Man remains in treatment-free HIV remission after stem cell transplant
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Key takeaways:
- A man has remained in HIV remission without ART after receiving a stem cell transplant.
- Unlike similar cases, the stem cells came from a donor who lacks a genetic mutation that makes people resistant to HIV.
A man has remained in treatment-free HIV remission for nearly 2 years after receiving a stem cell transplant to treat a rare and aggressive form of leukemia, researchers reported Wednesday.
It is the latest example of a person who has potentially been cured of HIV after receiving someone else’s stem cells — although this case comes with a twist.
Unlike the handful of people who have been cured of HIV after receiving stem cells from donors who harbor a rare genetic mutation that makes them naturally resistant to HIV, this transplant came from a donor who did not have that mutation, called CCR5-delta 32.
Details of the “Geneva patient” — as he is being called — were reported by researchers on the eve of the biennial International AIDS Society (IAS) conference, which begins Sunday in Brisbane, Australia.
The patient, described by researchers as a white man in his early 50s, was diagnosed with HIV in 1990 and had been virally suppressed on ART for 13 years in 2018, when he received chemotherapy and an allogeneic hematopoietic stem cell transplantation at a hospital in Geneva to treat a biphenotypic sarcoma.
The stem cells were from a donor with a “wild-type” CCR5 gene — in other words, they did not possess the genetic mutation that knocks out the CCR5 receptor that HIV uses to enter human cells.
The man discontinued ART fully in November 2021 and has maintained an undetectable viral load for 20 months without treatment, the researchers reported.
“We consider this person [to be] in viral remission,” Asier Sáez-Cirión, PhD, head of the viral reservoirs and immune control unit at the Pasteur Institute in Paris, said during a press briefing, although Sáez-Cirión told reporters they cannot guarantee there is no HIV remaining in the man’s body.
“There may be viral rebound in the future, although we hope that this situation of viral remission remains permanent,” he said.
The case resembles the “Boston patients” — two people with HIV who achieved remission a decade ago after receiving stem cells from donors without the CCR5 mutation. HIV rebounded in both of those patients after 4 and 8 months, according to IAS president Sharon Lewin, MBBS, PhD, who runs the Peter Doherty Institute for Infection and Immunity in Melbourne.
“In this new case, the patient has already achieved far longer durable HIV remission without treatment,” Lewin told reporters. “This is promising, but we learned from the Boston patients that even a single virion can lead to viral rebound ... and this particular individual will need to be watched closely over the next months to years.”
Questions also remain about whether other factors have contributed to keeping him virally suppressed in the absence of ART.
For instance, the man developed chronic graft-versus-host disease and was treated with the immunosuppressive drug ruxolitinib, which may have had an impact on reducing his HIV reservoir and staving off viral rebound, said another one of the researchers, Alexandra Calmy, MD, PhD, who heads the HIV/AIDS unit at the University Hospital of Geneva.
“This is a drug that has been shown to be able to repress the reservoir in vitro ... and is among the possibilities of what may be different in this case,” Sáez-Cirión said.
Lewin said each reported case of long-term HIV remission without ART following a stem cell transplant has its own peculiarities that may enlighten HIV cure research, but that no one case is likely to solve the puzzle by itself.
“In medicine, we always talk about the anecdote, the clinical anecdote that leads to new ideas. Case reports are similar,” Lewin said. “Maybe there is something different specifically about the Geneva patient ... but ultimately, we will always need a randomized clinical trial to understand whether a particular intervention works.”
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Sáez-Cirión A, et al. Abstract 5819. Presented at: International AIDS Society Conference on HIV Science; July 23-26, 2023; Brisbane, Australia.
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