The use of recombinant human erythropoietin in hemoglobinopathy and uremia

Response to recombinant human erythropoietin (rhEPO) is varied. Some patien ts will have excellent hematocrit values on small to moderate doses, while others may be significantly hyporesponsive. A need for > 300 IU/kg/wk of rh EPO defines an inadequate response. The most common cause of inadequate res ponse to rhEPO therapy is absolute or functional iron deficiency; but alumi num overload, infection and sepsis, chronic disease and inflammation, hyper parathyroidism, inadequate dialysis, and drug interactions can also cause r hEPO resistance. In dialysis patients, hemoglobinopathy is another very imp ortant factor with regard to rhEPO hyporesponsiveness. On the basis of avai lable evidence, in thalassemia minor there is the necessity to employ highe r rhEPO doses than in uremic controls-doses greater than the 300 IU/kg/wk c ited as the definition of rhEPO hyporesponsiveness by much of the world's c linical practice guidelines. In end-stage renal disease patients with sickl e cell disease, however, the hemoglobin should not be increased above 6-9 g /dl in order to avoid painful crises.