Reduced-intensity conditioning regimens before unrelated cord blood transplantation in adults with acute leukaemia and other haematological malignancies.

Cord blood is an unlimited source of haematopoietic stem cells for allogeneic haematopoietic stem cell transplants. During the past 5 years, the number of adults transplanted with cord blood cells from unrelated donors has exceeded the number of transplants in children, as a result of better definitions of cord blood unit choice, an increased number of cord blood units available for transplantation worldwide, comparable results of unrelated cord blood transplantation (UCBT) with human leukocyte antigen-matched unrelated bone marrow transplantation, the use of double cord blood transplantation and the use of UCBT after a reduced-intensity conditioning (RIC) regimen. In spite of the encouraging results of RIC UCBT in single-centre studies, the number of patients given this strategy is still limited and follow-up is still too short to draw definitive conclusions. Moreover, many questions remain to be answered such as: (1) the type of patients and disease populations that may benefit most from this strategy; (2) the best conditioning regimen to use; (3) the criteria of cord blood choice in this setting; and (4) factors predictive of outcomes after RIC UCBT. This paper will summarize some recent results of RIC UCBT for adults with haematological malignancies.