Although peripheral blood stem cell (PBSC) transplantations in an unrelated transplant setting have been performed since 2010, prior harvesting and cryopreservation of PBSCs from unrelated donors has not been approved in Japan. There are no restrictions with regard to related donors. Therefore, in April 2015, we conducted a nationwide survey and obtained written answers from 123 transplant hospitals throughout Japan. Our survey revealed that as much as 81.3% of transplant hospitals routinely perform prior harvesting and cryopreservation of PBSCs from related donors and that both cell processing and quality management of cryopreserved products have been appropriately conducted in line with domestic guidelines, although post-thaw quality control and storage period setting require further improvements. Moreover, informed consent obtained from both patients and donors with regard to cryopreservation of PBSCs was not always sufficient in some hospitals. We found that the average number of unused or discarded cryopreserved PBSCs is 1.09 per hospital, and the overall nonuse or discard rates of cryopreserved PBSCs were estimated to be as low as 2.67%.
Keywords: Cryopreservation; Peripheral blood stem cell; Prior harvesting; Related donors.