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Test Code PBUCR Lead/Creatinine Ratio, Random, Urine


Ordering Guidance


The Centers for Disease Control and Prevention recommends venous blood collection for lead testing; see PBDV / Lead, Venous, with Demographics, Blood.



Specimen Required


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

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine container with no metal cap or glued insert

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.


Useful For

Detecting clinically significant lead exposure, a toxic heavy metal, using random urine specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
PBCU Lead/Creatinine Ratio, U No Yes
CRETR Creatinine, Random, U No Yes

Reporting Name

Lead/Creat Ratio, Random,U

Specimen Type

Urine

Specimen Minimum Volume

1.5 mL

Specimen Stability Information

Specimen Type Temperature Time
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

LEAD/CREATININE:

0-17 years: Not established

≥18 years: <2 mcg/g creatinine

 

CREATININE:

0-17 years: Not established

≥18 years: 16-326 mg/dL

Method Description

Lead:

The metal of interest is analyzed by triple-quadrupole inductively coupled plasma mass spectrometry.(Unpublished Mayo method)

 

Creatinine:

This enzymatic method is based on the conversion of creatinine with the aid of creatininase, creatinase, and sarcosine oxidase to form glycine, formaldehyde, and hydrogen peroxide. Catalyzed by peroxidase the liberated hydrogen peroxide reacts with 4-aminophenazone and HTIB (2,4,6-triiodo03-hydroxybenzoic acid) to form a quinone imine chromogen. The color intensity of the quinone imine chromogen formed is directly proportional to the creatinine concentration in the reaction mixture.(Package insert: Creatinine plus ver.2. Roche Diagnostics; 07/2024)

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

83655

82570

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PBUCR Lead/Creat Ratio, Random,U 13466-8

 

Result ID Test Result Name Result LOINC Value
608904 Lead/Creatinine Ratio, U 13466-8
CRETR Creatinine, Random, U 2161-8

Day(s) Performed

Monday through Friday

Report Available

2 to 4 days