The global pursuit of an HIV cure has reached a significant milestone with a seventh documented case of sustained remission, offering fresh optimism for the roughly 39 million people living with the virus worldwide.The patient, who underwent a stem cell transplant for leukemia, has shown no detectable trace of HIV years after ceasing antiretroviral therapy. This latest success is particularly noteworthy as it demonstrates that HIV remission may be possible even without the rare CCR5 genetic mutation previously considered crucial for such outcomes, potentially broadening the scope of curative treatment options [[1]].
The number of people living with HIV who have achieved remission has grown to seven, offering renewed hope in the ongoing search for a cure. The latest case involves a man who stopped testing positive for HIV after receiving a stem cell transplant to treat leukemia, a blood cancer. This case is particularly significant as it’s the second of the seven individuals to achieve remission after receiving stem cells that weren’t specifically resistant to HIV, suggesting that resistance may not be essential for a successful outcome.
The Breakthroughs in HIV Remission and a Rare Genetic Mutation
The journey toward HIV remission began in 2009 with Timothy Ray Brown, often referred to as the “Berlin patient,” who was the first person documented to be cured of HIV. Since then, five other individuals – the “London patient” and the “Düsseldorf patient” among them – have experienced HIV remission following stem cell transplants from donors carrying a rare genetic mutation that provides resistance to HIV infection. This mutation, found in only about 1% of the population, disables the CCR5 protein, which the virus typically uses to enter blood cells. However, as reported previously, a sixth patient, known as the “Geneva patient,” was declared virus-free for over two years after receiving stem cells lacking this CCR5 mutation. “It was thought that using these HIV-resistant stem cells was essential,” explained researcher Christian Gaebler. “Seeing that remission is possible without this resistance gives us more options for treating HIV.”
The implications of these findings are substantial, as they broaden the potential pathways toward a functional cure for HIV, a virus that continues to affect millions globally.
Details of the Seventh Case
The seventh patient, whose case further supports this evolving understanding, was diagnosed with HIV and then received stem cells in October 2015 to treat acute myeloid leukemia. The treatment included chemotherapy to eliminate most of his immune cells, creating space for the donor’s stem cells to take hold. Because a donor with two copies of the CCR5 mutation wasn’t available, doctors used a donor with one normal copy and one mutated copy of the CCR5 gene. Three years after the transplant, the patient stopped taking antiretroviral therapy (ART), and shortly after, researchers found no trace of the virus in his blood samples. He has remained virus-free long enough to be considered “cured.”
A study published in Nature details the findings of this case, led by a team of researchers at Charité – Universitätsmedizin Berlin in Germany.
Looking Ahead: Expanding the Possibilities for HIV Remission
The new research confirms that having two copies of the CCR5 mutation isn’t a prerequisite for achieving HIV remission, shifting the focus away from the difficult search for rare donors. This suggests that a wider range of stem cell transplants – including those from donors without two copies of the mutation – “could potentially cure HIV,” Gaebler told New Scientist. He noted that many factors likely contribute to remission, including the patient’s genetics; in this case, the man carried one copy of the CCR5 mutation, which “may have facilitated viral remission.” This means that more people undergoing stem cell transplants for both HIV and blood cancers should be considered for HIV-resistant stem cells when available.
It’s important to note that stem cell transplants are a high-risk procedure, potentially causing life-threatening infections, and are not suitable for people with HIV who do not also have cancer, Gaebler cautioned.
Originally published in WIRED Italia.
