A man from Düsseldorf, now 53 years old and who suffered from leukemia, has been in remission for four years with the virus
The Science has confirmed the third case of HIV cure in the world after a stem cell transplant. After the Berlin patient (2008) and the London patient (2019), now comes the Düsseldorf patient. Although the process by which they have been cured of HIV is complex and cannot be applied to all people with the infectionthis new medical milestone demonstrates that researchers are getting closer to curing HIV.
‘Nature Medicine’ has just published a study by the IciStem consortium, coordinated by the IrsiCaixa AIDS Research Institute (in turn, promoted by the La Caixa Foundation, as well as by the Department of Health of Catalonia) and by the University Medical Center of Utrecht (Netherlands). This is the case of a man whose antiretroviral treatment against HIV was withdrawn under supervision after undergoing a stem cell transplant to treat myeloid leukemia. Four years later, the virus has not reappeared.
The investigation demonstrates the absence of viral particles and an immune response against the virus in the patient’s body despite not receiving treatment for four years, evidence that allows the scientific team to consider that the case of the Düsseldorf patient is a new case of cure. .
“We carry nine years studying these exceptional cases in which, thanks to a therapeutic strategy, the virus is completely eliminated from the body. We want to understand each step of the curing process in detail to be able to design strategies that are replicable for the entire population”, explains Javier Martínez-Picado, ICREA researcher at IrsiCaixa, co-director of IciStem, and co-author of the article.
The Düsseldorf patient
In 2008, a medical team in Düsseldorf, Germany, diagnosed HIV infection in a person who would later be known as the Düsseldorf patient. After diagnosis, the patient started antiretroviral treatment, which allowed to control the infection and reduce the amount of virus to undetectable levels in the blood. Four years later, in 2012, she suffered leukemia, that is, a cancer in the cells of the immune system. Thus, they had to perform a stem cell transplant.
In these unique cases, a stem cell donor is sought who has a mutation called CCR5 Delta 32 (CCR5d32). This genetic alteration prevents virus entry into HIV target cells (or, what is the same, in the cells through which the virus spreads in the body): the T-CD4 lymphocytes. In this way, infection is difficult. “That all these factors coincide is very complicated, only 1% of the population has this mutation and, in addition, it is necessary for it to be a blood-compatible donor to avoid transplant rejection”, remarks Maria Salgado, a researcher at IrsiCaixa and study co-author.
More than five years after the transplant, and having experienced two relapses of the leukemia and several complications, the patient stabilized. From there, the research team agreed to withdraw the antiretroviral treatment against HIV. As of today, the patient from Düsseldorf is 53 years old and in good health. “When he stopped taking the treatment, we did a follow-up for 44 months and we did not detect any trace of the virus in the patient’s blood or tissues,” says Salgado. “We have not seen any characteristic immune response of a viral outbreak either. Their defenses are not activated against HIV because they do not have to defend themselves against the virus”, he adds. The scientific team affirms that the person has been cured of the HIV infection.
stem cell transplant
The for now three patients in the history cured of HIV shared a characteristic: they had a hematological cancer. The first, the Berlin patient, was Timothy Brown (he ended up revealing his identity), who died in 2020, but not from HIV, but from the terminal cancer he suffered from: leukemia (like the Düsseldorf patient). The second, the London patient (who served, 11 years later, to confirm the case of Timothy Brown), had Hodgkin’s lymphoma. All three patients received a stem cell transplant that cured them of HIV. In addition, the cells that they transplanted to all three had that CCR5 Delta 32 (CCR5d32) mutation. However, the doctors clarify, stem cell transplantation is a high-risk intervention and is only recommended for patients with severe hematological problems. The risk of death is between 40% and 50% chance. That is why it is not the solution to cure HIV.
Researchers are designing therapies to be able to do this long-term. Gene therapy (which involves removing cells, treating them in the laboratory, and reimplanting them in the patient) is a possible future cure for this disease, but it is still in development. preclinical phase. The researchers emphasize that the patient, in no case, should interrupt antiretroviral treatment on their own, but should always do so on medical advice.