Intravenous iron, inflammation, and oxidative stress: is iron a friend or an enemy of uremic patients?

Intravenous iron supplementation is a recognized therapy for anemia in chronic hemodialysis patients, especially in those treated with erythropoietin. The vast majority of patients with chronic kidney disease (CKD) seem to be iron-deficient, as evaluated by the usual parameters and by iron staining on bone marrow biopsy, because of multiple forms of interference with all phases of iron metabolism. The need for iron supplementation in CKD patients becomes obvious. Intravenous iron was demonstrated to be superior to oral iron in hemodialysis patients. There is also evidence for the superiority of intravenous iron in peritoneal dialysis and in nondialysis-dependent CKD patients. On the other hand, intravenous iron could promote cytotoxicity and tissue injury, and exacerbate oxidative stress and thus endothelial dysfunction, as well as inflammation and the progression of both CKD and cardiovascular disease. Nevertheless, correction of anemia is effective in reducing oxidative stress and, consequently, cardiovascular risk. The overall risk-benefit ratio favors the use of intravenous iron alone or with an erythropoietic stimulating agent in the management of renal anemia. Clinical judgment is necessary in each individual case to diagnose iron deficiency and effectively use intravenous iron.