[In vitro production of red blood cells for future transfusion medicine].

Large-scale in vitro red blood cell (RBC) production has been attempted in recent years. Potential cell sources for RBC production include hematopoietic stem/progenitor cells, pluripotent stem cells, and immortalized erythroid progenitor cell lines, which can induce enucleated RBCs with characteristics such as oxygen-carrying capacity and deformability. A phase I clinical study of cultured RBCs produced from hematopoietic stem/progenitor cells has revealed a similar in vivo half-life between cultured and native RBCs. Thus, the application of cultured RBCs in blood transfusion is gradually advancing. However, a single transfusion requires a large number of cells, unlike other cell therapies. Therefore, developing a method to mass-produce RBCs from a small culture volume at a low cost is important in the future. This review summarizes the current status and prospects concerning in vitro RBC production using each cell source, which can improve future transfusion medicine.