ERYTHROPOIESIS IN PATIENTS STIMULATED WITH ERYTHROPOIETIN - THE RELEVANCE OF STORAGE IRON

Background and Objectives: The clinical importance of iron-restricted erythropoiesis in erythropoietin (EPO)-stimulated patients is controve rsial, Materials and Methods: We therefore reviewed 70 patients random ized into clinical trials of aggressive autologous donation and oral i ron supplementation, with or without recombinant human EPO therapy. Re sults: Nineteen (27%) iron-depleted patients produced 5.4 +/- 2.8 ml R BC/kg compared to 4.8 +/- 2.3 ml RBC/kg (nonsignificant) in iron-reple te patients due to endogenous EPO (placebo group) stimulation. EPO-tre ated iron-depleted patients produced 20% less RBC than iron-replete pa tients (8.23 +/- 3.3 vs. 10.2 +/- 4.0, p = 0.066), RBC volume expansio n correlated with initial storage iron only in iron-replete patients w ho received EPO therapy, Conclusion: Initial storage iron status is a marginally important limitation to EPO-mediated erythropoiesis in the setting of oral iron supplementation. Strategies to maintain plasma tr ansferrin saturation with intravenous iron therapy may be desirable to improve the erythropoietic response to EPO in this setting.