The efficacy of unrelated cord blood transplantation for adult myelodysplastic syndrome

Abstract

Although allogeneic stem cell transplantation from a human leukocyte antigen (HLA)-identical related donor offers a potential cure for patients with myelodysplastic syndrome (MDS), a suitably matched related donor is unavailable for approximately two thirds of patients. Recently, umbilical cord blood from unrelated donors have been used as an alternative stem cell source for adult patients with MDS. Here, we updated the results of unrelated cord blood transplantation (CBT) after myeloablative conditioning for 22 adult patients with MDS. Diagnosis at transplantation included refractory anemia (RA) (n = 3), refractory anemia with excess blasts (RAEB) (n = 2), RAEB-t (n = 2), and MDS-related secondary acute myeloid leukemia (AML) (n = 15). All patients were treated with total body irradiation (12 Gy), cytosine arabinoside (Ara-C) and cyclophosphamide followed by unrelated HLA-mismatched CBT. The median age was 40 years (range, 19 – 51 years), the median weight was 54.5 kg (range, 43 – 75 kg), and the median number of cryopreserved nucleated cells was 2.43 × 10⁷/kg (range, 1.82 – 4.10 × 10⁷/kg). Twenty one patients had myeloid reconstitution and the median time to more than 0.5 × 10⁹/l absolute neutrophil count was 22.5 days. A self-sustained platelet count more than 50 × 10⁹/l was achieved in 19 patients at a median time of 49 days. Acute GVHD above grade II occurred in seven of 21 evaluable patients and chronic GVHD in 16 of 19 evaluable patients. Among 16 chronic GVHD patients, in eight patients the disease was extensive. Seventeen patients are alive and free of disease at between 371 and 2562 days after transplantation. With a median follow-up of 1505 days, the probability of disease-free survival at 4 years was 76.0%. These results suggest that adult MDS patients without suitable related or unrelated bone marrow donors should be considered as candidates for CBT.

Keywords:

• Myelodysplastic syndrome
• cord blood transplantation
• myeloablative conditioning
• adult