Allogeneic Hematopoietic Stem Cell Transplantation Using Reduced-Intensity Conditioning in the Patients with Acute Leukemia

Allogeneic hematopoietic stem-cell transplantation (HSCT) following myeloablative regimens has been used to treat patients with acute leukemia. Reduced-intensity conditioning (RIC) has been developed for older patients which are associated with a high risk of transplant-related mortality (TRM). We investigated the outcomes of allogeneic HSCT with RIC in the patients of acute leukemia.

Among the patients with acute leukemia who have received allogeneic HSCT in Ewha Womans University Hospital between 1998 and 2010, outcomes of the patients who received HSCT with RIC were analyzed retrospectively.

Twenty-two patients were enrolled in this study including 8 patients of acute lymphoblastic leukemia (ALL) in first complete remission (CR), 14 patients of acute myeloid leukemia in first CR (n=9), second CR (n=2), and not in CR (n =3). Seventeen patients with hematopoietic cell transplant comorbidity index score 0 were included in this analysis. Twelve patients received fludarabine (150mg/m²) with melphalan (140mg/m²), and 10 patients received fludarabine (150mg/m²) with busulfan (6.4mg/m²) as conditioning regimen, and followed by transplantation from matched sibling (n=16), unrelated donors (n=5), or unrelated cord blood (n=1). All patients received graft-versus-host disease (GVHD) prophylaxis with methotrexate and cyclosporine (n=18) or FK506 (n=3) except one patient who received cyclosporine alone. Cumulative incidence of grade 2–4 acute and chronic GVHD were 18.2% and 45.5%. Donor chimerism in bone marrow at 30 day and in blood at 100 day were median 99.0% and 97.0% after HSCT. Rates of relapse was 22.7% after median 7.5 months of follow-up. Non-relapse mortality at 100 day and 1 year were 13.6% and 27.3%. Disease-free survival and overall survival were median 33.0 month and 42.7 month by Kaplan-Meier analysis.

These results suggest that allogeneic HSCT using RIC for treatment of acute leukemia may be a potential therapeutic approach considering less toxic and acceptable treatment outcomes even in young adult ALL without comorbidity which has not been previously considered as candidate of allogeneic HSCT using RIC.

No relevant conflicts of interest to declare.