ferritin in serum/plasma

Contraindications

• microcytic anemia in menstruating women with prior normal blood hemoglobin (MKSAP19)*

* treat for iron-deficiency anemia without testing (MKSAP19)

Reference interval

• adult male: 27 - 300 ng/mL
• adult female: 10 - 130 ng/mL*
• 15-200 ng/mL

* during childhood & age 55 & older, the sex difference is not apparent.

Principle

The IMx FERRITIN assay is based on the Microparticle Enzyme Immunoassay (MEIA) technology. The reagents are added to the reaction cell in the following sequence:

• The probe/electrode assembly delivers the sample, specimen Diluent, Anti-Ferritin Alkaline Phosphatase Conjugate, Coated Microparticles to the incubation well of the reaction cell.
• The enzyme-labeled antibody, ferritin & microparticles bind forming an 'Antibody-Antigen' Complex.
• An aliquot of the reaction mixture containing the antibody- antigen complex bound to the microparticles is transferred to the glass fiber matrix. The microparticles bind irreversibly to the glass fiber matrix.
• The matrix is washed to remove unbound materials.
• The substrate, 4-Methyllumbelliferyl Phosphate, is added to matrix & the fluorescent product is measured by the MEIA optical assembly.

Clinical significance

The availability of sensitive methods for measuring serum ferritin have significantly advanced the ability to detect iron deficiency & overload. Since iron deficiency is present before the onset of anemia, detection of an iron depleted state is important for control of nutritional anemia. Clinical assessment of iron stores has historically relied on the determination of serum iron, total iron-binding capacity (TIBC) & % transferrin (ratio of serum iron & TIBC) or direct examination of bone marrow.

Low serum ferritin (< 10 ng/mL) suggests depletion of total body iron stores, but a normal value does not exclude iron deficiency since ferritin is an acute phase reactant. There are other factors that influence serum ferritin levels because of other causes, such as, hepatocellular disease or iron therapy.

Ferritin is an acute phase reactant. Serum levels are increased in response to inflammation, although seldom > 400 ng/mL. Elevated serum ferritin may be a marker of macrophage activation. Ferritin tends to increase with age.

Serum ferritin > 100 ng/mL rules out iron deficiency anemia.

Values of serum ferritin > 800 ng/mL suggest hemochromatosis or Still's disease.

Increases

• fasting or inanition
  • sarcopenia
• acute leukemia
  • acute myeloblastic leukemia
  • acute lymphoblastic leukemia
• Hodgkin's disease
• inflammatory diseases
  • hemochromatosis
  • pulmonary infections
    • disseminated (including pulmonary) histoplasmosis (may be > 10,000 ug/L)
  • rheumatoid arthritis
    • Still's disease (values as high as 6000 ug/L or higher)
  • systemic lupus erythematosus (SLE)
  • burns
  • porphyria cutanea tarda
• acute & chronic hepatocellular diseases
  • alcoholic liver disease
  • inflammatory liver disease
• carcinoma of the breast

Decreases

• iron deficiency anemia

Specimen

• Serum specimens & plasma (heparin only) may be used.
• If the assay is to be performed within 24 hours after collection, the specimen should be stored in the refrigerator at 2-8 C. If the testing will be delayed more than 24 hours, the specimen should be frozen. Mix thoroughly after thawing to ensure consistency in the results. Avoid repeated freezing & thawing.
• Specimens showing particulate matter, erythrocytes, or turbidity should be centrifuged before testing.

SAMPLE VOLUME: 150 uL of specimen is the minimum volume required to perform the assay.

More general terms

• ferritin in body fluid

Additional terms

• ferritin

Component of

• iron studies
• endocrinology 7 analyte panel
• iron/hemochromatosis panel

Patient information

ferritin in serum/plasma patient information