Improvement of anemia by recombinant erythropoietin in patients with myelodysplastic syndromes and aplastic anemia.

Eight patients with myelodysplastic syndromes (MDS) and four patients with aplastic anemia (AA) were treated with recombinant erythropoietin (rEpo) to investigate its effect on the anemia of these patients. rEpo was administered by i.v. injection three times a week for at least four weeks. The doses were 3,000, 6,000, or 12,000 U/day. Despite an elevated "endogenous" Epo level, a greater than 1.5 g/dl increase in hemoglobin (Hb) concentration was observed in one patient with refractory anemia (RA), one patient with refractory anemia with excess of blasts (RAEB), and one patient with AA. A greater than 50% decrease in red cell transfusion requirement was observed in one patient with RA and one patient with AA. One RA patient and one AA patient have received rEpo as maintenance therapy for more than 64 and 100 weeks, respectively. They no longer need red cell transfusions and have had a normal Hb concentration and normal ferrokinetics. No side effect was seen. These results indicate that rEpo may benefit some patients with MDS and AA who are dependent on red cell transfusions while further studies will be necessary to elucidate the mechanism by which rEpo stimulates erythropoiesis and improves anemia in patients with these diseases.