REVIEW ARTICLE THE ROLE OF RECOMBINANT GROWTH FACTORS IN TRANSFUSION MEDICINE

There is renewed interest in alternatives to blood transfusion. The changing environment of trans-fusion medicine includes increased awareness of patients and physicians as to the problems of safety of blood, desirability of blood conservation, and in-formed consent before elective blood transfusion [29]. For example, physicians may be more con-servative in respect of the PCV at which transfusion is indicated [14] in anaemic medical and surgical patients [56]. This includes orthopaedic surgery patients who choose to predeposit autologous blood [55]. Similarly, the use of blood and blood com-ponents has been reduced substantially by the use of strategies for blood conservation during surgery. A combination of techniques such as preoperative autologous blood donation, acute haemodilution, use of non-blood pump prime, intra- and postoperative autologous blood salvage and reinfusion and, most importantly, acceptance of normovolaemic anaemia after operation, have resulted in a reduction in red blood cell transfusion in the United States [52]. In addition to these methods of blood conser-vation, recombinant growth factors now show prom-ise in reducing or eliminating the requirement for homologous blood components, when used in com-bination with other blood conservation methods in a variety of clinical circumstances. This review con-siders recent developments in this area, including the haematopoietic growth factor recombinant human erythropoietin (rHuEPO), and the myeloid growth factors granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimu-lating factor (GM-CSF). STIMULATION OF HAEMATOPOIESIS: ERYTHROPOIETIN The development of rHuEPO, from identification as the hormone regulating erythropoiesis [7], to purifi-cation and identification [41] of human urinary erythropoietin, and subsequent cloning, expression and characterization as a recombinant product [6, 36, 53], has occurred in the relatively brief period of only 32 years (1953-1985). Furthermore, the ex-tension of this advance to direct use in the clinical treatment of anaemias has occurred within the very short interval of only 2 years