Also known as:
Name: Caeruloplasmin
Related tests: Copper
Why is the test done?
To measure the amount of caeruloplasmin in the blood; to help diagnose Wilson’s disease; in some cases to help identify other conditions associated with copper deficiency.
When is the test done?
When you have jaundice, tiredness, abdominal pain, behavioural changes, tremors or other symptoms that the doctor thinks may be due to Wilson’s disease or, rarely, copper deficiency; it is done at intervals when monitoring is recommended.
What type of sample is required?
A blood sample taken from a vein in the arm.
What is being measured?
The test measures the amount of caeruloplasmin in the blood. Caeruloplasmin is a copper-containing enzyme that plays a role in iron metabolism. Copper is an essential mineral obtained from the diet. It is absorbed in the intestine and then carried to the liver, where it is stored or used to make various enzymes. The liver binds copper to apocaeruloplasmin to produce caeruloplasmin, which is then released into the bloodstream. About 95% of the copper in the blood is bound to caeruloplasmin. For this reason, caeruloplasmin can be measured together with one or more copper tests to help diagnose Wilson’s disease and assess copper metabolism.
How is the sample collected for testing?
A blood sample is taken by inserting a needle into a vein in the arm.
Is any preparation needed to ensure the quality of the sample?
No preparation is needed for this test.
1. How is it used?
2. When is it requested?
3. What does the result mean?
4. Is there anything else I should know?
1. How is it used?
Caeruloplasmin is mainly requested together with copper tests on blood and/or urine to diagnose Wilson’s disease, an inherited disease associated with low caeruloplasmin levels and excess storage of copper in the liver, brain and other organs. Rarely, it may be requested to help diagnose or distinguish between different conditions associated with copper deficiency.
2. When is it requested?
It is requested together with some copper tests when a patient has signs and symptoms that the doctor suspects may be due to Wilson’s disease, such as:
• Anaemia
• Nausea, abdominal pain
• Jaundice
• Tiredness
• behavioural changes
• tremor
• difficulty walking and/or swallowing
• dystonia
Rarely, caeruloplasmin may also be requested together with copper tests if your doctor suspects you may have copper deficiency, and it is done at intervals when monitoring is recommended.
3. What does the result mean?
Low caeruloplasmin levels are not diagnostic of a specific disease and so are usually assessed together with copper tests.
The test results can show several patterns
• If blood caeruloplasmin and copper concentrations are low and urine copper levels are high, the patient may have Wilson’s disease
• About 5% of patients with Wilson’s disease who have neurological symptoms, and 40% of those with liver symptoms, will have normal caeruloplasmin levels
• If caeruloplasmin and copper levels are low in both blood and urine, the patient may have copper deficiency
• Anything that interferes with the supply of copper or with the body’s ability to metabolise it can potentially affect blood caeruloplasmin and copper concentrations.
4. Is there anything else I should know?
Caeruloplasmin can be raised in a variety of circumstances in which the test is not used as a clinical tool. These may include:
• Caeruloplasmin is an acute phase protein. It is often raised with inflammation, severe infections and tissue damage, and may be raised with some types of cancer.
• It can be raised during pregnancy or by the use of oestrogens, oral contraceptives and medicines such as carbamazepine, phenobarbital and valproic acid.
Caeruloplasmin is not a routine test. Unless your doctor suspects you may have Wilson’s disease or a problem with copper metabolism, you are unlikely ever to have this test.
1. Is a liver biopsy necessary?
1. Is a liver biopsy necessary?
If Wilson’s disease is strongly suspected on the basis of urine and blood tests and imaging results, a liver biopsy may be carried out to assess the copper content of the liver.