Ferritin

Function

Ferritin is a universal intracellular protein that stores iron and releases it in a controlled fashion. It acts as a buffer against iron deficiency and iron overload. While most ferritin is found inside cells, a small amount circulates in the blood, which serves as an accurate reflection of the body's total iron stores.

Why it is Ordered

Physicians order a Ferritin test to evaluate iron metabolism. It is the most sensitive marker for detecting iron deficiency anemia in its early stages, often before hemoglobin levels drop. Conversely, it is used to monitor conditions of iron overload, such as hemochromatosis. Because ferritin is also an 'acute-phase reactant,' it may be ordered to assess inflammation or chronic disease states.

Associated Conditions

• Iron Deficiency Anemia: Low ferritin is almost always diagnostic of depleted iron stores.
• Hemochromatosis: A genetic condition leading to excessive iron absorption.
• Chronic Diseases: Conditions like rheumatoid arthritis or certain cancers can elevate ferritin levels.
• Liver Disease: Since the liver is a primary storage site for ferritin, hepatic inflammation can cause the protein to leak into the bloodstream.
• Restless Legs Syndrome (RLS): Low iron levels in the brain, often reflected by low serum ferritin, are linked to RLS symptoms.