Ferritin

DESCRIPTION:
Ferritin is a protein with a molecular weight of about 440,000 daltons (depending on the iron content). It consists of 24 identical subunits. In the center of ferritin there is iron surrounded by protein subunits (apoferritin). Ferritin contains more than 2000 to 4500 iron atoms in the form of ferric hydroxide phosphate. Ferritin is a protein that stores iron. Ferritin is not only an important parameter for the diagnosis of iron deficiency anemia, but also for the recognition of hemochromatosis. Also, ferritin is attributed importance as a tumor marker. About 20 isoferritins are known to exist. Basic isoferritins are rich in iron and are mainly found in the liver, spleen and bone marrow. Acidic isoferritins are low in iron and are found in placenta, heart and tumor cells. The level of serum ferritin is directly proportional to the amount stored in the body. Ferritin serves as a storehouse of iron in a form that can be easily mobilized according to the body’s needs. Ferritin is found in the liver, spleen and bone marrow, and in very small amounts in the blood. The amount of ferritin in the blood can help estimate how much iron is stored in the body.

DETERMINATION:
Determination method: CMIA. Sample: serum or plasma (EDTA or heparin). The stability of the sample is 7 days at 2-8°C, 12 months at -10°C or at a lower temperature.

CLINICAL SIGNIFICANCE:
Determination of ferritin is primarily used in the diagnosis of iron metabolism disorders. Recently, however, ferritin has also been used as a tumor marker. An elevated value of ferritin in malignant processes is most likely due to cell necrosis, blockage of erythropoiesis or direct formation in tumor tissues.

RISK FACTORS: Reduced values:
Blood donors Malnutrition Operative procedures Peritoneal dialysis (outpatient) Older age Pregnancy
Increased values:
Alcoholism – alcoholics Physical effort (e.g. marathon runners) Lipemia Menopause Cloudiness Body position: In a patient who is standing or holding his arm vertically in relation to the body, ferritin values are 10% higher compared to a patient in a lying position. Smoking Eating large amounts of meat Variation from day to day in men 13.9 micro g/L and 25.8 micro g/L in women during menstruation

EFFECT OF DRUGS: Reduced values:
Biologically reduced values: propylthiouracil, thiamazole (methimazole), deferoxamine
Increased values:
Biologically increased values: ferric-hydroxy polymaltose complex (Ferro Lek), ferrous sulfate, iron dextran complex, oral contraceptives, theophylline

RESULT:
The reference range depends on gender, age and the method of determination. The reference interval is displayed on each validated result.