Long-term HIV-1 remission achieved through allogeneic haematopoietic stem cell transplant from a CCR5Δ32/Δ32 sibling donor

Only few cases of human immunodeficiency virus (HIV) remission have been reported after allogeneic haematopoietic stem cell transplantation (HSCT), mostly involving stem cell donors with the homozygous CCR5Δ32 (CCR5Δ32/Δ32) mutation, which confers resistance to CCR5-tropic HIV-1. Here we report the case of a 63-year-old man in off-treatment HIV remission, 5 years after HSCT with a CCR5Δ32/Δ32 sibling donor for myelodysplastic syndrome. In-depth clinical characterization including virological and immunological analyses of peripheral blood, gut and bone marrow samples revealed that full donor chimerism was achieved. Antiretroviral therapy was discontinued after 24 months, and 48 months after HSCT, no intact HIV DNA was detected in blood or gut biopsies. Replication-competent virus and HIV-specific T cell responses were absent, and HIV antibody responses showed a gradual decline. Full donor chimerism in the gut, which is the primary viral reservoir, underscores the likelihood of a cure. This case study reports human immunodeficiency virus remission without antiretroviral treatment in an individual who received an allogeneic haematopoietic stem cell transplantation from a sibling donor with a homozygous CCR5Δ32 mutation.