Copper
At a Glance
Why Get Tested?
To measure the amount of copper in the blood, urine, or liver; to help diagnose and monitor Wilson’s disease; sometimes to identify copper deficiencies and excesses
When to Get Tested?
When you have jaundice, fatigue, abdominal pain, behavioural changes, tremor, or other symptoms that your doctor thinks may be due to Wilson’s disease or, rarely, to copper deficiency or excess; at intervals when you are being treated for a copper-related condition
Sample Required?
A blood sample taken from a vein in your arm and/or a 24-hour urine sample; sometimes a liver biopsy sample
Test Preparation Needed?
No test preparation is needed
The Test Sample
What is being tested?
This test measures the amount of copper in the blood, urine, or liver (hepatic). Copper is an essential mineral that the body incorporates into enzymes. These enzymes play a role in the regulation of iron metabolism, formation of connective tissue, energy production at the cellular level, the creation of melanin, and the function of the nervous system and brain.
Copper is found in many foods including nuts, chocolate, mushrooms, shellfish, whole grains, dried fruits, and liver. Drinking water may acquire copper as it flows through copper pipes, and food may acquire it when people cook or serve food in copper dishes. Normally, the body absorbs copper from the intestines, makes it non-toxic by binding it to a protein, and transports it to the liver. The liver stores some of the copper and binds most of the rest to a protein called apocaeruloplasmin that, when copper is attached, becomes the enzyme caeruloplasmin. About 95% of the copper in the blood is bound to caeruloplasmin. The liver excretes excess copper into the bile and it is removed from the body in the stool. Some copper is also excreted in the urine.
Both excesses and deficiencies of copper are rare. Wilson’s disease, an inherited disorder, can lead to excess storage of copper in the liver, brain, and other organs. This can cause tissue damage and signs and symptoms such as:
- anaemia
- nausea, abdominal pain
- jaundice
- fatigue
- behavioural changes
- tremor
- difficulty walking and/or swallowing
- dystonia
If the kidneys are involved, then urine production may be decreased or absent. Some of these symptoms may also be seen with copper poisoning that is due to acute or chronic environmental exposure to copper or due to conditions such as liver disease or obstructions that prevent or inhibit copper metabolism and excretion.
Copper deficiencies may occasionally occur in patients who have conditions associated with severe malabsorption, such as cystic fibrosis and coeliac disease, and in infants exclusively fed cow-milk formulas. Symptoms may include neutropenia, osteoporosis, and microcytic anaemia. A rare X-linked genetic condition called Menkes kinky hair syndrome leads to copper deficiencies in the brain and liver of affected infants. The disease, which affects primarily males, is associated with seizures, delayed development, abnormal artery development in the brain, and unusual grey brittle kinky hair.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm and/or a 24-hour urine sample is collected. Sometimes a doctor performs a liver biopsy.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
The Test
How is it used?
Copper testing is primarily used to help diagnose Wilson’s disease. If a doctor suspects Wilson’s disease, then he/she would typically use a total and/or free (unbound) blood copper test alongside the caeruloplasmin concentration. If these tests are abnormal or equivocal, then they may be followed by a 24-hour urine copper test to measure copper excretion and a hepatic (liver) copper test to evaluate copper storage. Genetic testing may also be performed to detect mutations in the ATP7B gene if Wilson’s disease is suspected. However, these tests have limited availability and are usually performed in special reference or research laboratories.
If a doctor suspects copper toxicity, copper deficiency, or a disorder that is inhibiting copper metabolism, then he/she may use blood and/or urine copper tests along with caeruloplasmin to help evaluate the patient’s condition. One or more copper tests may be request to help monitor the effectiveness of treatment for Wilson’s disease, copper excess or copper deficiency.
When is it requested?
One or more copper tests are requested along with caeruloplasmin when someone has signs and symptoms that a doctor suspects may be due to Wilson’s disease, excess copper storage, copper poisoning, or due to a copper deficiency. These signs and symptoms may include:
- anaemia
- nausea, abdominal pain
- jaundice
- fatigue
- behavioural changes
- tremor
- difficulty walking and/or swallowing
- dystonia
One or more of the copper tests may be requested periodically when monitoring is recommended.
A hepatic copper test may be requested to further investigate copper storage when copper and ceruloplasmin results are abnormal or equivocal.
What does the test result mean?
Copper test results must be evaluated in context and are usually compared to caeruloplasmin concentration. Abnormal copper results are not diagnostic of a specific condition; they indicate the need for further investigation. Interpretation can be complicated by the fact that caeruloplasmin is an acute phase reactant – it may be elevated whenever inflammation or severe infections are present. Both caeruloplasmin and copper are also increased during pregnancyand with oestrogen and oral contraceptive use.
Test results may include:
Low blood copper concentrations along with increased urine copper excretion, low caeruloplasmin concentrations, and increased hepatic copper are typically seen with Wilson’s disease.
Increased blood and urine copper concentrations and normal or increased caeruloplasmin concentration may indicate exposure to excess copper or may be associated with conditions that decrease copper excretion – such as liver disease. Increased hepatic copper may be present with chronic conditions.
Decreased blood and urine copper concentrations and decreased caeruloplasmin may indicate a copper deficiency.
Normal hepatic copper may indicate that copper metabolism is functioning properly or that the distribution of copper in the patient’s liver is uneven and the sample is not representative of the person’s condition.
If a patient is being treated for excess copper storage with chelators, then the 24-hour urine copper concentrations may be high until body copper stores decrease. Eventually, blood copper and 24-hour urine copper concentrations should normalise.
If someone is being treated for a condition related to copper deficiency and his caeruloplasmin and total copper concentrations begin to rise, then it is likely that the condition is responding to the treatment.
Is there anything else I should know?
Medications such as oral contraceptives, carbamazepine and phenobarbital can increase blood copper concentration. They may also be elevated with rheumatoid arthritis and with some cancers, and decreased with a variety of conditions associated with malabsorption, such as cystic fibrosis.
Total serum copper concentrations are normally low at birth, rise over the next few years, peak, and then decline slightly to a relatively stable level.
Care must be taken, especially with a 24-hour urine sample, not to contaminate the sample with an external source of copper. Talk to your doctor and/or the laboratory that will perform your test about necessary precautions. If a urine or blood copper test result is higher than the doctor expects, then he may have you repeat the test to confirm the findings.
Common Questions
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Article Sources
NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
