[Erythropoietin, a milestone in the history of nephrology].

Erythropoietin, a glycoprotein, is synthesized mainly in the kidney. With the destruction of renal tissue, erythropoietin production decreases; this is a major factor in the development of anemia in patients with renal failure. For about ten years now, recombinant human erythropoietin has been available for the treatment of renal anemia. All patients with renal insufficiency, independent of their plan for future renal replacement therapy, may benefit from erythropoietin. At what extent of anemia erythropoietin therapy should be started is still discussed and is certainly dependent on the degree of the patient's impairment by his anemia. Before beginning a therapy with erythropoietin, other forms of anemia observed in patients with renal failure, i.e. mainly iron deficiency, have to be excluded. A strict monitoring of hematocrit during treatment with erythropoietin is mandatory. Hypertension, seizures and cardiovascular complications have been observed with overdosing of erythropoietin. Special emphasis of this review is therefore put on the discussion of the dynamics of the erythropoietin-red cell system.