Switching of donor cells after urgent second cord blood transplantation for suspected graft failure

Cord blood transplantation (CBT) is being increasingly performed in adults and is now becoming a standard therapeutic alternative to bone marrow transplantation; however, graft failure is one of the associated problems of CBT in adults. A 44-year-old woman with acute myelogenous leukemia in partial remission received an unrelated CBT. Suspected veno-occlusive disease developed, however, and hemopoietic recovery was delayed. A bone marrow examination on the 27th day revealed empty marrow with a relative increase in macrophages, and the serum ferritin concentration was extremely high. Impending failure of the graft due to a hemophagocytic syndrome-like condition was strongly suspected, although donor cells were dominant according to a fluorescence in situ hybridization analysis. A second CBT was performed on the 30th day after a preparatory regimen of methylprednisolone and low-dose fludarabine (total dose, 90 mg/m2). Unexpectedly, the the first donor's cells recovered on the fourth day after the second CBT; however, the cells to finally engraft were those of the second donor. This case is informative as an example of rescue management for suspected graft failure.