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A man known as the "Geneva patient" began a long recovery from HIV after a bone marrow transplant in which, unlike what was recorded in previous similar treatments, a mutation that prevents the virus from entering cells did not appear, thus opening up the possibility of conducting research in this area.
The case of this patient was presented Thursday in Brisbane, prior to the opening of the International AIDS Society conference Sunday in Australia.
Five people before him were considered HIV-positive after undergoing a bone marrow transplant.All the patients who recovered had a very special common condition, that they had leukemia and were given a stem cell transplant that radically rejuvenated their immune system. But each time, the donor had a rare mutation in a gene known as CCR5 delta 32, a genetic mutation known to prevent HIV from entering cells.
As for the "Geneva patient", the situation is different. In 2018, he underwent a stem cell transplant to treat a very harmful form of leukemia, and this time, the transplant came from a donor who did not carry the CCR5 mutation. Thus, unlike the cells of others classified as recovered, the donor cells of the "Geneva patient" do not theoretically prevent HIV from multiplying.
However, no virus was detected 20 months after cessation of ART in this patient who was being monitored by Geneva University Hospitals in collaboration with the Institut Pasteur, the Institut Cochine and the international alliance IciStem.
His antiretroviral treatment was gradually tapered off, and was finally discontinued in November 2021.
Analyzes conducted during the 20 months following the cessation of treatment did not detect any viral particles, no reactivable viral stock, and no increase in immune responses against the virus in this patient's body.
The scientific teams did not rule out that the virus is still present, but they considered that this patient's condition constitutes a new recovery from HIV.
Marrow transplants without the protective mutant had previously been performed for other HIV-infected patients before the Geneva Patient.
"The virus reappeared after a few months," said the head of the viral stocks and immune control unit at the Institut Pasteur Asier Saez Sirion, told AFP.
"We consider that the passage of more than 12 months without detection of the virus significantly increases the likelihood that it will continue to remain undetected in the future," he added.
There are several hypotheses put forward to explain this phenomenon in the "Geneva patient".
“In this particular case, the transplant may have killed all the affected cells without the need for the protective mutants,” Saez-Sirion said, or “maybe his immunosuppressive therapy, which is necessary after transplantation, played a role.”
While acknowledging that this long recovery is "encouraging," Sharon Lewin, President of the International AIDS Society Conference, cautioned that "a single virion (an infectious viral particle) can lead to virus recovery." He added that this patient "will need to be monitored closely over the next few months or even years. It is impossible to predict the likelihood of a recovery."
Although these cures provide hope that one day HIV will be overcome, bone marrow transplantation remains heavy and risky, and is not adaptable to most HIV carriers.
In any case, the researchers considered that this "exceptional" case opens new horizons for research, such as the role that immunosuppressive therapies can play.
Source Lebanon Files - Published on Friday, July 21, 2023
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