A study published on Monday in Nature Microbiology confirms long-term HIV remission in the «Oslo patient», a 62-year-old man treated for myelodysplasia via stem cell transplant from his brother carrying the CCR5 Delta 32 mutation. He has been off antiretrovirals for four years with no detectable virus. This brings the total to ten patients deemed cured this way.
The international IciStem consortium, coordinated by IrsiCaixa, details the Oslo patient's case in the journal. Javier Martínez-Picado, a researcher at IrsiCaixa and co-leader of the project, states: «At first they said cure was impossible [...]. But 10 patients later, we know it is possible to cure [HIV infection] and now we must see how to make it scalable».
The pioneer was Timothy Brown, the Berlin patient, cured of HIV and leukemia in 2009 via a transplant from a CCR5 Delta 32 donor selected by hematologist Gero Hütter. Brown died in 2020 from cancer relapse but free of HIV. Other cases include London patient Adam Castillejo, HIV-free for nearly ten years.
The procedure uses chemotherapy to destroy infected cells and tumor marrow, followed by transplant of HIV-resistant cells due to the mutation blocking viral entry. Martínez-Picado notes donor allogeneic immunity is key to clearing the viral reservoir, with the mutation as a bonus. IciStem monitors 40 transplanted patients, not all with mutated donors.
While the double CCR5 Delta 32 mutation boosts chances, exceptions exist like the Geneva patient cured without it. Experts warn transplants are high-risk and limited to blood cancers. Martínez-Picado stresses: «The solution to HIV is not transplantation». These cases spur research like CAR-T therapies at IrsiCaixa led by María Salgado, and gene editing.
