Evaluating iron status in hemodialysis patients.

Iron is essential for hemoglobin formation and productive erythropoiesis. In hemodialysis patients, accurately assessing iron status is a prerequisite for diagnosing iron deficiency, monitoring the response to iron supplementation, and maintaining effective erythropoiesis. Ideal laboratory tests of iron status should accurately indicate whether a patient has an excess or deficiency in stored iron as well as in iron readily available for erythropoiesis. Serum ferritin and transferrin saturation (TSAT) are iron indices recommended by the K/DOQI guidelines for assessing iron deficiency and iron overload. However, since serum ferritin and TSAT are indirect measures of iron status, they can be unreliable in hemodialysis patients, particularly in those who are receiving recombinant erythropoietin. Relying on inaccurate indices of iron status can lead to false interpretations of iron overload or iron deficiency, which may lead to the unnecessary discontinuation or overdosing of iron supplementation. Newer methods of measuring iron status, such as reticulocyte hemoglobin content (CHr), may be less variable and more sensitive and specific than the current iron parameters.