Pentotstatin/Tbi Conditioning Is Well-Tolerated And Permits Engraftment Of A Second Allogeneic Stem Cell Transplant Following Primary Or Secondary Rejection Of An Allogeneic Hematopoietic Stem Graft

Introduction: Graft failure remains a major obstacle to the success of allo-HSCT. Rates of graft failure are reported to be 2% in recipients of HLA identical grafts, 9% in those with an unrelated donor, and up to 12.3% in those with an HLA-mismatched related donor (0-3 antigen mismatched). Graft failure is associated with high mortality due to prolonged cytopenia's leading to significant anemia, bleeding, and infection. Successful management of graft failure usually requires a second transplant to restore normal hematopoiesis. The selection of a preparative regimen presents a challenge in these patients who have recently undergone myelosuppressive therapy prior to the failed transplant maneuver. We have employed the use of a minimally myelosuppressive regimen consisting of a single dose of pentostatin with a low dose of total body irradiation (TBI) as conditioning prior to a second allogeneic transplant for patients who experienced primary graft rejection.