Immunosuppressive Total Lymphoid Irradiation-Based Reconditioning Regimens Enable Engraftment After Graft Rejection or Graft Failure in Patients Treated With Allogeneic Hematopoietic Stem Cell Transplantation

Purpose: To retrospectively evaluate the efficacy of total lymphoid irradiation (TLI)-based reconditioning regimens in patients with graft failure or graft rejection after allogeneic hematopoietic stem cell transplantation. Methods and Materials: The results of 14 patients (7 adults and 7 children) with a variety of hematologic malignant diseases treated with a TLI-based reconditioning regimen with 7-Gy single-dose application plus anti-T-lymphocyte antibody OKT3 (n = 11) and/or antithymocyte globulin (n = 7)/fludarabine (n = 9), followed by an infusion of peripheral blood stem cells (n = 13) or bone marrow stem cells (n = 1) from related or unrelated donors, were retrospectively analyzed. Results: Of the 14 recipients, the data from 11 were evaluable for engraftment after TLI-based reconditioning because 3 adults died early (at Day 2, 5, and 15) after the second transplantation of infectious complications. Engraftment in 4 adults was seen after a median of 12 days (range, 10-18) and occurred after a median of 10 days (range, 9-32) in the 7 children. TLI-based reconditioning was well-tolerated with no severe toxicity. The median overall survival and disease-free survival for the whole cohort was 140 days (range, 5-1,268). After a median follow-up of 681 days, the disease-free survival and overall survival rate was 85.7% and 85.7%, respectively, in the children. Despite engraftment in the 4 remaining adults, 1 died of fatal graft-vs.-host disease, 1 of infectious complications, 1 of disease relapse, and 1 of acute respiratory distress syndrome. Conclusions: In patients with graft failure or graft rejection after allogeneic hematopoietic stem cell transplantation, TLI-based reconditioning regimens allow sustained engraftment, paralleled by a favorable toxicity profile, potentially leading to long-term survival