Ferritin, Serum
The Ferritin, Serum blood test is used to diagnose hypochromic, microcytic anemias, decreases in iron deficiency anemia and increases in iron overload. Ferritin levels correlate with and are useful in evaluation of total body storage iron. In hemochromatosis, both ferritin and iron saturation are increased. Ferritin levels in hemochromatosis may be >1000 ng/mL.
Additional information:
The serum ferritin is, other than a bone marrow examination, the most reliable indicator of total body iron stores. When combined with the serum iron and percent saturation of iron binding capacity/transferrin, it can usually differentiate the microcytic hypochromic anemias into iron deficiency anemia (ferritin low, iron low, saturation low, TIBC high, transferrin high), the anemia of chronic disease (ferritin normal or high, iron low, normal to low transferrin or TIBC), or thalassemia (ferritin normal or high). Ferritin is low with combined iron deficiency and thalassemia. In adults, serum ferritin level ≤10 ng/mL indicates iron deficiency. High serum ferritin levels may be associated with inflammation, liver disease, megaloblastic anemia, hemolytic anemia, sideroblastic anemia, thalassemia, iron overload (hemochromatosis, hemosiderosis), malignant diseases including leukemia and malignant lymphoma and are described with CEA elevations in patients with breast cancer. Very high levels indicate iron overload. Oral and injected iron increase ferritin levels. Increased serum ferritin may be a risk factor in primary hepatocellular carcinoma.
Primary hemochromatosis is inherited in an autosomal recessive manner with preliminary evidence that the involved gene is linked to the A locus of the histocompatibility complex on chromosome 6. Inappropriate increase in iron absorption and parenchymal tissue deposition eventuates in hepatic cirrhosis, diabetes, testicular atrophy, and fine, soft, bronze to slate gray skin and very high serum ferritin levels (usually >1000 ng/mL).
Red cell ferritin in conjunction with serum ferritin may be useful in distinguishing iron deficiency from iron overload in patients who have β-thalassemia.
The decline in serum ferritin occurring during adolescence has been shown to be due to the onset of menarche rather than as a result of the accompanying growth spurt.
Elevated serum ferritin levels in patients with cancer is associated with a poor prognosis which may be due in part to deleterious biological effects of tumor ferritins on lymphocyte and granulocyte function. Extensive data is accumulating on the nature of isoferritins and their association with and possible utilization in the evaluation of malignant neoplasia.