2023-07-24 22:00:00
“An exceptional case”: a man designated as “the patient of Geneva” is in long remission from HIV after receiving a bone marrow transplant that does not have a mutation known to block the virus.
Before him, five people have already been considered probably cured of HIV infection after receiving a bone marrow transplant. The cured patients were suffering from blood cancer and benefited from a stem cell transplant which deeply renewed their immune system. The particularity is that each time, their donor presented a rare mutation of a gene called 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, 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 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 stopped in November 2021.
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 against the virus in the organism of this person.
The scientific teams cannot exclude that the virus still persists, but consider that it is a new remission of the HIV infection.
Other patients with HIV had benefited before him from marrow transplants without the protective mutation. But “the virus reappeared after a few months,” says 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.
Several hypotheses can explain such a phenomenon in this patient. “In this specific case, perhaps the transplant made it possible to eliminate all the infected cells without the need for the famous mutation,” says Sáez-
Cirion. Or perhaps his immunosuppressive treatment, required after the transplant, played a role. »
An “encouraging” remission, but…
This long remission is “encouraging”, but “a single virion (an infectious viral particle) can cause the virus to rebound”, warned Sharon Lewin, president of the International AIDS Society Conference. This patient “will need to be monitored closely over the next few months, if not 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.
This “exceptional” case, according to the researchers, in any case opens up new avenues of research, such as the role that immunosuppressive treatments could play. “It also encourages us to continue to study certain cells of innate immunity” (the first defense barrier against various pathogens), which may influence the control of the virus, adds Asier Sáez-Cirión.
“We know that we are not going to transplant all patients who have HIV, but this opens doors to try to obtain lasting remissions in the absence of a transplant with mutation”, underlined Pr Alexandra Calmy, head of the HIV Unit at the University Hospitals of Geneva.
The patient, who had been living with HIV since the early 1990s, wishes to remain anonymous for the time being. He considers this remission “as a miracle that he dedicates to the future and to research”, underlined Professor Calmy.
Dan LAWLER et
Isabelle TOURNÉ/AFP
“An exceptional case”: a man referred to as “the Geneva patient” is in long remission from HIV after receiving a bone marrow transplant that does not have a known mutation to block the virus. Before him, five people have already been considered probably cured of HIV infection after receiving a…
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