Is erythropoietin a survival factor for red blood cells?

Recombinant human erythropoietin (rhuEPO) therapy has been reported to maintain corrected hematocrit values by increasing the length of red blood cell (RBC) survival. This article presents a controlled study that assessed the RBC survival before, during, and after termination of prolonged rhuEPO treatment of chronic hemodialysis patients. Two groups of 20 patients were studied. The hematocrit value of each patient was below 28 vol%. One group (Group A) was treated with rhuEPO for 1 yr and then treatment was stopped because of the unavailability of the drug. The second group (Group B) was treated for 2 yr. Epoetin beta was administered subcutaneously. The initial dose was 20 U per kg body weight three times weekly. Upon reaching the target hematocrit value of 30 to 35 vol%, the dose was individualized for each patient, to maintain target range. RBC survival was determined by the chromium-51 technique. In Group A, RBC survival was determined: (1) before, (2) at 12 months, and (3) 1 yr after cessation of rhuEPO treatment. In Group B, RBC survival was determined: (1) at 24 months of therapy, and (2) 1 yr after cessation of rhuEPO treatment. RBC survival increased significantly in both patient groups under rhuEPO treatment. After cessation of therapy, the RBC survival decreased to pretreatment values. During the correction period, reticulocyte counts increased significantly in both groups. Over the maintenance period, they slightly decreased, and after termination of rhuEPO therapy, they decreased to the pretreatment values. The results of this study could suggest the possibility that RBC survival was prolonged by the action of EPO on the erythroid progenitors, resulting in the production of RBC with improved viability.