Ferritin is a protein that stores iron in tissues. The small amounts of ferritin that escape from the cells reflect the total iron reserves available for haemoglobin synthesis. Ferritin levels are interpreted taking into account other tests (serum iron, transferrin, TIBC, iron saturation, hemoglobin, hematocrit).
Ferritin levels are lower when iron reserves are insufficient, sometimes even before clinical signs and symptoms appear. Lower ferritin levels are the best indicator of iron deficiency.
Ferritin levels are high in individuals with hemochromatosis, a relatively common inherited disease caused by accelerated iron absorption into the intestine. Excess iron is deposited in tissues including the liver, pancreas and other organs causing impairment problems. High levels of ferritin are also observed in polytransfused individuals or people who suffer from inflammation, liver disease, chronic infections, autoimmune diseases and certain types of cancer. When ferritin-containing organs are damaged (liver, spleen, bone marrow), they can release significant amounts of ferritin into the blood. In this case, the blood ferritin level does not adequately reflect iron reserves.