Abstrait

Transplantation of cord blood stem cells for treating hematologic diseases and strategies to improve engraftment

Philippe Taupin

Umbilical cord blood (CB) offers an alternative source of hematopoietic stem cells for the treatment of malignant and nonmalignant hematologic diseases. Umbilical CB has high levels of repopulating hematopoietic stem cells and is depleted of immune cells. It elicits low cell dose, and delayed and poor engraftment to the bone marrow. Umbilical CB is used for pediatric transplants as well as in adults. CB transplantation is associated with a high rate of mortality and morbidity, particularly in adults. To improve the success rate, patients are treated with a double CB dose. However, such a strategy limits the availability of CB transplants for patients and the conditions are still suboptimal. Novel avenues are being devised and considered; among them the expansion and propagation of CB stem cells in vitro, and the improvement of homing and engraftment of CB stem cells to the bone marrow. Such strategies would overcome the low cell dose in CB units by improving the delay and engraftment of CB stem cells to the bone marrow. Therefore, it would reduce the risk of early infections, improve the success rate of CB transplantation and make CB transplantation available to more patients. Umbilical CB offers a promising model for cellular therapy and regenerative medicine.