Prospects for the manufacture of red cells for transfusion.

Whilst red cell transfusion is a well established cellular therapy, the problems of insufficiency of supply, transfusion transmitted infections and the requirement for immunological matching persist. The possibility of generating large numbers of O Rh D negative red cells at Good Manufacturing Practice grade as a route to circumvent these issues is therefore an attractive proposition. Significant numbers of erythrocytes can be generated from somatic haematopoietic stem cells, but it seems unlikely that these can provide sufficient volumes for large scale manufacture. However, human embryonic stem cells (hESC) and, potentially, induced pluripotent stem cells (iPSC), may provide a route to this objective. Red cell transfusion is an attractive goal for pluripotent stem cell-derived therapeutics because it is a well-characterised single cell suspension that lacks nucleated cells and has a low expression of human leucocyte antigen molecules, but many challenges remain in translating this cellular therapy to the clinic.