title: Stem cell-derived erythrocytes as upcoming players in blood transfusion.
abstract: BACKGROUND
  Blood transfusion is current standard-of-care for genetic forms of anemia that would be otherwise lethal and allows implementation of aggressive cytotoxic/surgical therapies developed for numerous types of cancer. In developed countries the blood supply is adequate and sporadically even in excess. However, difficulties exist in finding blood with rare phenotypes to treat alloimmunized patients and the progressive ageing of the human population predicts that blood will become scarce by 2050. These considerations establish the need for the development of techniques to generate cultured red blood cell (cRBCs) as transfusion products.
  
  
  METHODS
  Recent progress in cell culture techniques is revolutionizing organ replacement therapies. Two new disciplines, cell therapy and tissue engineering, have been developed to generatein vitrotherapeutic products for a variety of applications ranging from skin grafts to organ-function repairs. It is currently believed that these advances will eventually allowex-vivoproduction of various cell types in numbers so great that, in the case of red cells, would be clinically adequate for transfusion.
  
  
  RESULTS
  Proof-of-principle in animal models indicate that cRBCs generated from murine embryonic stem cells protect mice from lethal anemia. Conditions to generate small amounts of clinical grade cRBCs have been established and the first-in-man administration of autologous cRBCs perfomed. The results of this trial indicate that cRBCs survivein vivoat least as long as their natural counterpart.
  
  
  CONCLUSIONS
  These ground-breaking reports have raised great excitement for clinical evaluation ofcRBCsfor transfusion. However, skepticism still persist that production of cRBCs in numbers sufficient for transfusion will ever be possible. This paper will discuss diagnostic and clinical goals pursuable with numbers of cRBCs that may be generated with current technology.
  
  
  CONCLUSIONS
  We are confident that development of relevant clinical goals achievable with current technologies will not only improve clinical care in transfusion medicine but will also foster studies to overcome scientific and technical barriers that render transfusion with cRBCs of the general population impractical today.
authors.affiliation: Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore Sanità, Rome, Italy ; Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Migliaccio
keywords: adult haematopoietic stem cells; anaemia; cord blood; embryonic stem cells; erythropoiesis; induced pluripotent stem cells