Cord blood transplantation in children with relapsed or refractory severe aplastic anemia

Early results of cord blood transplantation (CBT) for severe aplastic anemia were poor with a high rate of engraftment failure. We carried out CBT in 5 children with relapsed or refractory severe aplastic anemia, using immunosuppressive preparative regimens. The median time from the diagnosis to the CBT was 16 months (15 to 47 mo), with all the children having failed at least 1 course of immunosuppressive therapy. The conditioning regimens consisted of fludarabine, cyclophosphamide, and antithymocyte globulin. One patient had an HLA-identical sibling donor, and 4 had unrelated donors selected from an NMDP-affiliated cord blood bank. Two patients received double-unit grafts to attain a target TNC dose of at least 3.0×10/kg. Donor/recipient HLA matching was 6 of 6 (n=2) and 5 of 6 (n=5). The median nucleated cell dose infused was 5.6 (range, 3.6 to 6.1) ×10 cells/kg. The median infused CD34 dose was 2.9 (range, 1.8 to 7.5) ×10 cells/kg. All the patients achieved neutrophil engraftment at a median of 13 days (range, 11 to 25 d). The median time to platelet engraftment was 48 days (range, 34 to 56 d). After CBT, acute GVHD developed in 4 cases, CMV reactivation in 1, pneumonia in 1, and sepsis in 1. Four patients successfully engrafted, but 1 failed to engraft and had delayed autologous recovery. However, all patients were now transfusion-independent at the time of reporting. This result suggests that CBT using optimal conditioning regimens can be a salvage treatment for patients without a suitable bone marrow donor and warrants further prospective studies.