Reduction in erythropoietin doses by the use of chronic intravenous iron supplementation in iron-replete hemodialysis patients

Background: Iron deficiency is the most common cause of suboptimal response to recombinant human erythropoietin (rHuEPO) in chronic hemodialysis (HD) patients. Iron supply can correct this situation, however, optimal dosage, route of administration, and monitoring of iron status during rHuEPO therapy in maintenance HD patients remains controversial. Methods: We conducted a 12-month intravenous iron substitution trial in 149 iron-replete chronic HD patients receiving subcutaneous rHuEPO therapy. The available iron pool was maintained with 100 mg iron every 2 weeks or 1 month depending on serum ferritin and transferrin saturation levels, the rHuEPO dosage titrated depending on hematocrit (Hct) levels. Results: After 12-month protocol, the Hct increased (28.7+/-4.1 vs 27.7+/-2.6, p=0.003), rHuEPO requirement reduced 25% (46.1+/-28.9 vs 61.5+/-67.8 U/kg/week, p=0.006), serum ferritin increased (1383+/-727 vs 930+/-857 ng/ml, p<0.001), so did the transferrin saturation (36.1 +/- 12.7 vs 27.5 +/- 12.8%, p<0.001). The serum albumin decreased slightly but reached statistical significance (4.1+/-0.48 vs 4.2+/-0.36 g/dl, p=0.006), so did the cholesterol levels (166+/-41 vs 173+/-38 mg/dl, p=0.044) and pre-dialysis creatinine (11.3+/-2.3 vs 11.5+/-2.4 mg/dl, p=0.015). Besides, the iPTH levels did not interfere with the rHuEPO dosage reduction and Hct increment in our patients. Conclusion: We conclude that maintaining high levels of serum ferritin and transferrin saturation could further reduce the requirement of rHuEPO in chronic HD patients, but the long-term effect of iron overloading to patients' nutritional status must be further evaluated in contrast to the economic saving.