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Test Catalog

Test ID: FERR    
Ferritin, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of iron deficiency and iron overload conditions

 

Differentiating iron deficiency anemia and anemia of chronic disease

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

See Hereditary Hemochromatosis Algorithm in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Ferritin is a large spherical protein consisting of 24 noncovalently linked subunits with a molecular weight of approximately 450,000 D. The subunits form a shell surrounding a central core containing variable amounts of ferric hydroxyphosphate. One molecule of ferritin is capable of binding between 4000 and 5000 atoms of iron, making ferritin the major iron storage protein for the body.

 

Ferritin is found chiefly in the cytoplasm of cells of the reticuloendothelial system and is a constituent of normal human serum. The concentration of ferritin is directly proportional to the total iron stores in the body, resulting in serum ferritin concentrations becoming a common diagnostic tool in the evaluation of iron status.

 

In most normal adults, serum ferritin concentrations vary with age and sex. There is a sharp rise in serum ferritin concentrations in the first month of life, coinciding with the depression of bone marrow erythropoiesis. Within 2 or 3 months, erythropoiesis becomes reactivated and there is a drop in the concentration of serum ferritin. By 6 months, the concentration is reduced to fairly low levels where they remain throughout childhood. There is no sex difference until the onset of puberty, at which time ferritin concentrations rise, particularly in males. There is a significant positive correlation between age and serum ferritin concentrations in females, but not in males.

 

Patients with iron deficiency anemia have serum ferritin concentration approximately one-tenth of normal subjects, while patients with iron overload (hemochromatosis, hemosiderosis) have serum ferritin concentrations much higher than normal. Studies also suggest that serum ferritin provides a sensitive means of detecting iron deficiency at an early stage. Serum ferritin concentrations may serve as a tool to monitor the effects of iron therapy, but results should be interpreted with caution, as these cases may not always reflect the true state of iron stores. Ferritin is a positive acute phase reactant in both adults and children, whereby chronic inflammation results in a disproportionate increase in ferritin in relation to iron reserves. Elevated ferritin is also observed in acute and chronic liver disease, chronic renal failure, and in some types of neoplastic disease.

 

Evaluating body iron stores may include serum iron determination, total iron binding capacity (TIBC), and percent saturation of transferrin, however are subject to diurnal variations and may be less precise. Additionally, they do not discriminate between depleted iron stores (iron deficiency) and conditions associated with defective iron release (eg, anemia of chronic disease).

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Males: 24-336 mcg/L

Females: 11-307 mcg/L

Interpretation Provides information to assist in interpretation of the test results

Hypoferritinemia is associated with increased risk for developing iron deficiency where iron deficiency is sufficient to reduce erythropoiesis causing hemoglobin concentrations to fall. Latent iron deficiency occurs when serum ferritin is low without low hemoglobin.

 

Hyperferritinemia is associated with iron overload conditions including hereditary hemochromatosis where concentrations may exceed 1000 mcg/L. Non-iron overload hyperferritinemia may be caused by common liver disorders, neoplasms, acute or chronic inflammation, and hereditary hyperferritinemia-cataract syndrome.

 

For more information about hereditary hemochromatosis testing, see Hereditary Hemochromatosis Algorithm in Special Instructions.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Ferritin is an acute phase reactant and may be elevated in patients with inflammation, liver disease, chronic infection, autoimmune disorders, and malignancy.

 

Ferritin may be elevated in excess iron storage disorders besides hemochromatosis including hemolytic anemia, sideroblastic anemia, and in those with multiple blood transfusions.

 

Race and ethnicity factors (especially in Native Africans, African Americans, and Asians) are also associated with higher mean concentrations of serum ferritin than are typical of whites, the basis of which is incompletely understood.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. McPherson RA, Pincus MR eds: Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Elsevier Saunders; 2007:506

2. Cappellinin MD, Lo SF, Swickels DW: Hemoglobin, iron, bilirubin. In: Rafai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier Saunders; 2018:719-775

Special Instructions Library of PDFs including pertinent information and forms related to the test