Validation of serum ferritin values by magnetic susceptometry in predicting iron overload in dialysis patients.

Background: Guidelines for treating anemia in dialysis patients accept, as high-end range of serum ferritin useful to optimize erythropoietin therapy, values high as 500 to 900 microg/L, on the hypothesis that ferritin might be not representative of iron overload.

Methods: A superconducting quantum interference device (SQUID) was used to make direct noninvasive magnetic measurements of nonheme hepatic iron content in 40 dialysis patients treated with intravenous iron, and liver iron content was compared with biochemical markers of iron status.

Results: Only 12/40 (30%) patients showed normal hepatic iron content (SQUID <400 microg/g), while 32.