Effect of recombinant erythropoietin and bone marrow aspiration findings in patients with chronic hemodialysis

Decreased production of erythropoietin is the major cause of anemia in chronic hemodialysis patients. It has been suggested, however, that many other factors influence this anemia. We administered recombinant erythropoietin (rEPO) to chronic hemodialysis patients, and studied its effects and the factors influencing those effects. Bone marrow findings were also examined. The subjects were 12 patients (6 males and 6 females). Anemia was remarkably improved by rEPO. However, the increase in hematocrit (Ht) value was favorable in some patients but not in others. In the former group, the ferritin level before administration was significantly higher than that of the latter group. The amount of blood transfusion during the six months prior to administration tended to be higher in the former group. There were no significant differences between the two groups in age, sex, duration of dialysis, dose of rEPO, Ht value, or other blood biochemical parameters before administration. Marrow tissues were aspirated by bone marrow puncture before and after medication from three patients. No significant changes were observed in M/E ratio, erythroblast classification, sideroblast ratio or state of iron granules in sideroblasts. These results indicate that rEPO is effective for anemia in hemodialysis patients. However, no definite pattern was found in the improvement of Ht value. It is thought, therefore, that certain factors influence the effect of rEPO. Since the ferritin level was significantly higher in patients showing favorable improvement of anemia than in those without such improvement, it is assumed that rEPO has a more favorable effect on erythropoiesis in patients who have a greater capacity to store iron in bone marrow. It was difficult to evaluate the effect of rEPO from findings of bone marrow alone. We consider the combined examination of erythroid progenitor cells to be required for proper evaluation.