[Non-myeloablative stem cell transplantation for non-malignant hematologic disorders].

Although non-myeloablative stem cell transplantation(NST) was originally developed to induce graft-versus-malignancy effect, the new transplant modality is now being applied for treatment of non-malignant disorders such as aplastic anemia(AA) and paroxysmal nocturnal hemoglobinuria due to its low toxicities. NST may be preferable than conventional transplantation when an AA patient has complications due to hemochromatosis such as heart failure and diabetes mellitus, and severe infections. We treated three aplastic anemia patients complicated by various organ failures, with a conditioning regimen consisting of fludarabine (Flu), cyclophosphamide(CY), and antithymocyte globulin (ATG). Engraftment promptly occurred in all patients without accompanying severe graft-versus-host disease or organ damages. Successful induction of complete chimerism and a low incidence of toxicities warrant a further clinical trial using the Flu + CY + ATG regimen.