Quick Review Cards for Medical Laboratory Science

Iron and Related Tests Clinical Chemistry Review 97

ANALYTE REFERENCE RANGE CLINICAL SIGNIFICANCE OTHER

Iron

Total iron binding
capacity (TIBC)

% saturation or
transferrin saturation

Transferrin

Ferritin

M: 65–175

F: 50–170 μg/dL

250–425 μg/dL

20%–50%

200–360 mg/dL

M: 20–250

F: 10–120 μg/L

↑iron overdose, hemochromatosis,

sideroblastic anemia, hemolytic

anemia, liver disease

↓iron deficiency anemia

↑iron deficiency anemia

↓iron overdose, hemochromatosis

↑iron overdose, hemochromatosis,

sideroblastic anemia

↓iron deficiency anemia

↑iron deficiency anemia

↓iron overdose, hemochromatosis,

chronic infections, malignancies

↑iron overload, hemochromatosis,

chronic infections, malignancies

↓iron deficiency anemia

Necessary for hgb synthesis. Transported

by transferrin. Hemolysis interferes.

Oxalate, citrate, & EDTA bind iron. Early-

morning specimen preferred because of

diurnal variation. Colorimetric methods.

Iron added to saturate transferrin.

Excess removed. Iron content

determined.

Calculated value. 100× serum iron/TIBC.

Complex of apotransferrin (protein that

transports iron) & iron. Immunoassay.

Storage form of iron. Rough estimate of

body iron content. Immunoassay.