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PTD - 210

Test Directory -  Urinary Copper

Clinical Indications

The sensitivity and specificity of this test are suboptimal for use as a screening test for Wilson's disease (see caeruloplasmin) but it may be useful to confirm the diagnosis and to evaluate response to chelation therapy.

Measuring urinary copper excretion before and after administration of 2 x 500 mg oral doses of penicillamine at 12 hour intervals can help to distinguish children with Wilson's disease from those with liver disease due to other causes. A protocol for this is available

Request Form

Combined Pathology Blood form (Yellow/Black)

Availability

Analysed by the Trace Element Laboratory, Guildford if specific criteria met.

Specific Criteria

Confirmation of suspected Wilson's disease, evaluation of response to chelation therapy or as part of penicillamine challenge test.

Patient Preparation

None required

Turnaround Time

2 weeks

Specimen

Acid-washed 24hr urine container

Volume

24hr Collection

Container

Acid-washed 24hr urine container. Please contact Clinical Biochemistry to arrange for a container.

Causes for Rejection

Not meeting specific criteria for analysis. Collection into a container that has not been acid washed (contamination).

Reference Range

Normal adults: less than 0.9 umol/24hr.
Wilson's disease: greater than 1.6 umol/24hr.

Interpretation

The urinary copper excretion rate is elevated in most patients with symptomatic Wilson's disease.

Lab. Handling

Processing: Record the 24hr volume and pH. Aliquot into a universal container and store at 4C in separating fridge (CB39).
Referral: UCU and send or BPRO and save in separating freezer (CB40) at
-20C.

     

Version 1.0 / April 2014                                                                                                          Approved by: Consultant Biochemist