Another patient with HIV has remarkably gone into remission after receiving stem cell transplantation 10 years ago for leukemia, making him one of only a tiny number to have been effectively cured of HIV. Following a bone marrow transplant in 2013, the 53-year-old man now has no detectable HIV within his blood and stopped all treatment for the disease in 2018, suggesting the high-risk procedure could be an option to treat HIV.
“This study shows that transplanting blood stem cells from an HIV-resistant donor has led to the development of a new, HIV-resistant immune system in an HIV+ patient,” said Dr Ioannis Jason Limnios, a researcher at the Clem Jones Centre for Regenerative Medicine at Bond University who was not involved in the study, in a statement.
“By following the patient for a decade after transplantation, researchers have shown that their HIV resistant immune system is stable and working well, and that the patient remains healthy after stopping antiviral therapy for 4 years.”
There have been two key pieces of previous scientific evidence that point to stem cell transplants curing HIV, dubbed the “London patient” and the “Berlin patient”. Both people received hematopoietic stem cell transplantation (HSCT) and were subsequently declared clear of the virus, which was previously thought to be incurable with modern medicine. As such, therapies against HIV are either preventative or suppressive – there are currently no other ways to entirely remove the virus from circulating blood.
Enter a 53-year-old man in good health, other than a HIV diagnosis which was managed in the standard way. In 2011, he received a devastating acute myeloid leukemia diagnosis and required a bone marrow transplant, an extremely risky procedure that requires almost total suppression of the immune system as new stem cells are transplanted into the recipient. The idea is to replace the old, “faulty” immune system and rebuild it with donor cells in a way that does not result in tumors.
However, after he recovered from the surgery and continued the standard HIV treatment, which was expected to be taken for life, the doctors noticed that there were no circulating pro-viral HIV-1 particles in his blood. With his consent, antivirals were stopped almost six years after the surgery and he was closely monitored to see if the HIV would return.
Remarkably, no HIV mRNA or replicating particles were found in his blood even after stopping treatment. Incredibly detailed analysis found some lingering HIV DNA, but it was not replicating or posing any threat to his body. There were some small reservoirs of the virus within some tissues, indicating it may never be fully gone, but his immune system had stopped attempting to fend off the virus, deciding it was no longer a threat with the essentially zero presence left in the blood.
He now marks one of only a handful of recorded cases of people being functionally cured of HIV, adding further evidence for the use of HSCT as a therapy against HIV and AIDS.
“Over the past 10 years, stem cell and gene editing technologies (such as CRISPR) have advanced medical science to a point where we can now engineer stem cells for such therapies. Rather than harvesting stem cells from donors with rare and special genetics, they can be created in specialised facilities under highly controlled conditions, and in greater quantities,” continued Dr Limnios.
“This is important and exciting progress in the fight against AIDS, however, the researchers carefully state that HIV remains hidden in other tissues of the body. So, it’s not yet clear if type of therapy is a life-long “cure,” and the risk of passing on HIV, whilst extremely low, will never be zero using this therapy alone."
The research is published in Nature Medicine.