Home
HelpTest ID CUCRU Copper/Creatinine Ratio, Random, Urine
Useful For
Investigation of Wilson disease and obstructive liver disease
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| CUCR | Copper/Creat Ratio, U | No | Yes |
| CDCR | Creatinine Conc | No | Yes |
Special Instructions
Method Name
CUCR: Dynamic Reaction Cell-Inductively Coupled Plasma-Mass Spectrometry (DRC-ICP-MS)
CDCR: Enzymatic Colorimetric Assay
Reporting Name
Copper/Creat Ratio, Random, USpecimen Type
UrineCollection Container/Tube: Clean, plastic urine collection container
Submission Container/Tube: Plastic, 10-mL urine tube (Supply T068) or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 3 mL
Collection Instructions:
1. Collect a random urine specimen.
2. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.
Additional Information: High concentrations of barium are known to interfere with most metals tests. If barium-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Specimen Minimum Volume
0.7 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 28 days |
| Ambient | 28 days | |
| Frozen | 28 days |
Clinical Information
The biliary system is the major pathway of copper excretion. Biliary excretion of copper requires an ATP-dependent transporter protein. Mutations 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.
Hypercupriuria is also found in Menkes disease (kinky hair disease), hemochromatosis, biliary cirrhosis, thyrotoxicosis, various infections, and a variety of other acute, chronic, and malignant diseases (including leukemia). Urine copper concentrations are also elevated in patients taking contraceptives or estrogens and during pregnancy.
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.
Reference Values
≥16 years: 15-60 mcg/g Creatinine
Reference values have not been established for patients that are <16 years of age.
Cautions
High concentrations of barium are known to interfere with this test. If barium-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Day(s) Performed
Tuesday, Thursday; 8 a.m.
Report Available
1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
See Individual Test IDsCPT Code Information
82525