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Test Code COBRU Cobalt/Creatinine Ratio, Random, Urine

Reporting Name

Cobalt/Creat Ratio, Random, U

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Detecting cobalt exposure in a random urine collection

 

Monitoring metallic prosthetic implant wear

 

This test is not useful for assessment of vitamin B12 activity.

Method Name

COBR: Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

CRETR: Enzymatic Colorimetric Assay


Ordering Guidance


High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.



Specimen Required


Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 10-mL urine tube or 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 Metals Analysis Specimen Collection and Transport for complete instructions


Specimen Type

Urine

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  14 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

COBALT:

0-17 years: Not established

>17 years: <1.7 mcg/g Cr

 

CREATININE:

≥18 years old: 16-326 mg/dL

Reference values have not been established for patients who are younger than 18 years of age.

Interpretation

Concentrations greater or equal to 2.0 mcg/g creatinine indicate excess exposure. There are no Occupational Safety and Health Administration blood or urine criteria for occupational exposure to cobalt.

 

Prosthesis wear is known to result in increased circulating concentration of metal ions. In a patient with a cobalt-based implant, modest increase (2-4 mcg/g creatinine) in urine cobalt concentration is likely to be associated with a prosthetic device in good condition. Excessive exposure is indicated when urine cobalt concentration is greater than 5 mcg/g creatinine, consistent with prosthesis wear. Urine concentrations greater than 20 mcg/g creatinine in a patient with a cobalt-based implant suggest significant prosthesis wear. Increased urine trace element concentrations in the absence of corroborating clinical information do not independently predict prosthesis wear or failure.

Day(s) Performed

Tuesday, Wednesday, Friday

Report Available

1 to 4 days

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

83018

82570

LOINC Code Information

Test ID Test Order Name Order LOINC Value
COBRU Cobalt/Creat Ratio, Random, U 13468-4

 

Result ID Test Result Name Result LOINC Value
607272 Cobalt/Creat Ratio, U 13468-4
CRETR Creatinine, Random, U 2161-8

Profile Information

Test ID Reporting Name Available Separately Always Performed
COBR Cobalt/Creat Ratio, U No Yes
CRETR Creatinine, Random, U No Yes