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Test Code PBCU Lead/Creatinine Ratio, Urine


Specimen Required


Only orderable as part of profile. For more information see:

-PBUCR / Lead/Creatinine Ratio, Random, Urine

-HMUCR / Heavy Metal/Creatinine Ratio, with Reflex, Random, Urine


Secondary ID

608904

Useful For

Detecting clinically significant lead exposure using random urine specimens

 

This test is not a substitute for blood lead screening.

Method Name

Only orderable as part of profile. For more information see:

-PBUCR / Lead/Creatinine Ratio, Random, Urine

-HMUCR / Heavy Metal/Creatinine Ratio, with Reflex, Random, Urine

 

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

Reporting Name

Lead/Creatinine Ratio, U

Specimen Type

Urine

Specimen Minimum Volume

1.5 mL

Specimen Stability Information

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

Reject Due To

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

Clinical Information

Increased urine lead concentration per gram of creatinine indicates significant lead exposure. Measurement of urine lead concentration per gram of creatinine before and after chelation therapy have been used as an indicator of significant lead exposure. An increase in lead concentration per gram of creatinine in the post-chelation specimen of up to 6 times the concentration in the pre-chelation specimen is normal.

 

Blood lead is the best clinical correlation of toxicity.

 

For more information see PBDV / Lead, Venous, with Demographics, Blood.

Reference Values

Only orderable as part of profile. For more information see:

-PBUCR / Lead/Creatinine Ratio, Random, Urine

-HMUCR / Heavy Metal/Creatinine Ratio, with Reflex, Random, Urine

 

0-17 years: Not established

≥18 years: <2 mcg/g creatinine

Interpretation

Urinary excretion of less than 4 mcg/g creatinine is not associated with any significant lead exposure.

 

Urinary excretion greater than 4 mcg/g creatinine is usually associated with pallor, anemia, and other evidence of lead toxicity.

 

Measurements of urinary lead levels have been used to assess lead exposure. However, like lead blood, urinary lead 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)

Cautions

No significant cautionary statements

Clinical Reference

1. Sakai T. Biomarkers of lead exposure. Ind Health. 2000;38(2):127-142. doi:10.2486/indhealth.38.127

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):667-667. doi:10.1289/ehp.98106667

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. doi:10.1289/ehp.9784

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. doi:10.1289/ehp.8202

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

Method Description

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

Specimen Retention Time

14 days

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.

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PBCU Lead/Creatinine Ratio, U 13466-8

 

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

Day(s) Performed

Monday through Friday

Report Available

2 to 4 days

CPT Code Information

83655