Resistance to recombinant erythropoietin (rEPO) in hemodialysis patients may be due to inadequate iron recruitment and defect in iron use. In this cross over randomized clinical trial, 30 hemodialysis patients with serum ferritin levels of ≥500 ng/ml, hemoglobin ≤11.0 g/dl, and transferrin saturation (TSAT) of 20% or less were administrated intravenous iron (50-100 mg/wk) and rEPO (120-360 U/kg/wk) for 6 months. Patients were excluded if there was a clear explanation for rEPO hyporesponsiveness. Patients were divided into two groups. Group1 received standard care and 500 mg of intravenous ascorbic acid (IVAA) with each dialysis session in the first week of each month for a total of 3 months. Group 2 received standard care only. After 2 month washout period, groups were crossed over. Each month hemoglobin (Hb) was assessed. Iron, TIBC (transferrin iron binding capacity), TSAT, iPTH (intact parathyroid hormone), liver enzymes, albumin and cholesterol levels were measured every 3 months. After 3 months of intervention, Hb significantly increased from 10.11 to 12.19 g/dl (P <0 0.001; 95% confidence interval [CI] 2.7-1.4) and TSAT increased from 18.9 to 28.1% (P = 0.008; 95% CI 0.09-3), while ferritin and serum iron declined significantly from 1391 to 938 ng/ml (P = 0.001; 95% CI 216-689), 97.2 to 64.6 (P = 0.001; 95% CI 14.8-50.4) in the study group. Change of Hb over time in IVAA group was significant (P < 0.0005). There were significant differences between two groups in change of Hb level over time (P < 0.0005) and treatment effect (P = 0.002). Baseline laboratory tests were similar in the two groups and there was no carry over effect at phase 2. We showed that low amount of IVAA could reduce ferritin level and enhance Hb and TSAT, suggesting improved iron utilization.
Keywords: Anemia; ascorbic acid; hemodialysis.