Haematopoietic stem cell transplantation: current concepts and novel therapeutic strategies.

INTRODUCTION: Haematopoietic stem cell transplantation (HSCT) is potentially curative for haematological diseases. New developments are improving its applicability and success. Sources of data A literature search was conducted on peripheral blood haematopoietic stem cell (PBHSC) mobilization, umbilical cord blood (UCB) transplantation, reduced intensity conditioning (RIC) and acute graft-versus-host disease (aGVHD). AREAS OF AGREEMENT: PBHSC mobilization by granulocyte colony-stimulating factor and chemomobilization may fail in up to 30% of patients previously treated with extensive chemotherapy. New mobilization agents, notably the CXCR4 antagonist, have improved mobilization efficacy. UCB-HSCT is equally feasible in children and adults. RIC enables HSCT to be performed in patients who are elderly or with serious medical co-morbidities. RIC-HSCT is associated with increased frequency of graft failure and disease relapse. The prophylaxis and treatment of aGVHD are still problematic. AREAS OF CONTROVERSY: Novel strategies in PBHSC mobilization, utilization of UCB-HSCT and RIC-HSCT and prophylaxis and treatment of aGVHD, have not been critically appraised or compared with conventional strategies. AREAS TIMELY FOR DEVELOPING RESEARCH: The safety and efficacy of novel mobilization agents have to be tested in normal allogeneic donors. Methods of increasing the cell dose or efficacy of UCB should be developed, to extend its use to adults. RIC-HSCT should be compared with conventional HSCT in young patients. Continuous efforts in defining the best prophylaxis and treatment of aGVHD should be made.