The IciStem consortium, coordinated by IrsiCaixa, presents the third case of recovery from an HIV infection in the world. This is a man who was taken off supervised antiretroviral therapy for HIV after undergoing a stem cell transplant to treat myeloid leukaemia. Four years later, the virus has not reappeared. The study is published in the journal Nature Medicine, in an article demonstrating the absence of viral particles and immune response against the virus in the patient’s body despite the absence of treatment for 4 years, proof that allows the scientific team to consider the case of the patient from Düsseldorf as a new case of recovery.
The study was carried out by the international consortium IciStem, coordinated by the Institute for AIDS Research IrsiCaixa – a center jointly promoted by the “la Caixa” Foundation and the Ministry of Health of the Catalan government – and the University Medical Center from Utrecht (Netherlands). “With an excellent team of professionals from all over the world, we have been studying for nine years these exceptional cases in which, thanks to a therapeutic strategy, the virus is completely eliminated from the organism. We want to understand in detail each step of the healing process in order to to design strategies that can be replicated in the entire population”, explains Javier Martínez-Picado, ICREA researcher at IrsiCaixa, co-director of IciStem and co-author of the article.
The patient from Düsseldorf, a story of overcoming the disease
In 2008, a medical team from Düsseldorf (Germany) diagnosed an HIV infection in a person who would later be known as the “Düsseldorf patient” due to his uniqueness. After diagnosis, the patient was put on antiretroviral therapy, which brought his infection under control and reduced the amount of virus to undetectable levels in his blood. Four years later, in 2012, he developed leukemia, a cancer of the cells of the immune system, and had to undergo a stem cell transplant. In these unique cases, we are looking for a stem cell donor who has the CCR5Δ32 mutation. This genetic alteration means that one of the entry gates of HIV into the cells is not produced and therefore makes infection more difficult. “It is very complicated that all these factors coincide, only 1% of the population has this mutation and, moreover, it is necessary that the donor be a compatible blood donor to avoid rejection of the transplant”, explains Maria Salgado, IGTP researcher at IrsiCaixa and co-author of the study. In the case of the Düsseldorf patient, a woman helped put all the pieces of the puzzle together.
More than 5 years after the transplant, and after going through two relapses of leukemia and several complications, the patient has stabilized. From there, the research team agreed to remove him from antiretroviral treatment for HIV. Today, the patient from Düsseldorf is 53 years old and in good health. “When he stopped his treatment, we followed him for 44 months and did not detect any trace of virus in his blood or in his tissues”, specifies Salgado. “We also did not observe an immune response characteristic of a viral surge. His defenses are not activated against HIV because he does not have to defend against the virus”. All these data allow the scientific team to affirm that the person has been cured of HIV infection.
The HIV Cure World Map
The confirmation of the recovery of the patients from Berlin and London precedes that of the patient from Düsseldorf. Although these are the only three cases in which we can speak of a cure, the HIV remission of two other patients, that of New York and that of the City of Hope hospital in Duarte, has already been presented during scientific conferences. “Neither have special immune characteristics that allow them to spontaneously control HIV infection, but the virus has been cleared from the body as a result of medical intervention. This differentiates those cases of eradication of cases of functional cure in elites or post-treatment controllers made so far, where people’s organism had special factors that allowed them to control the virus,” Salgado explains. The Düsseldorf patient is therefore a third proof of concept that demonstrates the possibility of curing HIV and rekindles hope in the scientific world dedicated to the fight against the virus.
However, this strategy is very aggressive and cannot be transposed to the rest of the population. Stem cell transplantation is only applied to people suffering from a hematological disease and having no therapeutic alternative. In the case of HIV-positive people, there is an alternative, namely antiretroviral treatment. “A possible strategy, which is already being worked on, is to introduce the CCR5Δ32 mutation through gene therapy in order to achieve a cure for HIV without having to undergo a transplant”explains Martínez-Picado.