Clinical background:
Copper is a vital component of a number of metalloenzymes that are essential for human health. Ingested copper is mainly stored in the liver and removed via biliary excretion. Thus, cholestatic liver disease, e.g. primary biliary cirrhosis or primary sclerosing cholangitis, can cause an increase in serum copper levels. Copper circulates predominantly bound to caeruloplasmin, which is a positive acute phase reactant, i.e. copper levels increase during the systemic inflammatory (acute phase) response. Wilson’s disease is an inherited cause of copper excess where the liver fails to synthesise caeruloplasmin resulting in accumulation of copper in the liver and other tissues. Acquired copper deficiency is most commonly caused by intestinal disorders, inadequate TPN, and zinc over-supplementation. Menke’s disease is an inherited cause of copper deficiency. Increased urinary excretion of copper of up to 100 mg/24hour can be found in patients with Wilson’s disease and Menkes disease.
Specimen container paediatric:
Serum
Navy blue top ‘trace element’ tube with red-striped label – preferred sample if sufficient blood volume can be collected
White top plain tube (glass)
Urine
24-hour urine in acid-washed bottle
Specimen container adult:
Serum
Navy blue top ‘trace element’ tube with red-striped label
Available on request from Blood Sciences reception at both Freeman and RVI site
Urine
24-hour urine in acid-washed bottle
Minimum volume paediatric:
Serum: 1 mL blood
Urine: 1 mL urine
Minimum volume adult:
Serum: 1 mL blood
Urine: 1 mL urine
Special requirements:
Avoid contamination by dust.
Sample stability:
Serum and urine samples are stable at 2 to 4°C for up to 6 weeks or at -20°C indefinitely.
Transport requirements:
Ambient temperature.
Freq analysis:
Assay performed weekly.
Quality assurance:
Trace Element Quality Assurance Scheme (TEQAS) for Trace Elements
Interpretation:
| Low serum copper | Wilson’s disease (copper toxicity) Excess zinc or iron ingestion Long-term total parenteral nutrition in adults and children Malnourished children; premature infants Menke’s disease (copper deficiency) |
High serum copper | Primary biliary cirrhosis Primary sclerosing cholangitis Haemochromatosis Malignant diseases (including leukaemia) Thyrotoxicosis Acute phase response |
Low urine copper | Malnutrition/malabsorption Hypoproteinemias and nephrotic syndrome |
High urine copper | Wilson’s disease (copper toxicity) Menke’s disease (copper deficiency) Primary biliary cirrhosis Haemochromatosis Thyrotoxicosis Various infections and acute, chronic and malignant diseases (including leukaemia) Women taking OCP/oestrogen during pregnancy |
Reference ranges:
Serum
| Age | Copper (µmol/L) |
| <4 months | 1.4 – 7.2 |
| 4 to 6 months | 3.9 – 17.3 |
| 6 months to 9 years | 11.1 – 27.4 |
| 9 to 13 years | 11.2 – 23.7 |
| 13 to 19 years | 11.0 – 22.5 |
| >19 years | 11.0 – 25.1 |
Urine
| Age | Copper (µmol/24h) |
| All | <0.7 |
Factors affecting result:
Failure to adhere to correct specimen collection procedures can cause abnormal results due to specimen (dust) contamination, which can lead to misinterpretation and misdiagnosis.
Heparin may contain copper.
Other info:
Assay performed by ICP-MS in collision mode.