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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

Method Name

PBCU: Triple-Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS)

CRETR: Enzymatic Colorimetric Assay

Reporting Name

Lead/Creat Ratio, Random,U

Specimen Type

Urine

Specimen Minimum Volume

1.5 mL

Specimen Stability Information

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

Reference Values

LEAD/CREATININE:

0-17 years: Not established

≥18 years: <2 mcg/g creatinine

 

CREATININE:

≥18 years: 16-326 mg/dL

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

Interpretation

Measurements of urinary lead (Pb) levels have been used to assess lead exposure. However, like lead blood, urinary Pb excretion mainly reflects recent exposure and thus shares many of the same limitations for assessing lead body burden or long-term exposure.(1,2)

 

Urinary lead concentration increases exponentially with blood lead and can exhibit relatively high intra-individual variability, even at similar blood lead concentrations.(3,4)

Clinical Reference

1. Sakai T. Biomarkers of lead exposure. Ind Health. 2000;38(2):127-142

2. Skerfving S. Biological monitoring of exposure to inorganic lead. In: Clarkson TW, Friberg L, Nordberg GF, Sager PR, eds. Biological Monitoring of Toxic Metals. Rochester Series on Environmental Toxicity. Springer; 1988:169-197

3. Gulson BL, Jameson CW, Mahaffey KR, et al. Relationships of lead in breast milk to lead in blood, urine, and diet of the infant and mother. Environ Health Perspect. 1998;106(10):667-674

4. Skerfving S, Ahlgren L, Christoffersson JO. Metabolism of inorganic lead in man. Nutr Res. 1985;Suppl 1:601-607

5. Kosnett MJ, Wedeen RP, Rotherberg SJ, et al. Recommendations for medical management of adult lead exposure. Environ Health Perspect. 2007;115(3):463-471

6. de Burbane C, Buchet JP, Leroyer A, et al. Renal and neurologic effects of cadmium, lead, mercury, and arsenic in children: evidence of early effects and multiple interactions at environmental exposure levels. Environ Health Perspect. 2006;114(4):584-590

7. Strathmann FG, Blum LM: Toxic elements. In: Rifai N, Chiu RWK, Young I, Burnham CD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 44

8. Hauptman M, Bruccoleri R, Woolf AD. An update on childhood lead poisoning. Clin Pediatr Emerg Med. 2017;18(3):181-192. doi:10.1016/j.cpem.2017.07.010

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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

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