Adult T-cell Leukemia/lymphoma in Sustained Complete Response Six Years After Allogeneic Stem Cell Transplantation From a Related Htlv-1-positive Donor: a Case Report
Year: 2026
Type: article
Study design: Case Report
Abstract: Background Adult T-cell leukemia/lymphoma (ATLL), lymphomatous subtype, is an aggressive HTLV-1-associated malignancy with high relapse rates and poor survival. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only strategy with curative potential in eligible patients. Case report We report a previously healthy 48-year-old woman diagnosed in 2019 with lymphomatous-subtype ATLL, who achieved complete response after 2 cycles of CHOEP chemotherapy. She underwent allo-HSCT from a fully HLA-matched (100%) related donor, male, also HTLV-1 positive. Peripheral blood stem cells were infused on 02/06/2020, with neutrophil engraftment on D+11; early post-transplant toxicities were manageable. Serial follow-up confirmed complete metabolic response by PET-CT, full donor chimerism, and negative minimal residual disease, with sustained remission for over six years to date. She remains in follow-up with chronic GVHD involving lungs, eyes, and oral mucosa, adequately controlled. Ibrutinib was used from August 2021 until April 2026, when therapy was switched to ruxolitinib due to progression of pulmonary and ocular GVHD. Discussion ATLL remains challenging even with conventional chemotherapy, and allo-HSCT offers the best chance of durable survival and cure. A recent EBMT Lymphoma Working Party analysis of 73 ATLL patients reported a 2-year overall survival of 49%, with complete response at transplant, younger age, and haploidentical donor identified as independent predictors of improved outcome. Our patient met two of these criteria, complete response and younger age, though her donor was fully HLA-matched rather than haploidentical, showing that favorable outcomes are achievable outside this subgroup. A distinctive feature of this case is the use of an HTLV-1-positive related donor, uncommon in the allo-HSCT literature and particularly relevant in HTLV-1-endemic regions where donor availability may be limited. Sustained remission without graft failure or donor-derived complications supports the feasibility of this strategy when no better-matched alternative exists. Conclusion This case reinforces allo-HSCT as a potentially curative strategy in lymphomatous ATLL, highlights the challenges of long-term chronic GVHD management, and demonstrates durable survival with preserved quality of life, including in the setting of an HTLV-1-positive related donor.
Institution: Hospital Santa Izabel
Language: English
Subfield: Immunology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7223096997