Stem cell therapy for leukemia has been shown to suppress HIV

A team of international doctors has claimed that a stem cell transplant method used for treating leukemia can also suppress HIV-1, the most common cause of AIDS.

The researchers performed an allogeneic hematopoietic stem cell transplant (HSCT) on a patient who suffered from both AIDS and leukemia (blood cancer). This treatment has been able to keep the HIV-1 virus suppressed in the patient for the past nine years. 

For the last four years, the patient has even stopped taking anti-retroviral therapy, which is the regular treatment given to a patient to keep the HIV virus under control. Still, he is able to live a healthy life.

“I was diagnosed with HIV in 2008. Today, I am all the more proud of my worldwide team of doctors who succeeded in curing me of HIV-1 and, at the same time, of course, of leukemia,” said the patient who participated in the study. 

HSCT for long-term HIV suppression 

HSCT is a stem cell therapy that involves the transfer of immature blood-forming stem cells from a healthy person to a patient’s bone marrow whose own stem cells are no longer functional. Apart from resuming normal blood production in the body and treating leukemia, the transferred stem cells also comprise special Δ32 mutations.

These mutations make the cells immune to HIV-1 infection and therefore have the potential to provide remission of both HIV and blood cancer. According to the researchers, the virus count drops down to such levels as a result of the  Δ32 HSCT that it becomes undetectable, and this is what has happened in their patient’s body. 

The patient, who is now 53 years old, underwent HSCT in 2012, and in November 2018, his anti-retroviral therapy was discontinued. Four years have passed since he stopped living on any treatment, and until now, no HIV has been detected in his body. Surprisingly, the leukemia treatment freed him from both blood cancer and HIV-1.

The study authors highlight that this is not the first case of Δ32 HSCT HIV-1 remission. Previously, a patient in Berlin and another in London have experienced similar results after their cancer treatment. However, their research work successfully confirms the long-term (nine years) remission of HIV-1 due to Δ32 HSCT.

Risky but worth trying

One of the major limitations of HSCT is that it’s a high-risk and non-scalable method. The mutation could also lead to viral infections and disorders like Graft vs host disease in the patients. The latter occurs when the stem cells from a donor start attacking the cells in the patient’s body, considering them as foreign material.

The authors believe that “although “HSCT using donors with a CCR5Δ32/Δ32 mutation is neither a low-risk nor an easily scalable procedure.” With further research, it is possible to overcome these limitations and develop effective HIV treatment methods for millions of patients in the future.

“I very much hope that these doctors will now get even more attention for their work. They will certainly hope that their projects will continue to receive financial support so that there can also be an HIV cure without a bone marrow transplant,” said the 53-year-old patient, who is now completely healthy.

The study is published in the journal Nature Medicine.