[Erythropoietin--the first hematologic hormone in clinical use]

Recombinant human erythropoietin raises serum erythropoietin concentrations to adequate levels and restores the hematocrit to normal values in the vast majority of anemic, end stage renal disease patients undergoing regular hemodialysis. It can eliminate the need for transfusions and thus the risk of immunologic sensitization, infection and iron overload. Erythropoietin not only alters laboratory findings but improves the well being and performance of patients on hemodialysis as well. Side effects are minimal and neither antibodies nor resistance to the recombinant hormone have been observed so far. Along with the rise in hematocrit and blood viscosity some patients developed increased blood pressure and a few hypertensive encephalopathy, but after brief interruption of therapy erythropoietin treatment could be continued in combination with antihypertensive drugs. The pathophysiology of the increase in blood pressure, the risk of encephalopathy and the possibly somewhat higher risk of thrombosis remain to be elucidated. Nevertheless, the first recombinant hematopoietic hormone has passed its first clinical trials with success.