Another Patient has Been Cured of HIV, But This One is Different | AIDS 2024

Another patient appears to have been cured of HIV following a stem cell transplant, making this the seventh person who has achieved remission from HIV and has been able to stop taking antiretroviral medications, according to a case presented today by Christian Gaebler, M.D., professor for Translational Immunology of Viral Infections at Charité – Universitätsmedizin Berlin. The presentation was made at a press conference ahead of the International AIDS Conference that is beginning next week in Munich, Germany.

Even more important is that this is the first case of remission in which the stem cell donor had a single, rather than double, CCR5-delta32 mutation. In previous cases of remission following stem cell transplants, the stem cell donors had two copies of the CCR5-delta32 mutation, which hampers HIV’s ability to infect cells.

Christian Gaebler, M.D.

“We believe that this remarkable case and the results of our studies really suggest that it is possible to cure HIV, even when the functional receptor for the virus is present. And it shows us that polygenic immunity plays a fundamental role in HIV eradication beyond this rare Delta 32 CCR five mutation,” Gaebler said at the press conference.

The patient in this case, who has chosen to remain anonymous, was diagnosed with HIV in 2009, and then required chemotherapy and stem cell transplantation to treat acute myeloid leukemia in 2015. Gaebler and his team were unable to find a donor with two copies of the CCR5-delta32 mutation, but a donor with one copy was found.

“The allogenic stem cell transplantation went well,” Gaebler said. “It was well-tolerated and successfully treated the blood cancer. However, to our great surprise, it also became clear that the stem cell transplantation had effectively depleted the HIV reservoir after the patient discontinued his recommended antiviral treatment on his own in 2018.”

Gaebler said that since then, the patient has been in remission and has shown no detectable HIV in his blood. “We've performed comprehensive HIV reservoir testing, including in blood, but also various tissues from tissue reservoirs, and we have found no signs of HIV,” he said. “In addition, HIV specific antibody levels decreased since the transplantation and HIV specific T cell responses were undetectable.”

He suggested in a question-and-answer period that the immunity from allogeneic stem cell transplantation donor is what leads to the depletion of the HIV reservoirs and the addition of the CCR5-delta32 mutation adds protection with a resistant immune system.

Researchers suggests the stem cell donor pool could be expanded to those with one copy of the CCR5-delta32 mutation. This also opens the doors to more cures for HIV, possibly based on gene therapy. Gaebler said a possible gene therapy could target the CCR5 receptor. “These human cases really show us that maybe it would be possible to achieve a level of reservoir depletion reduction that could lead to long-term HIV cure cases.”