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Pictured, a laboratory worker preparing equipment used to remove cells that can cause side effects from transplants for blood cancer patients. Image credit: Marijan Murat/picture alliance via Getty Images.
  • Researchers announced on July 27, 2022, that a man has gone into long-term remission of HIV and leukemia after receiving stem cells from a donor with a rare genetic mutation.
  • Of the four people globally who have achieved HIV remission through these transplants, this patient is the oldest and had lived with HIV the longest.
  • The transplant was successful even though the patient underwent a less-intensive pre-transplant regimen due to his age.

A 66-year-old man has achieved long-term remission of HIV 3 years after receiving a stem cell transplant for leukemia, researchers announced on Wednesday, July 27, 2022, in advance of the 24th International AIDS Conferencein Montreal.

Known as the “City of Hope patient” because he underwent treatment at City of Hope, a cancer center in Duarte, California, the man, who has elected to remain anonymous, is only the fourth patient in the world to go into long-term remission following a stem cell transplant.

Of that group, he is the oldest patient and the one who has lived with HIV the longest — he first tested positive in 1988.

“When I was diagnosed with HIV in 1988, like many others, I thought it was a death sentence,” the City of Hope patient says in a statement. “I never thought I would live to see the day that I no longer have HIV.”

The City of Hope patient underwent a stem cell transplant more than 3 years ago. Figuring out whether the procedure had led to HIV remission did not happen overnight, according to Dr. John Zaia, director of the Center for Gene Therapy at City of Hope and one of the practitioners who cared for the patient.

“For a while, you’re just waiting, because you’re hoping that the transplant affected that leukemia, that everything is going well,” Dr. Zaia explained to Medical News Today in an interview.

“And during that time, the person is on anti-HIV meds, so HIV is under control and you’re wondering whether you can justify recommending to the person to stop his meds,” he added.

About 2 years after the transplant, Dr. Zaia said, doctors no longer saw evidence that the patient had replicating HIV virus. “At that point, we all agreed it would be ethical to ask him if he wanted to stop his therapy or not, and he did.”

Two infectious disease experts contacted by MNT stopped short of calling news that a fourth person is in long-term remission from HIV following a stem cell transplant a scientific milestone.

“It has very limited implications for the general world,” Dr. William Schaffner, professor of medicine in the division of infectious diseases at the Vanderbilt University School of Medicine in Nashville, Tennessee, told MNT.

Currently, experts say stem cell transplants are too risky to be considered for HIV patients — unless the individual also needs to be treated for a possibly fatal cancer.

“It’s a very elaborate procedure,” Dr. Schaffner said of stem cell transplants. “It is dangerous in and of itself […] this is not something that can be applied to large numbers of people.”

Dr. Otto Yang, professor of medicine in the division of infectious diseases at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA), and associate director of UCLA’s AIDS Institute, agreed during an interview with MNT that having a fourth person in remission following a stem cell transplant is not a game changer for HIV researchers, although it is a happy development for the City of Hope patient personally.

“I mean, obviously, it’s great, right?” Dr. Yang said. “It’s good news, but it’s not new news.”

The first person who went into long-term remission for HIV following a stem cell transplant was an individual initially referred to as the Berlin patient. Timothy Ray Brown later identified himself.

His donor, like the donors in all four cases, had a rare genetic mutation that made him immune to HIV. When Brown died in 2020 due to recurring leukemia, he was reportedly still in remission from HIV.

“This, basically, is almost an exact duplication of the story of the Berlin patient,” Dr. Yang told MNT.

In 2020, an individual known as the “London patient” who had HIV was treated with a stem cell transplant to treat Hodgkin lymphoma and became the second person to go into long-term remission of HIV. As with the Berlin patient, his doctors also used cells that did not express CCR5 Delta 32. Individuals with that mutation are resistant to acquiring HIV.

“That mutation is basically a mutation in one of the main receptors that HIV needs to get inside the cell,” Dr. Yang explained.

This February, specialists at Weill Cornell Medicine in New York City announced that an HIV-positive woman had received a stem cell transplant to treat leukemia, which also led to long-term remission of HIV.

There is a reason why there have only been four patients who achieved long-term HIV remission following a stem cell transplant over 15 years, according to Dr. Yang.

In addition to the procedure being dangerous, it is difficult to find donors who have the CCR5 mutation, he noted. “Unfortunately, there are a lot of barriers to this being a routine treatment,” he explained.

Dr. Yang added that the City of Hope patient does illustrate that long-term HIV remission can be achieved. “The good thing is that it does show once again, that it wasn’t a fluke,” he told MNT. “That it is achievable.”

One thing that sets this fourth patient apart, according to Dr. Zaia, is that due to his age he received reduced-intensity chemotherapy prior to his transplant. “This was an older patient, and we have a gentler regimen for treating the elderly,” Dr. Zaia told MNT.

“It’s the first time that a person got this kind of treatment. That shows you that you don’t need to just destroy the entire system of immune cells to get rid of the virus.”

– Dr. John Zaia

Knowing this type of stem cell transplant works is important because people living with HIV are living longer thanks to antiretroviral therapy.

“As the HIV-positive community becomes more elderly, they will acquire more cancers,” Dr. Zaia said. “And this method could be used in those people rather than having to use harsher treatment.”

The success of the City of Hope patient is also important because it encourages the scientific community to keep pushing, Dr. Zaia pointed out.

If scientific advances continue to make stem cell transplants safer and easier, more people with HIV could receive the treatment.

“It’s still not likely to be the answer for curing the world’s population of HIV-positive people, but it’ll probably have a role,” Dr. Zaia said.