Short-term small-dose intravenous iron trial to detect functional iron deficiency in dialysis patients

BACKGROUND/AIM: Management of renal anemia in end-stage renal disease requires careful evaluation of the iron status before and in particular during erythropoietin treatment. However, there is no simple and practical iron index accurately predictive of functional iron deficiency in these patients till now. The purpose of this prospective study, therefore, is to evaluate whether a short course of low-dose intravenous iron challenge can detect functional iron deficiency in hemodialysis patients. METHODS: Twenty-four patients with baseline serum ferritin levels between 100 and 500 ng/ml were treated with intravenous saccharated ferric oxide, 960 mg over 24 hemodialysis treatments, and the hemoglobin level was checked every week. RESULTS: Patients whose hemoglobin value increased at least by 1 g/dl within the 8-week period were classified as having functional iron deficiency or as responders (n = 26; 81.2%). All other subjects were classified as having adequate iron levels or as nonresponders (n = 6; 18.8%). There were no significant differences in age, sex, dialysis years, Kt/V, dialyzers, hemoglobin, and basal and final transferrin saturation and ferritin between responders and nonresponders. In addition, there were no iron indices with acceptable levels of sensitivity and specificity. On the contrary, the cutoff value of increments of hemoglobin of at least 0.2 g/dl after a 2-week intravenous iron trial had a sensitivity of 96.2% and a specificity of 100% in all patients (n = 32) and a sensitivity of 100% and a specificity of 100% after patients with transferrin saturation <20% were excluded (n = 24). These values had the greatest utility of the tests studied in this work. CONCLUSION: A 240-mg intravenous iron challenge during a 2-week period may be a simple, accurate, and straightforward method to detect a functional iron deficiency status in hemodialysis patients undergoing erythropoietin therapy.