Also available in: Español
Source: https://www.agenciasinc.es/Noticias/Confirmada-la-cura-de-un-segundo-paciente-con-VIH
A team of researchers, with the participation of IrsiCaixa, have pronounced the HIV cure in the so-called ‘London patient’ after verifying that the virus does not continue in his body after 29 months without treatment. At the same time, they have announced a third case of remission, the ‘Düsseldorf patient’.
The London patient, a man with HIV, was diagnosed with Hodgkin lymphoma (a cancer of the immune system). In 2016, he underwent a stem cell transplant with a mutation, called CCR5 Delta 32, that blocks the virus from entering HIV cells, to the CD4 T lymphocytes.
After 16 months, the doctors interrupt the antiretroviral treatment and in March 2019, the Nature journal published an article showing that he had been HIV undetectable in his blood for 18 months, becoming the second case long-term remission. This was the second case in the world, after the Berlin patient in 2009.
Today, an article published in The Lancet HIV magazine highlights that now, 29 months after treatment interruption, the virus is still undetectable in blood, brain-spinal fluid, intestinal tissue and semen. Therewith, the study that includes the participation of IrsiCaixa confirms the HIV “cure” of the so-called London patient.
The virus is still undetectable in blood, brain-spinal fluid, intestinal tissue, and semen.
Viral DNA fossils
The patient analyses detect very low levels of HIV genome in lymphoid tissues, but this is defective genetic material that has no replicative capacity and, therefore, no infectious capacity. “All this pushes us to conclude that this is a second case of cure because in the Berlin patient fossil viral DNA was also detected without infectious capacity,” explained Martínez-Picado.
The London patient has antibodies against HIV, although they are at a very low level and have experienced a continuous decline since the transplant. This may happen because the new cells of the immune system have been exposed to the virus, but according to the IrsiCaixa researcher María Salgado, who is part of this project –called IciStem–, “it is common that evidences of past infection persist in the organism, since antibodies can take years to disappear. ”
Third case of remission
The publication comes to light matching with the Conference of Retrovirus and Opportunistic Infections (CROI), the most important world conference on AIDS, which had to be held in Boston (USA) but at the end, because of the coronavirus, it would take place virtually.
During the same conference, the IciStem consortium presents a third case of HIV long-term remission after a bone marrow transplant: the Düsseldorf Patient, who has been virus-free for 14 months in the absence of antiretroviral medication.
The researchers set the concepts apart of “cure” and “long-term remission” based on the length of time without viral rebound since the antiretroviral medication interruption.
“When the London case was initially published, we insisted on not talking about a cure because, although 18 months invited a lot of optimism because we had not seen such a long interval since the” Berlin patient “, we wanted to be prudent and not generate false expectations”, stated Javier Martínez-Picado, ICREA researcher at IrsiCaixa and co-coordinator of IciStem.
They set the concepts apart of “cure” and “long-term remission” based on the length of time without viral rebound
The Düsseldorf Patient is a 50-year-old man with HIV infection who received a stem cell transplant in February 2013 to treat acute myeloid leukemia. Donor cells also had the CCR5 Delta32 mutation. In November 2018, doctors interrupted antiretroviral medication and, 14 months later, there is still no viral rebound.
Virus traces
The analysis shows viral DNA traces, although they have not infectious capacity. According to the researchers, the results “are compatible with a sustained remission of HIV.”
Usually, when people with HIV infection interrupt treatment, the virus rebounds over the first 4 weeks. The lack of rebound in these cases is due to the fact that donor cells are resistant to HIV, and in as much as they replace the recipient cells after transplant, chances of infection for the virus decrease and it ends up disappearing.
Despite this success, Martínez-Picado highlighted that “there remain a number of barriers to overcome before CCR5 gene editing can be used as a scalable cure strategy for HIV” for the entire population.
IciStem, a research project looking for an HIV cure, has included, since 2014, 40 HIV patients who underwent a stem cell transplant. Researchers highlight that stem cell transplant is a high-risk medical procedure and it is only recommended to patients suffering from a disease that cannot be treated by other therapies. They also emphasize that antiretroviral therapy interruption can only be done by medical decision.
Source: IrsiCaixa
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