient continues to be monitored closely by his medical team. Long-term follow-up will be essential to confirm whether HIV remains undetectable without antiretroviral therapy, which would meet the criteria for a functional cure.
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