Intravenous ascorbic acid in hemodialysis patients with functional iron deficiency: a clinical trial

Background. Hemodialysis (HD) patients with functional iron deficiency (FID ) often develop resistance to recombinant human erythropoietin (rHuEpo). In these patients, iron therapy may be a hazard, leading to iron overload and consequently to hemosiderosis. Recent studies suggest that intravenous asc orbic acid (IVAA) may circumvent rHuEpo resistance. The aim of our study wa s to show the effects of IVAA on FID and whether this results in a better c orrection of anemia in HD patients with stable hemoglobin (Hb) concentratio n and FID. Methods. Twenty-seven HD patients with serum fenitin > 300 mug/I, transferr in saturation (TS) < 20 % and hemoglobin (Hb) < 10 g/dL were selected and r andomly divided into two groups to enter a cross-over trial with IVAA. In g roup I IV vitamin C 500 mg was administered three times a week for three mo nths and discontinued in the next three months of the study. Vitamin C was not given the first three months in group II. (control group, first three m onths of the study), who then received 500 mg TV three times a week for the next three months. Results. Hb and TS% significantly increased (baselines vs 3 months, Hb 9.2 +/- 0.2 vs 10.0 +/- 0.3 g/dL, TS% 17.5 +/- 0.6 vs 25.7 +/- 1.7, respectivel y p < 0.01 and p < 0.001) in group I after three months; ferritin fell sign ificantly from 572 +/- 40 to 398 +/- 55 mug/L (p < 0.004). Ten patients com pleted the study: mean Hb and TS% feb significantly (3 months vs final, Hb 9.9 +/- 0.3 vs 8.9 +/- 0.2 g/dL, TS% 25.1 +/- 1.2 vs 19.1 +/- 1.1, respecti vely p < 0.01 and p < 0.001), while mean ferritin did not change. Mean Hb, ferritin and TS% remained unchanged in group II after three months. Hb and TS% mean values rose significantly (3 months vs final, Hb 9.0 +/- 0.2 vs 9. 9 +/- 0.2 g/dl, TS% 18.4 +/- 1.0 vs 27.0 +/- 1.0, respectively p < 0.005 an d p < 0.001), and ferritin markedly decreased from 450 +/- 50 to 206 +/- 24 <mu>g/L (p < 0.001) at the end of the study. The rHuEpo dose was kept unch anged throughout the study. Differences were analyzed after three months. M ean Hb rose (0.8 +/- 0.2 g/dL) in group I but dropped (- 0.1 +/- 0.1 g/dL) (p < 0.009) in group II. Ferritin dropped in both groups (group I vs group II, - 173 +/- 48 vs - 33 +/- 21 mug/L) (p < 0.01) while TS% increased (grou p I vs group II, 8.2 +/- 1.5 vs 0.4 +/- 0.7) (p < 0.001). Conclusion. IVAA may partially correct FID and consequently help rHuEpo hyp oresponsive anemia.