A European man has reportedly been in remission from HIV for two years, following a stem cell transplant to treat blood cancer.
Confirmation would make him the sixth person in history to become HIV-free.
Unlike the other five people who have achieved HIV remission through stem cell transplants, the donor for this unidentified patient did not have a genetic abnormality that creates a resistance to the human immunodeficiency virus, according to NBC News.
If this man — who has been dubbed the “Geneva patient” after being treated in the Swiss city — is in remission long enough, he could be considered potentially cured of HIV.
“The possibility of viral rebound is indeed a concern,” Asier Sáez-Cirión, who is leading the research team following the anonymous patient, told NBC News. “The virus may persist in rare infected blood cells or anatomical sites that we have not analyzed.”
Despite multiple attempts to find a cure for the virus — which advances to AIDS in its final, lethal stage — HIV remains incredibly difficult to cure due to its ability to hide dormant in the cells, known as latency.
The standard treatment utilizes antiretroviral treatments (ART), which reducess the amount of the virus in the body, otherwise known as the viral load. These medications lower the risk of transmitting the virus to others as well.
Only five individuals have been confirmed to be definitely or possibly cured of HIV, since 2008, when Timothy Ray Brown, the Berlin Patient, underwent stem cell transplants that treated both his HIV infection and leukemia.
Brown, who died in 2020 after leukemia returned, was the first patient to be cured of the potentially fatal virus.
The Geneva Patient, who is in his early 50s, has gone 20 months with no viral rebound, per NBC News, and stopped antiretroviral treatment in November 2021.
Now, he’s being monitored by Sáez-Cirión, the head of the viral reservoirs and immune control unit at the Institut of Pasteur in Paris, and his team.
Through ultrasensitive tests to detect HIV, the researchers have only found trace amounts, but cannot eliminate the possibility of the virus returning. Even one infected cell could result in a viral rebound.
The patient was first diagnosed with HIV in 1990 and began antiretroviral treatment in 2005, according to NBC News, but only received a stem cell transplant after being diagnosed with a rare blood cancer, an extramedullary myeloid cell tumor, in 2018.
It’s possible that the immunosuppressive drugs the patient consumes to prevent graft-versus-host disease — the donor graft’s rejection of the host — could be key in suppressing the virus, Sáez-Cirión said.
Yet, the man’s success thus far remains a mystery for now, as experts can’t pinpoint why the Geneva Patient’s treatment saw promising results.
Historically, patients who are potentially cured of HIV through stem cell transplants receive cells that contain a genetic mutation that is resistant to infection — but the Geneva Patient did not receive mutated cells.
His case is slated to be presented in the coming days at the International AIDS Society Conference on HIV Science, held in Brisbane, Australia, NBC News reports.
The case’s findings are “great news” and could “help in many ways in the work toward a cure,” IAS President Dr. Sharon Lewin told the outlet.
While supposedly an effective treatment for HIV, stem cell transplants are typically reserved for patients who have certain cancers and carries an array of side effects and health risks.
Recently, Paul Edmonds became the oldest person cured of HIV at 66, after a bout with leukemia and receiving a stem cell transplant from a donor with an HIV-resistant gene mutation.
His “amazing” journey follows the successful treatment of an anonymous German man who was declared HIV-free this year after entering remission in 2019.
Last year, the first woman, and also the third person, was reported to be cured of the virus after receiving a novel umbilical cord blood transplant.