Dix years after the confirmation of the first case of remission in an HIV-positive patient who had gotten rid of the disease, this second case, nicknamed “the London patient”, has shown no sign of the virus for nearly 19 months, when he stopped his treatment, report Tuesday in the journal Nature a team of researchers, who consider him to be probably cured.
Both patients underwent bone marrow transplants to treat blood cancers, and thus received donor stem cells with a rare genetic mutation that prevents HIV from implanting.
“This is a landmark result. After 10 years of inability to reproduce [le premier cas], people wondered if it was a fluke, ”said lead author Ravindra Gupta, professor at the University of Cambridge. “It is important to reaffirm that this is real and that it can be done,” he told AFP.
Cautiously, he does not use the heavy word “cure”, warning that such a declaration would require a longer remission.
“In six months or two years, things will be clearer,” Ravindra Gupta said at a press conference in Seattle, United States, at the Annual Conference on Retroviruses and Opportunistic Infections (CROI), where the team presented the result. “The press release was cautious,” he added. “If people interpret it in the wrong way, it’s not good journalism.”
Millions of people infected with HIV around the world control the disease with antiretroviral therapy (ARVs), but this therapy does not get rid of the virus and must be taken for life.
Bone marrow transplantation – a dangerous and painful procedure – is not a viable option for the recovery of the majority of patients, take care to stress Pr Gupta and his team.
But this second case of remission and likely recovery will help scientists narrow the range of treatment strategies.
Some 37 million people are living with HIV worldwide, but only 59% are receiving triple therapy. Almost one million people still die from HIV-related illnesses each year. The emergence of drug-resistant forms of HIV is also of growing concern.
“A lot of hope”
The International AIDS Society hailed “a milestone in the search for a cure for HIV.” “This gives us a lot of hope that in the future we could perhaps put an end to AIDS thanks to science, a vaccine or a remedy”, commented Michel Sidibé, president of the United Nations agency UNAIDS. .
The “patient from London” as well as the “patient from Berlin” (nickname of the first case) received injections of stem cells from donors carrying a genetic mutation which renders inoperative an HIV receptor, CCR5.
This anonymous British patient was diagnosed with HIV in 2003 and had been on antiretroviral therapy since 2012.
Also diagnosed in 2012 with an advanced form of Hodgkin’s disease, a cancer of the lymphatic system, in 2016 he underwent a hematopoietic stem cell transplant from a donor carrying a mutation in the very rare CCR5 gene. present in 1% of Europeans.
HIV-1 mostly uses CCR5 as a receptor. But this mutation in the CCR5 gene prevents the virus from entering host cells, making carriers of this mutation resistant to the AIDS virus.
“CCR5 is an essential building block for the virus to complete its life cycle,” said Pr Gupta, according to whom this gene “can be eliminated without serious consequences” for the patient.
Undetectable viral load
It is the replacement of immune cells by those which do not have the CCR5 receptor that seems to be the determining factor in preventing the reappearance of HIV after treatment.
After the bone marrow transplant, the “patient from London” continued his antiretroviral treatment for 16 months, before stopping it.
Regular tests have confirmed that his viral load has been undetectable since.
Timothy Brown, the “patient from Berlin”, had undergone two transplants as well as irradiation on the whole body.
In contrast, the “London patient” had only one transplant and less aggressive chemotherapy.