Man Remains HIV-Free Years After Stem Cell Transplant, Offering New Insights into Potential Cure
Berlin, Germany – A 60-year-old man is still free of HIV years after undergoing a stem cell transplant for acute myeloid leukemia, a case offering renewed hope for a functional cure for the virus. The remarkable outcome suggests the donor’s immune system actively eliminated residual HIV from the patient’s body, even though the donor was not a perfect match for the CCR5-Δ32 genetic mutation known to confer HIV resistance.
The CCR5 gene provides instructions for making a protein that acts as a major docking point for HIV on immune cells. The CCR5-Δ32 mutation, when present on both chromosomes (homozygous), prevents the formation of these receptors, effectively blocking viral entry. While the “Berlin patient” achieved a well-documented cure following a transplant from a homozygous donor,finding such a match is rare.
In this recent case, no suitable homozygous donor was available, and the patient received a transplant from a heterozygous donor – meaning they carried one copy of the CCR5-Δ32 mutation. While heterozygosity only slows viral progression, the patient has remained HIV-free for years following the transplant.
Initially, the patient had lived for five years without antiretroviral therapy after discovering his HIV infection in 2009, but his condition later deteriorated. The stem cell transplant, a risky procedure typically reserved for cases where conventional cancer treatments fail, was undertaken as a treatment for his leukemia.
Researchers believe the donor’s immune system played a crucial role in eradicating the virus. Preliminary findings indicate the patient’s natural killer cells now exhibit a unique profile.This case strengthens the potential for specially adapted immunotherapies and stem cell gene therapy to offer a cure for many living with HIV.
The findings were recently published in Nature (Gaebler, C. et al., Nature, 10.1038/s41586-025-09893-0, 2025).
