Milestones in umbilical cord blood transplantation.

Since the first human cord blood transplant, performed in 1988, cord blood banks have been established worldwide for collection and cryopreservation of cord blood for allogeneic hematopoietic stem cell transplant. Umbilical cord blood (UCB) has now become one of the most commonly used source of hematopoietic stem cells for allogeneic transplantation. Today a global network of cord blood banks and transplant centers has been established for a common inventory with an estimated 600,000 UCB have been banked and more than 20,000 UCB units distributed worldwide for adults and children with severe hematological diseases. Several studies have shown that the number of cells is the most important factor for engraftment while some degree of HLA mismatches is acceptable. The absence of ethical concern, and the unlimited supply of cells explain the increasing interest of using cord blood for developing regenerative medicine.