Erythropoietin: mechanisms of action and indications for treatment

We review data concerning site and regulation of erythropoietin (EPO) production, its effects on target tissue, routes of administration and clinical applications. In the anaemia of chronic renal failure (ACRF) treatment with recombinant human erythropoietin (r-Hu-EPO) has been shown to be effective in both improvement of the anaemia and increase in quality of life. In the anaemia of chronic disease (ACD), associated with various malignant, infectious and inflammatory disorders, many investigators have demonstrated an inappropriately low EPO response to anaemia. Therapeutic trials in patients with ACD mostly lacked sufficient numbers of patients for evaluation of the effects. The results obtained from some studies in AIDS and rheumatoid arthritis and the effect on the number of units of autologous blood obtained from patients planned for elective surgery are encouraging, however. Adverse reactions of r-Hu-EPO treatment are mainly confined to the ACRF population and include hypertension, shunt thrombosis and pain at the injection site. The exact mechanism of action of EPO is not yet fully understood. Large scale clinical trials are required to establish its effects on both the anaemia and quality of life in anaemias other than ACRF.