New Report of HIV Remission After Stem Cell Transplant

Another patient appears to have achieved long-term, treatment-free HIV remission after an allogeneic stem cell transplant (allo-SCT), according to findings published Dec. 1 in Nature. Unlike previous cases, however, the stem cell donor was only heterozygous for the rare genetic mutation previously thought to be essential for an HIV cure.

In most previous cases, patients received stem cells from donors with a rare CCR5 Delta 32 mutation, present in about 1% of the European population. The CCR5 receptor is a protein on the surface of immune cells that HIV uses to enter and infect the cells. Individuals who inherit two copies of the CCR5 Delta 32 mutation have a defective receptor, which prevents HIV from entering cells, effectively conferring immunity.

In the current case, a male patient living with HIV carried one normal CCR5 gene and one Delta 32–mutated CCR5 gene. He received an allo-SCT from an HLA-matched unrelated donor, also heterozygous for Delta 32–CCR5, as treatment for acute myeloid leukemia. Three years after the procedure, he discontinued antiretroviral therapy and has maintained remission for more than six years with undetectable plasma HIV RNA.

Investigators noted that high antibody-dependent cellular cytotoxicity at the time of transplantation may have helped eliminate the patient’s HIV reservoir, underscoring the potential role of viral reservoir reduction in achieving durable remission.