First patient with HIV cured with cells donated by a brother

BarcelonaMedicine showed its most spectacular face seventeen years ago with the functional cure of the first patient with human immunodeficiency virus (HIV). But now the case of Timothy Ray Brown, known globally as the Berlin patient, has ceased to be an exception: there are now ten people worldwide who have managed to eliminate the virus through a complex but effective stem cell transplant. The most recent case is that of the so-called Oslo patient, a 62-year-old Norwegian and seropositive man, who was also diagnosed with an immune system cancer and required this intervention. Four years later, and despite having stopped receiving antiretroviral drugs, the virus remains undetectable. With a peculiarity compared to previous cases: his donor is his own brother.

This tenth case is published this Monday in the journal Nature Microbiology as part of a study led by the Oslo University Hospital, which also involved IrsiCaixa, a center jointly promoted by the La Caixa Foundation and the Department of Health. "HIV can be cured. There are already ten patients in remission, it's not a coincidence, and more will come. We are also developing new strategies that can benefit more people," Javier Martínez-Picado, an Icrea researcher at IrsiCaixa, explains to l'ARA. The researcher clarifies that the less complex treatments they are developing are still in an early phase, and that we will have to wait for them to become a reality and reach the rest of the patients.

All the cure cases described so far are of people with HIV and some hematological cancer who needed a stem cell transplant to combat this second disease. In these cases, donors with a specific genetic mutation, called CCR5Δ32, which prevents the virus from entering cells, are sought. The pathogen is capable of forming reservoirs and does not disappear entirely, which is why people with HIV are chronic patients and must receive lifelong preventive treatment. If they stop this therapy, the virus reappears after a few days. In contrast, as the ten successful cases have shown so far, if stem cells are taken from people with this mutation and transplanted to a person with HIV, it is possible to prevent the virus from infecting the new cells, explains the researcher.

In the case of the Oslo patient they did not find a compatible donor and finally opted for his brother, who, to the surprise of the authors, was a carrier of the mutation. Martínez-Picado, who is also coordinator of IciStem 2.0, the international consortium dedicated to the study of HIV cure with stem cell transplants, explains that in Norway the mutation is more frequent than in other countries: 2.5% of the population has it. This would explain why the brother did have it and the patient did not. Nevertheless, it has become the first case of cure with a transplant from a brother and also one of the oldest, as the patient is over sixty years old. Four years after stopping medication, the patient continues to have no detectable trace of the virus.

New strategies

One of the strategies that IrsiCaixa is studying so that more people can opt for an HIV cure is through cell therapy, which has already proven successful against some cancers and immune diseases. The therapy is called CAR-T, and the patient is their own donor. Specifically, T lymphocytes (which are natural defenses) are extracted from the sick person, genetically reprogrammed in the laboratory to recognize and destroy the target cells of HIV, and reinoculated into the bloodstream. "We are in a very early phase," insists researcher Martínez-Picado. Other research lines at the center are focused on investigating gene therapies to modify the CCR5 gene and induce the famous CCR5Δ32 mutation, thus blocking the virus's entry into cells, although these approaches are also in preliminary stages.