Diagnostic Use
Serum ferritin is used as an indicator of the storage pool of iron. Its concentration in serum is approximately proportional to the total body iron stores, but only if the patient is otherwise healthy.
It is most useful for detecting iron deficiency, and a serum ferritin of < 15 ug/L generally indicates iron deficiency in an uncomplicated patient.
Causes for increased ferritin
- Iron overload
- Inflammation
- Liver disease
Ferritin is an acute phase protein (increases in inflammatory states). In infections, chronic inflammatory disorders, or malignancy the ferritin concentration may be normal, or even increased, even though the patient is iron deficient. It is therefore difficult to make the distinction between iron deficiency anaemia and anaemia of chronic disease, especially if both co-exist in the same patient. Measurement of soluble transferrin receptors may be helpful in this regard.
Ferritin is increased in iron overload; a normal or low ferritin almost certainly excludes iron overload. A high ferritin does not necessarily confirm it, if there is a co-existent inflammatory disorder or liver disease.
Recent iron infusion increase ferritin; usually peaking in the first 7 – 9 days and gradually decreasing over the next 3 months. Repeat iron studies during this period may be clinically confusing.
For IRON STUDIES, please refer to the following tests for more information:
- Total Iron Binding Capacity TIBC (Blood)
- Iron (Blood)
- Iron Saturation (Blood)
- Soluble Transferrin Receptors (Blood)
Reference Intervals
Units: ug/L
Ferritin results may vary significantly between laboratories.
Patients being serially monitored for iron overload should have ferritin levels measured by the same laboratory.
|
Age
|
Female
|
Male
|
|
0 – 4 months
|
15 – 400
|
15 – 400
|
|
5 – 11 months
|
15 – 80
|
15 – 80
|
|
1 – 14 years
|
15 – 150
|
15 – 150
|
|
15 – 19 years
|
15 – 170
|
15 – 170
|
|
20 – 30 years
|
20 – 170
|
20 – 320 *
|
|
30 – 40 years
|
20 – 190
|
20 – 400 *
|
|
Over 40 years
|
20 – 380 *
|
20 – 450 *
|
* NOTE: The upper normal limit for ferritin increases with age (see above). However, irrespective of age, values > 250 ug/L may be seen in inflammation, early iron overload, or liver disease, and should be accepted as normal only if these disorders have been excluded.
Test Method
Performed in Automation
Principle: Sandwich type immunoassay with chemiluminescence detection
Reagents: Roche assay
Analyser: Roche Cobas