A Norwegian man has entered long-term remission from HIV after a rare stem cell transplant, adding to a small but growing number of similar cases worldwide.
A study published April 13 in Nature Microbiology details the case of a 63-year-old man, known as the “Oslo patient,” who continues to show no detectable signs of the virus years after undergoing a high-risk stem cell transplant.
Researchers reported that the patient remains in remission five years after receiving an allogeneic hematopoietic stem cell transplant from his brother, who carried a rare genetic mutation known as CCR5Δ32. That mutation prevents HIV from entering immune cells, effectively blocking the virus’s ability to replicate.
According to the study, the patient stopped antiretroviral therapy two years after the procedure. Four years later, extensive testing found no intact HIV DNA in his blood or gut tissue, and no replication-competent virus could be detected. The patient has now gone more than three years without treatment and without any viral rebound.
“For all practical purposes, we are quite certain that he is cured,” lead author Anders Eivind Myhre said, according to remarks reported by Agence France-Presse.
The case is one of only a handful worldwide in which HIV has gone into long-term remission following a stem cell transplant. Previous cases include patients in Berlin, London, and New York, among others, who underwent similar procedures typically to treat life-threatening blood cancers.
The Norwegian patient originally received the transplant to treat myelodysplastic syndrome, a serious bone marrow disorder. Doctors initially struggled to find a suitable donor with the CCR5Δ32 mutation, which is found in roughly 1% of people of Northern European descent. The patient’s brother was ultimately selected as a donor match, and only on the day of the transplant did doctors discover he carried the mutation.
“We had no idea… That was amazing,” Myhre said, according to AFP.
Researchers said the patient achieved “full donor chimerism,” meaning his immune system was effectively replaced by his brother’s cells. Notably, the study found this replacement extended to the gut, a major reservoir where HIV typically persists even under long-term treatment.
Researchers cautioned that the procedure is not a practical cure for the millions of people living with HIV globally. Stem cell transplants carry significant risks, including graft-versus-host disease and life-threatening infections, and are generally reserved for patients with serious cancers.
The Norwegian patient himself experienced complications, including graft-versus-host disease and viral infections, during recovery.
Still, scientists say such cases offer critical insight into how HIV might one day be eradicated more broadly.
The study noted that while most successful cases involve donors with the CCR5Δ32 mutation, some patients have achieved remission without it, suggesting additional biological mechanisms may play a role.
The patient, who was diagnosed with HIV in 2006, is now described as being in good health and living without ongoing treatment. One researcher suggested the label “patient” may no longer apply.
“The Oslo patient is perhaps no longer a patient. At least he doesn’t feel like it,” co-author Marius Trøseid said, according to AFP.
Health authorities estimate that nearly 41 million people worldwide are living with HIV, underscoring the significance of research into potential cures, even if current methods remain limited to rare and complex cases.