Scientists say they may have cured the first woman of HIV, which would make her the fourth person ever to be cured of the virus. The “New York patient” received a cutting-edge stem cell technique that could soon be available to hundreds of patients.
The Ups and Downs of Treating HIV
The first person to be cured of HIV was Timothy Ray Brown, who was also being treated for acute myeloid leukemia, or AML. He received stem cells from a donor who had a genetic abnormality with immune cells that were naturally immune to the virus. The case was first made public in 2008. Since then, the treatment successfully cured two more men of HIV, but it also failed in others.
Despite these setbacks, Carl Dieffenbach, director of the Division of AIDS at the National Institute of Allergy and Infectious Diseases, one of multiple divisions of the National Institutes of Health that funded the research behind the new case study, said the latest success “continues to provide hope” to people living with HIV.
The treatment is designed to replace the patient’s immune system with healthy cells that can help fight off their cancer and HIV. The doctors must first destroy the patient’s existing immune system with irradiation and chemotherapy while also targeting cells that may contain the virus. The patient then receives a stem cell transplant. If the cells engraft properly, any remaining HIV cells will not be able to infect the new immune cells.
Stem cell transplants can be fatal, which is why providers say it would be unethical to use it on anyone that’s not suffering from a potentially fatal condition like cancer.
Dr. Deborah Persaud, a pediatric infectious disease specialist at the Johns Hopkins University School of Medicine who chairs the NIH-funded scientific committee behind the new case study, said that “while we’re very excited” about the new case of possible HIV cure, the stem cell treatment method is “still not a feasible strategy for all but a handful of the millions of people living with HIV.”
The woman in question was diagnosed with HIV in 2013 and leukemia in 2017.
Persaud and her colleague Dr. Yvonne J. Bryson, a pediatric infectious disease specialist at UCLA’s David Geffen School of Medicine, have been running lab tests on the woman as she recovers.
To conduct the clinical trial, researchers had to find a donor with stem cells that could treat the patient’s cancer and cure their HIV.
Typically, the donor must have a similar human leukocyte antigen, or HLA, as the patient to increase the chances of the stem cells engrafting well. The donor must also have a rare genetic abnormality conferring HIV resistance. The abnormality tends to be most common in people from Northern Europe, but it has only been found in 1% of the local population, which makes it extremely difficult to find a donor.
The Haplo-Cord Transplant
The treatment consists of what’s known as a haplo-cord transplant. It was first developed by researchers at Weill Cornell. The patient receives a transplant of umbilical cord blood, which contains stem cells that amount to a powerful nascent immune system. The next day, the patient receives adult stem cells, which slowly evolve into cord blood cells over time.
“It would’ve been very difficult to find a match plus this rare mutation unless we were able to use cord blood cells,” Dr. Bryson. “It does open up this approach for a greater diversity of population.”
Cord blood is more adaptable compared to adult stem cells. It requires less of HLA match for the stem cells to engraft properly, which increases the chances of success. However, umbilical cord blood doesn’t usually yield enough cells to complete a successful transplant, which is why adult stem cells are needed.
“The role of the adult donor cells is to hasten the early engraftment process and render the transplant easier and safer,” said Dr. Koen van Besien, one of the experts involved in the study.
“We estimate that there are approximately 50 patients per year in the U.S. who could benefit from this procedure,” van Besien said of the haplo-cord transplant’s use as an HIV-cure therapy. “The ability to use partially matched umbilical cord blood grafts greatly increases the likelihood of finding suitable donors for such patients.”
The woman’s transplant engrafted very well. She has been in remission from her leukemia for more than four years. Three years after her transplant, she and her clinicians discontinued her HIV treatment. Fourteen months later, the virus is still in remission.
“You don’t want to over-call it,” Bryson said of using the word “remission” over “cure” at this stage.
“I’m excited that it’s turned out so well for her,” Bryson added. The apparent success has given researchers “more hope and more options for the future.”
