Unrelated cord blood transplantation for newly diagnosed patients with severe acquired aplastic anemia using a reduced-intensity conditioning: high graft rejection, but good survival.

We report a single-center experience in treating 18 consecutive patients with severe aplastic anemia (SAA) who received unrelated cord blood transplantation (CBT). The median age was 17 years (range 5-61 years). Sixteen cases received a reduced-intensity regimen composed of CY (total dose 1200 mg/m(2)), rabbit antithymocyte globulin (ATG, total dose 30 mg/kg) and fludarabine (FLU, total dose 120 mg/m(2)). CYA and mycophenolate mofetil were used as GVHD prophylaxis. Two patients were not evaluable for engraftment because of early death on day +21 and +22. Only one of the sixteen cases achieved engraftment, but experienced secondary graft failure 3 months post transplantation. Fifteen patients experienced primary graft rejection, but all of them acquired autologous recovery. The 3-month and 6-month cumulative incidence of response was 56% and 81%, respectively. So far, 16 patients have survived for 330-1913 days (median, 750 days) after transplantation. The probability of OS at 2 years was 88.9%. Our data indicate that CBT for newly diagnosed SAA using no irradiation but FLU and ATG-based conditioning still seems to inevitably lead to the high risk of rejection, but may facilitate autologous recovery and improve survival with low risk of transplant-related mortality.