抄録
Umbilical cord blood is being increasingly used as an alternative source of hematopoietic stem cells for allogeneic bone marrow transplantation. However, a major problem with cord blood transplantation is that it is associated with slow platelet engraftment compared to stem cell transplantation using bone marrow or cytokine-mobilized peripheral blood. Several studies have suggested that the slow platelet engraftment is due to low absolute numbers of megakaryocyte progenitor cells in umbilical cord blood. We examined whether the number or quality of infused colony-forming units megakaryocyte (CFU-Mk) were related to the speed of platelet recovery of 21 patients who received cord blood transplantation with marrow-ablative chemotherapy. The proportion of small Mk colonies per unit was inversely correlated with the time to platelet recovery (p=0.034, r=-0.67), whereas no such correlation was seen with the number of infused CFU-Mk per kg. These results indicate that the proportion of mature megakaryocyte progenitor cells per unit reflects the hematopoietic potential of a cord blood graft, and may correlate with the speed of platelet recovery after transplantation.
