Serum Ferritin: Deceptively Simple or Simply Deceptive? Lessons Learned From Iron Therapy in Patients With Chronic Kidney Disease

Abstract

Iron is an essential micronutrient that is indispensable for erythropoesis. Correct assessment of iron stores is needed both for the diagnosis of iron deficiency and to direct iron replacement therapies. Serum ferritin is a commonly employed measure to assess iron stores, yet there are caveats that influence its accuracy as a diagnostic tool. While low ferritin levels are specific for iron deficiency, high levels can be the result of inflammation, liver disease, or malignancies and could be independent of iron stores. Optimal anemia management involves administration of adequate amounts of iron. The right dose of iron that allows optimal erythropoesis yet avoids oxidative stress is a matter of ongoing debate, especially when using imperfect diagnostic tools such as serum ferritin to direct therapy. Data from hemodialysis patients are presented to illustrate the challenges one faces when trying to achieve the best possible therapeutic benefit from iron-replacement therapy.