Graft failure in cord blood transplantation successfully treated with short-term reduced-intensity conditioning regimen and second allogeneic transplantation.

Graft failure (GF) remains a major problem in cord blood transplantation (CBT). In 36 adult patients undergoing CBT at our hospital between July 2003 and December 2009, six patients developed GF (primary, n = 5; secondary, n = 1). All six patients underwent second stem cell transplantation (SCT). Three patients had acute myeloid leukemia, one had acute lymphoblastic leukemia, one had chronic myeloid leukemia, and one had aplastic anemia. Five patients were complicated with sepsis before the second SCT. The median elapsed time from first CBT to the diagnosis of primary GF was 27 days. Secondary GF was diagnosed on day 567. The median elapsed time from primary GF to second SCT was 9 days. In the patient with secondary GF, the elapsed time was 35 days. Cord blood grafts were used in 5 patients and a matched sibling donor in one patient. All 6 patients underwent second transplantation following a modified '1-day'-based preparative regimen consisting of fludarabine (30 mg/m(2), 1 day, n = 2; 2 days, n = 1; 3 days, n = 3), cyclophosphamide (2 g/m(2)), and total body irradiation (2 Gy). All patients achieved neutrophil engraftment, and the median elapsed time from second SCT to engraftment was 35 days. Four patients remain alive between 5 and 38 months after second SCT. '1-day'-based short-term conditioning may be a promising salvage regimen.