His case was presented Thursday in Brisbane, ahead of the International AIDS Society Conference which opens Sunday in Australia.
Before him, five people have already been considered probably cured of HIV infection following receiving a bone marrow transplant.
The cured patients all had a very particular situation in common. They were suffering from blood cancers and benefited from a stem cell transplant which deeply renewed their immune system.
But each time, their donor presented a rare mutation of a gene known as CCR5 delta 32, a genetic mutation known to prevent the entry of HIV into cells.
For the “patient from Geneva”, 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 HIV to reproduce.
And yet, the virus remains undetectable 20 months following 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 stopped in November of 2021.
And the analyzes carried out during the 20 months which followed the cessation of treatment did not detect any viral particles, any activatable viral reservoir, or an increase in immune responses once morest the virus in the body of this person.
The scientific teams cannot exclude that the virus still persists, but they consider that this is a new remission of the HIV infection.
“Closely Watched”
Other patients with HIV had benefited before him from marrow transplants without the famous protective mutation.
More “the virus reappeared following a few months”told AFP Asier Sáez-Cirión, head of the Viral Reservoirs and Immune Control Unit at the Institut Pasteur.
“We consider that when we exceed 12 months of undetectable virus, the probability that it will remain undetectable in the future increases significantly”he adds.
How to explain such a phenomenon in this patient? Several hypotheses are on the table.
“In this specific case, perhaps the transplant has eliminated all the infected cells without the need for the famous mutation”forward M. Sáez-Cirion. “Or maybe his immunosuppressive treatment, necessary following the transplant, played a role”.
This long remission is “encouraging” more “a single virion (an infectious viral particle, editor’s note) can cause the virus to rebound”warned Sharon Lewin, president of the International AIDS Society Conference.
This patient “will have to be watched closely over the next few months or even years. The likelihood of a rebound is impossible to predict”he added.
If these remissions nourish the hope of one day overcoming HIV, a bone marrow transplant remains a very heavy and risky operation: it is not adaptable to most carriers of the virus.
These cases nevertheless open up new avenues of research, such as the possible role that immunosuppressive treatments might play.
“It also encourages us to continue to study certain cells of innate immunity” (the first barrier of defense once morest various pathogens, editor’s note), likely to influence the control of the virus, adds Asier Sáez-Cirión.
The patient from Geneva, who had been living with HIV since the early 1990s, wishes to remain anonymous for the time being. “What is happening to me is magnificent, magical“, he simply reacted in a press release from the Institut Pasteur.
