A patient from Düsseldorf (Germany) has become the world’s third confirmed case of being cured of HIV after receiving a stem cell transplant to treat leukemia, bringing the possibility of a large-scale treatment one step closer.
The case has been studied by the IciStem consortium, coordinated jointly by the University Medical Center of Utrecht (The Netherlands) and the IrsiCaixa AIDS Research Institute of Badalona (Barcelona, Spain), a center promoted jointly by the La Caixa Foundation and the Department of Health of the Generalitat.
It is about a man, who prefers to remain anonymous, who was withdrawn from antiretroviral treatment against HIV in a supervised manner after undergoing a stem cell transplant to treat myeloid leukemia and, four years later, the virus has not reappeared.
Immune response against the virus
The study, published today in the journal Nature Medicine, has shown the absence of HIV and an immune response against this virus in the patient’s body despite not receiving treatment for four years, evidence that allowsto certify that it is a new case of healing.
In 2008, a medical team in Düsseldorf, Germany, diagnosed this patient with HIV infection and started standard antiretroviral treatment, which controls the infection and reduces the amount of virus to such minimal levels that it is undetectable in a blood test, and they do not have contagion capacity either.Four years later, in 2012, he suffered from leukemia, for which he underwent a stem cell transplant.
In these very unique cases, a stem cell donor is sought who has a mutation called CCR5 Delta32, which prevents the body from producing one of the entry doors for HIV into cells and, therefore, makes infection more difficult.
More than five years after the transplant, and having gone through two relapses of leukemia and various complications, the patient stabilized and the research team agreed to withdraw antiretroviral treatment against HIV.
“Ten years have passed since the transplant and four since the antiretroviral was discontinued; Normally, when the treatment is stopped, the virus reappears in four days, so four years is a sufficient period to announce that it is a case of cure,” the co-author of the article and IrsiCaixa researcher, Javier Martínez-Picado, explained.
A cure with medical intervention
There are two previous cases considered to be cured, a patient in Berlin (confirmed in 2011) and one in London (2020), who, like the one in Düsseldorf, underwent a stem cell transplant, a medical intervention that is only applied to people suffering from a hematological disease.
“These are patients who have suffered leukemia or lymphoma and, in addition, were carriers of HIV, but this transplant is a very high-risk medical intervention only reserved for people who have no other option from the hematological point of view,” Martínez-Picado pointed out.
In addition, it is difficult “to find a suitable donor, who is not only compatible for the transplant, but also has this mutation (CCR5 Delta32), and in that the probability is very low, about 1 in 1 million approximately”.Thus, this route is not applicable on a large scale, but it does show the way to a possible solution for all those infected.
In this sense, researchers have been working for some time on this CCR5 Delta32 protein, capable of preventing infection, with the aim of genetically modifying it and implanting in cells that, once reintroduced into the patient, can rapidly expand to cure the disease.
Already a reality
“The cure of HIV in a timely manner is already a reality and, at a scalable level for the rest of the population, it is getting closer,” predicted Martínez-Picado, who recalled that work is also being done on preventive vaccines that would complete this future curative strategy.
Achieving a large-scale cure of HIV would allow patients to stop taking antiretroviral treatment for the rest of their lives — lucrative for pharmaceutical companies but costly for the public system — and would end the stigma they still suffer.
