Iron infusion and deposition in the kidney.

BACKGROUND: Parenteral iron therapy is the mainstay of treating iron deficiency anemia in chronic kidney disease (CKD) patients.
METHODS: Retrospective case study of iron staining of renal tissues in 2 CKD patients who had received intravenous iron prior to the renal biopsy.
RESULTS: Following the infusion of ferumoxytol, iron staining of renal biopsy demonstrated blue curvilinear deposition of iron in the tissue macrophages (histocytes) and interstitium of the kidney. Renal iron deposition was not observed in a patient administered intravenous iron dextran.
CONCLUSION: We postulate that the higher molecular weight of ferumoxytol and different carbohydrate components may lead to deposition and trapping of the ironcarbohydrate complexes in the reticuloendothelial system of the kidney. Potential renal toxicity from iron induced oxidant stress, especially in patients with underlying chronic kidney disease, merits further investigation.