Peripheral blood stem cell transplantation

High dose chemo/radiotherapy requiring autologous haemopoietic stem cell support is increasingly used in a variety of malignant disorders. Mobilised peripheral blood stem cells (PBSC) have largely replaced the use of autologous bone marrow due to more rapid haemopoietic reconstitution with less resource use including blood and platelet transfusion requirements. PBSC graft adequacy is monitored by CD34+ cell and granulocyte-monocyte-colony-forming-cell measurements, and thresholds for rapid engraftment have been determined. Studies are in progress to determine the optimal mobilisation regimens that will permit the achievement of the necessary progenitor thresholds with only one or two aphereses. This will facilitate the use of multiple cycles of high dose therapy and possibly the use of PBSC collected by venesection rather than apheresis. PBSC are also increasingly used in the allogeneic setting where specific mobilisation protocols not using cytotoxic drugs are employed. These technical advances will aid the execution of large trials to determine the efficacy of high dose therapy.