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HelpTest Code CUU; SQ: COP24U Copper, 24 Hour, Urine
Reporting Name
Copper, 24 Hr, UUseful For
Investigation of Wilson disease and obstructive liver disease using a 24-hour urine specimen
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineNecessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Patient Preparation: High concentrations of barium are known to interfere with this test. If barium-containing contrast media has been administered, the specimen should not be collected for at least 96 hours.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine collection container with no metal cap or glued insert
Submission Container/Tube: Plastic urine tube or clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 10 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
3. See Metals Analysis Specimen Collection and Transport for complete instructions.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Special Instructions
Reference Values
0-17 years: Not established
≥18 years: 9-71 mcg/24 h
Day(s) Performed
Monday, Thursday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82525
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CUU | Copper, 24 Hr, U | 5633-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8590 | Copper, 24 Hr, U | 5633-3 |
| TM7 | Collection Duration | 13362-9 |
| VL4 | Urine Volume | 3167-4 |
Clinical Information
The biliary system is the major pathway of copper excretion. Biliary excretion of copper requires an adenosine triphosphate (ATP)-dependent transporter protein. Variants in the gene for the transporter protein cause hepatolenticular degeneration (Wilson disease). Ceruloplasmin, the primary copper-carrying protein in the blood, is also reduced in Wilson disease. Urine copper excretion is increased in Wilson disease due to a decreased serum binding of copper to ceruloplasmin or due to allelic variances in cellular metal ion transporters.
Hypercupricuria (increased urinary copper) is also found in hemochromatosis, biliary cirrhosis, thyrotoxicosis, various infections, and a variety of other acute, chronic, and malignant diseases (including leukemia). Urine copper concentrations are also elevated during pregnancy and in patients taking contraceptives or estrogens.
Low urine copper levels are seen in malnutrition, hypoproteinemias, malabsorption, and nephrotic syndrome. Increased zinc consumption interferes with normal copper absorption from the gastrointestinal tract causing hypocupremia.
Interpretation
Humans normally excrete less than 60 mcg/day of copper in the urine.
Urinary copper excretion greater than 60 mcg/day may be seen in:
-Wilson disease
-Obstructive biliary disease (eg, primary biliary cirrhosis, primary sclerosing cholangitis)
-Nephrotic syndrome (due to leakage through the kidney)
-Chelation therapy
-Estrogen therapy
-Mega dosing of zinc-containing vitamins
Because ceruloplasmin is an acute phase reactant, urine copper is elevated during acute inflammation. During the recovery phase, urine copper is usually below normal, reflecting the expected physiologic response to replace the copper that was depleted during inflammation.
Method Description
The metal of interest is analyzed by triple-quadrupole inductively-coupled plasma mass spectrometry.(Unpublished Mayo method)
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Triple-Quadrupole Inductively-Coupled Plasma-Mass Spectrometry (ICP-MS/MS)
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen: