A man referred to as “the Geneva patient” is in long-term HIV remission after receiving a bone marrow transplant that lacked a mutation known to block the virus, news that potentially opens avenues for research.
His case was presented this Thursday in Brisbane, ahead of the Conference of the International AIDS Society that will open on Sunday in Australia. Before him, five people have already considered themselves probably cured of HIV infection after receiving a bone marrow transplant.
All the cured patients had a very particular situation in common. They suffered from blood cancers and benefited from a stem cell transplant that profoundly renewed their immune systems. But each time, her donor carried a rare mutation of a gene known as CCR5 delta 32, a gene mutation known to prevent HIV from entering cells.
a very special situation
For the “Geneva patient”, the situation is different: in 2018, to treat a particularly aggressive form of leukemia, he benefited from a stem cell transplant.
But this time, the transplant came from a donor who did not carry the famous CCR5 mutation. Thus, unlike the cells of other people considered cured, those of the donor person theoretically allowed the reproduction of HIV.
And yet, the virus remains undetectable 20 months after the interruption of antiretroviral treatment in this patient followed at the University Hospitals of Geneva, in collaboration with the Institut Pasteur, the Institut Cochin and the international consortium IciStem.
His antiretroviral treatment was gradually reduced and definitively suspended in November 2021. And the analyzes carried out during the 20 months that followed the cessation of treatment did not detect viral particles, or an activatable viral reservoir, or an increase in the immune responses against the virus in the body. of that person.
The scientific teams cannot rule out that the virus still persists, but they consider that it is a new remission of the HIV infection.
The patient will have to be monitored for many months.
How to explain such a phenomenon in this patient? There are several hypotheses on the table. “In this specific case, perhaps the transplant made it possible to eliminate all the infected cells without the need for the famous mutation,” suggests Asier Sáez-Cirión, head of the Viral Reservoirs and Immunological Control Unit at the Pasteur Institute.
“Or maybe his immunosuppressive treatment, which was necessary after the transplant, played a role,” she says.
This long remission is “encouraging” but “a single virion (an infectious viral particle, editor’s note) can cause the virus to rebound,” said Sharon Lewin, president of the International AIDS Society Conference. This patient “will need to be watched closely for months or even years to come. The likelihood of a rebound is impossible to predict,” she added.
If these remissions feed the hope of one day defeating HIV, a bone marrow transplant remains a very heavy and risky operation: it is not adaptable to the majority of virus carriers.
The Geneva patient, who has been living with HIV since the early 1990s, wishes to remain anonymous for now. “What is happening to me is magnificent, magical”, he limited himself to reacting in a press release from the Institut Pasteur.
Source: BFM TV
