Iron, Total and Total Iron Binding Capacity (Iron TIBC)

Serum iron quantification is useful in confirming the diagnosis of iron-deficiency anemia or hemochromatosis. The measurement of total iron binding in the same specimen may facilitate the clinician’s ability to distinguish between low serum iron levels caused by iron deficiency from those related to inflammatory neoplastic disorders. The assay for iron measures the amount of iron which is bound to transferrin. The total iron binding capacity (TIBC) measures the amount of iron that would appear in blood if all the transferrin were saturated with iron. It is an indirect measurement of transferrin concentrations but expressed as an iron measurement. To obtain the percent saturation, the serum iron is divided by the TIBC which gives the actual amount of saturated transferrin. The percent saturation is low in iron deficiency and high in iron storage diseases.