Reduced Intensity T-Replete Allogeneic Stem Cell Transplantation Provides Long-Term Survival in Relapsed Angioimmunoblastic T-Cell Lymphoma Post-Autologous Transplant in patients over the age of 50

Background Relapsed angioimmunoblastic T-cell lymphoma (AITL) following autologous transplantation carries poor prognosis. Reduced-intensity T-replete allogeneic transplant may provide durable disease control via immune-mediated graft effects. Methods We retrospectively analyzed 21 patients over the age of 50 with relapsed AITL who underwent reduced-intensity T-replete allo-HCT across three transplant centers between 2013 and 2022. Following salvage treatment, all patients experienced chemo sensitive disease and proceeded to transplantation. Responses were PET-based, and survival outcomes were assessed. Results All patients achieved hematologic engraftment, with 13 in complete metabolic remission and 8 in partial remission at the time of transplant. At a median follow-up of 7.55 years, OS was 100%, 81%, and 71% at 1, 2, and 5 years, respectively, with PFS of 95%, 95%, and 84%. Seven deaths occurred, four due to disease progression and three related to transplantation. Acute and chronic GvHD were observed in 30% and 22% of patients respectively. Five patients received donor lymphocyte infusion, showing a trend toward improved survival. Conclusion Reduced-intensity T-replete allo-HCT is a feasible and potentially curative therapeutic option for patients over 50 with chemo sensitive relapsed AITL after autologous transplantation. Early disease control and long-term remission suggest a clinically meaningful graft-versus-lymphoma (GVL) effect in appropriately selected individuals.