Test Category: Specialist Biochemistry
Investigation Name:Copper – Urine
Alias or Abbreviation:Urine Cu, 24 hour urine copper excretion, penicillamine challenge test, post-penicillamine urine copper excretion
Accreditation:UKAS ISO15189:2022 accredited test: On scope
Intro:
Copper is an essential trace element, excess amounts of which are normally excreted in the bile. However, in conditions producing biliary impairment, and in Wilson’s Disease, disruption to normal Cu transport and storage within the body occurs leading to accumulation within the liver and increased urinary excretion.Urine copper measurement is useful in screening for, and diagnosis and monitoring of Wilson’s Disease. The diagnostic specificity may be increased in difficult cases by measuring urine copper both pre and post penicillamine chelation. Urine copper may also be a useful adjunct to serum copper in the investigation of acute copper poisoning. Measurement of urine copper is not useful in assessing Cu deficiency and here, serum or plasma copper must be used.
Pathology Laboratory:Trace Elements Laboratory
Requestable Seperately?Yes
Units: µmol/24 hours (24 hour collection)
nmol/mmol creatinine (spot urine)
Minimum Sample Volume:2 mL urine
Expected Turnaround Time:7 working days.
Urgent analysis where clinically indicated may be arranged directly with the laboratory.
Test Code:24CU (24 hour urine collection)
UCU (random urine)
Sample Type:
Diagnosis or monitoring of Wilson’s Disease:24h urine collection in polypropylene collection container or acid-rinsed polyethylene container.
Specimens can be aliquoted into a plain white -top universal container prior to transportation.
24 hour collection period dates, time and total volume MUST be recorded.
'Spot' urine samples are not acceptable (unless in very young children).
Investigation of acute toxicity & occupational monitoring:
Spot urine collected into a plain white -top universal container .
Complex Reference Range:24 hour urine copper:
All:
Less than 0.8 µmol/24h Cholestasis, hepatic cirrhosis, covert Wilson’s Disease
Greater than 0.8 µmol/24h
Acute hepatic crisis, frank Wilson’s Disease Greater than 1.6 µmol/24h
24 hour urine copper - post-penicillamine chelation:
Excretion post chelation will depend upon the dosing regimen used.
Thus for 500mg penicillamine given orally before, and again 12hr into a 24hr urine collection excretion is typically:
• Normal individual less than 12 µmol/24hr
• Wilson's Disease greater than 25 µmol/24hr
Random (spot) urine copper to creatinine ratio:
Less than 50 nmol/mmol creatinine
Collection Conditions / Other Information:To aid interpretation of results, please include the following information on the request form:
o If known Wilson’s Disease
o If samples are part of a penicillamine challenge test and whether they are pre or post penicillamine for correct result comments.
o If patient is on zinc therapy.
Referred to Another Laboratory?No
Storage Requirements:Store at 4 °C prior to dispatch
Posting Address / Requirements:Ambient temperature, 1st class post.
Sandwell Health Campus,
Specialist Chemistry,
Pathology Department,
Lyndon,
B71 4HJ
NPEX / PDF Reporting Available:Yes
EQA Scheme:UK NEQAS for Trace Elements
Further information:We are a designated Supra-Regional Assay Service (SAS) Laboratory for Trace Elements.
Lead Contact Details:Dr Nicola Barlow, Consultant Clinical Scientist,
SAS Director Trace Elements Laboratory
Email: nicola.barlow1@nhs.net
Email Address For Chasing Results:rwh-tr.bcpsspecialistchemistryenquiries@nhs.net
Methodology:Inductively coupled plasma mass spectrometry
Site Sample Tested:Sandwell Health Campus
Cost:Please email: bcpspathology.info@nhs.net for further details
Contact Number:0121 507 5162
