Review and outlook on unrelated cord blood transplantation for treatment of malignant hematological diseases in adults

Abstract

There are currently more and more unrelated cord blood transplants (UCBT) performed in adults patients with hematological malignancy. Umbilical cord blood is an important hematopoietic progenitor cell source for patients. Recent studies showed comparable curative effect among patients of acute leukemia receiving UCBT, haplo-identical hematopoietic stem cell transplantation, unrelated bone marrow transplantation and peripheral blood stem cell transplantation. The advantage of single UCBT has low incidence rate of graft versus host disease (GVHD) and is easy to control. Also, single UCBT maintains better graft versus tumor (GVT) effects and better quality of life. However, the disadvantage of UCBT is that the number of umbilical cord blood is so low and that the engraftment of UCBT is slow, especially in UCBT for adults. The immune reconstitution after UCBT is also slow, and results in early infection after transplantation. Improve engraftment and reconstitute immune system can significantly improve clinical outcomes. In this review, we further advance the usage of UCBT in adult patients with malignant hematological disease, and prospect the methods to enhance hematopoietic stem cell expansion, improve engraftment, reconstitute immune system and select the best human leukocyte antigen (HLA) matching. Key words: Umbilical cord blood transplantation; Malignant hematological disease; Graft vs host disease; Graft versus tumor effect; Cord blood bank