Strategies to enhance graft performance in cord blood transplantation

Abstract

Umbilical cord blood (CB) serves as one of the alternative donor sources for hematopoietic stem cell transplantation (HSCT) in those patients lacking a matched related donor. However, the relatively high incidence of engraftment failure and/or delayed engraftment following cord blood transplantation (CBT) has been a major obstacle against its success. The usage of two CB units has made CBT possible in adults when a single CB unit with an adequate cell number is lacking, but it failed to demonstrate any beneficial effect in children and adolescents. In recent years, unmanipulated haploidentical graft has been replacing CB owing to its rapid availability along with low incidence of acute and chronic graft-versus-host disease due to the usage of post-transplant cyclophosphamide. Given this situation, overcoming the engraftment related issues is crucial in order for CBT to remain a realistic alternative of allogeneic HSCT. This review discusses the engraftment-related issues in CBT and recent advances to overcome those, highlighting the role of conditioning, ex vivo CB stem cell expansion, and cotransplantation of mesenchymal stem/stromal cells.

Keywords

• conditioning
• cord blood transplantation
• engraftment
• ex vivo expansion
• mesenchymal stem cells