Copper (Cu); Cu (Copper); Metals, Tissue; Wilson's Disease
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Specimen handling should be minimized.
Elevated copper levels without supporting histology or other biochemical test results should instigate an investigation into whether the specimen has been contaminated.
A minimum tissue dry weight of 0.3 mg is required for analysis. This is the equivalent of a piece of tissue from a 22-gauge needle approximately 0.5 cm long, or approximately 0.3 cm in length when taken with an 18-gauge needle. Since the specimen must be manipulated during analysis, more than the minimal amount described in the previous sentence must be submitted for analysis.
Paraffin blocks that have been cut for slides may be contaminated if the microtome was previously used to cut specimens that had been fixed with a copper-containing solution. Many fixatives, such as Hollande's, contain high levels of copper. Any object that has been exposed to these fixatives (eg, cutting boards, towels, containers, utensils) and comes into contact with the tissue can potentially contaminate the specimen. Rinsing and washing will not remove the copper contaminant. Therefore, submission of fresh-frozen, unfixed tissue is strongly recommended.
The constellation of symptoms associated with Wilson disease (WD), which includes Kayser-Fleischer rings, behavior changes, and liver disease, is commonly associated with liver copper concentration above 250 mcg/g dry weight.
VERY HIGH >1000 mcg/g dry weight:
This finding is strongly suggestive of Wilson disease.
HIGH 250-1000 mcg/g dry weight:
This finding is suggestive of possible Wilson disease.
MODERATELY HIGH 50-250 mcg/g dry weight:
Excessive copper at this level can be associated with cholestatic liver disease, such as primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune hepatitis, and familial cholestatic syndrome. Heterozygous carriers for Wilson disease occasionally have modestly elevated values, but rarely higher than 125 mcg/g of dry weight. In general, the liver copper content is higher than 250 mcg/g dried tissue in patients with Wilson disease.
If any of the above findings are without supporting histology and other biochemical test results, contamination during collection, handling, or processing should be considered. Genetic testing for Wilson disease (WDZ / Wilson Disease, Full Gene Analysis, Varies) is available at Mayo Clinic Laboratories, call 800-533-1710 if you need additional assistance.
In patients with elevated levels of copper without supporting histology and other biochemical test results, contamination during collection, handling, or processing should be considered.