A 53-year-old man is free from HIV thanks to a stem cell transplant received to cure himself of leukemia: the cases can be counted on the fingers of one hand.
A 53-year-old from Düsseldorf, Germany, has been declared “officially free” of HIV nine years after a stem cell transplant he received to recover from a form of leukaemia. The one just described on Nature Medicine it is one of five cases in the world of complete cures of the virus that causes AIDS – although, given the dangerous nature of the treatment, it would be inappropriate to say that we have found a cure for HIV. In fact, these are very rare events, which are included in the scientific literature and which are rather the result of dramatic and equally fortunate combinations of events.
HIV, then cancer. The Düsseldorf patient had been declared HIV positive in 2008 and had begun treatment with antiretroviral drugs (the therapies that “chronicize” AIDS, allowing those who are HIV positive to lead a normal life) in 2010. The following year, the The man had fallen ill with leukemia, a blood cancer that he had initially treated with chemotherapy.
In 2013, a relapse of the disease convinced the doctors of the University Hospital of Düsseldorf University to submit the patient to a stem cell transplant: those of the man to be treated, which continued to produce diseased white blood cells, were neutralized with chemo and replaced with those of a donor.
Double healing. And here comes the turning point of the story. Doctors had the opportunity to choose a person with a genetic mutation that made them naturally immune to HIV as a donor, because it disables a receptor (called CCR5) that the virus uses to infect immune cells. With a single, risky transplant, the patient could have recovered from both leukemia and HIV.
And so it was: the man recovered from leukemia and in 2017 he stopped the treatments with immunosuppressants necessary to prevent rejection. In November 2018, the doctors also suspended antiretroviral treatments and today, more than four years later, there are no signs of active infection in his body or of replication of the HIV virus.
Lucky few. The Düsseldorf patient is officially cured as well as four other people who underwent various types of stem cell transplants (patients who remain anonymous and who are known by the name of the hospitals or cities in which they were followed up: City of Hope (Comprehensive Cancer Center, California), London, Berlin, New York.
The list is provisional because it is linked to the years spent free from antiretroviral treatments and the margin of certainty on effective recovery, but the point is that these transplants, which are risky and potentially lethal procedures, are necessary to recover from other diseases – such as cancer – and are not viable as large-scale therapies.
However, they could inspire new treatments: an alternative approach that is being explored is the use of gene editing to alter the CCR5 gene in the immune system of HIV-positive people.