Ferritin

Ferritin is a large multi-subunit protein whose main function is to store iron, thus creating a reservoir that the body can use for its multiple requirements. After hemoglobin, the vast majority of iron in the body is stored in the crystalline core of ferritin. While ferritin can be found in all tissues of the body, it’s primarily found in the liver, spleen and bone marrow¹. Holoferritin is the term used to refer to ferritin fully loaded with iron, whereas apoferritin refers to the protein alone. A partially degraded form of ferritin is known as hemosiderin.

The main biological function of ferritin is to help regulate iron homeostasis. Consequently, testing serum ferritin can provide useful information on a patient’s iron status. Other tests which aid in understanding a patient’s iron status include: total serum iron, total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC), and the iron transport protein, transferrin^2-9. Ferritin is a versatile clinical analyte and has applications aside from its role as an indicator of iron status. Some examples include the diagnosis of Still’s Disease¹⁰, and the prognosis and management of various cancers such as neuroblastoma^11,12, Hodgkin’s Disease¹³, lung cancer¹⁴ and laryngeal cancer¹⁵.

REFERENCES

1. 1. Burtis, C.A., Ashwood, E.R. and Bruns, E.R. Tietz Textbook of Clinical Chemistry, 4th Edition, W.B. Saunders Company, 2006.
2. 2. Ferritin in Serum: Diagnosis of Iron Deficiency and Iron Overload in Infants and Children. Blood, 43, 581-590, 1974.
3. 3. Puolakka, J., et. al. Serum Ferritin in the Diagnosis of Anemia During Pregnancy. Acta Obstet Gynecol Scand, 59, 57-63, 1980.
4. 4. Singer, J. Diagnosis of Iron-Deficiency in the Elderly. The American Journal of Medicine, 88, 205-209, 1990.
5. 5. Guyatt, G.H., et. al. Laboratory Diagnosis of Iron-Deficiency Anemia: An Overview. J Gen Intern Med, 7, 145-153, 1992.
6. 6. Gasche, C., et. al. Guidelines on the Diagnosis and Management of Iron Deficiency and Anemia in Inflammatory Bowel Diseases. Inflammatory Bowel Diseases, 13, 1545-1553, 2007.
7. 7. Iron Deficiency Anemia: Diagnosis and Management. Current Opinion in Gastroenterology, 25, 122-128, 2009.
8. 8. Lawrie, W.P., et. al. Diagnosis of Hemochromatosis, Annals of Internal Medicine, 129, 925-931, 1998.
9. 9. Crawford, D.H.G., et. al. Serum Hyaluronic Acid with Serum Ferritin Accurately Predicts Cirrhosis and Reduces the Need for Liver Biopsy in C282Y Hemochromatosis. Hepatology, 49, 418-425, 2009.
10. 10. Fautrel, B., et. al. Diagnostic Value of Ferritin and Glycosylated Ferritin in Adult Onset Still's Disease. The Journal of Rheumatology, 28, 322-329, 2001.
11. 11. Seeger, R.C., et.al. Association of Multiple Copies of the N-myc Oncogene with Rapid Progression of Neuroblastomas, N Engl J Med, 313, 1111-1116, 1985.
12. 12. Hann, H.W.L., et. al. Prognostic Importance of Serum Transferrin and Ferritin in Childhood Hodgkin's Disease. Cancer, 66, 313-316, 1990.
13. 13. DuBois, S.G., et. al. Metastatic Sites in Stage IV and IVS Neuroblastoma Correlate with Age, Tumor Biology and Survival. J Pediatr Hematol Oncol, 21, 181-189, 1999.
14. 14. Milman, N. and Pedersen, L.M. The Serum Ferritin Concentration is a Significant Prognostic Indicator of Survival in Primary Lung Cancer. Oncology Reports, 9, 193-198, 2002.
15. 15. Mevio, E., et. al. Use of Serum Markers in the Diagnosis and Management of Laryngeal Cancer. Clinical Otolaryngology, 16, 90-92, 1991.