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Test Code ASCU Arsenic/Creatinine Ratio, Urine


Specimen Required


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

-ASUCR / Arsenic/Creatinine Ratio, with Reflex, Random, Urine

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


Useful For

Screening for arsenic exposure using random urine specimens

Testing Algorithm

If total arsenic concentration is 10 mcg/L or greater, then speciation will be performed at an additional charge.

Method Name

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

-ASUCR / Arsenic/Creatinine Ratio, with Reflex, Random, Urine

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

 

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

Reporting Name

Arsenic/Creatinine Ratio, U

Specimen Type

Urine

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reference Values

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

-ASUCR / Arsenic/Creatinine Ratio, with Reflex, Random, Urine

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

 

0-17 years: Not established

≥18 years: <24 mcg/g creatinine

Interpretation

Physiologically, arsenic exists in a number of toxic and nontoxic forms. The total arsenic concentration reflects all the arsenic present in the sample regardless of species (eg, inorganic vs. methylated vs. organic arsenic). The measurement of urinary total arsenic levels is generally accepted as the most reliable indicator of recent arsenic exposure. However, if the total urine arsenic concentration is elevated, arsenic speciation must be performed to identify if it is the toxic forms (eg, inorganic and methylated forms) or the relatively nontoxic organic forms (eg, arsenobetaine and arsenocholine).

 

The inorganic toxic forms of arsenic (eg, As[III] and As[V]) are found in the urine shortly after ingestion, whereas the less toxic methylated forms monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), are the species that predominate longer than 24 hours after ingestion. In general, urinary As[III] and As[V] concentrations peak in the urine at approximately 10 hours and return to normal 20 to 30 hours after ingestion. Urinary MMA and DMA concentrations normally peak at approximately 40 to 60 hours and return to baseline 6 to 20 days after ingestion.

 

This test can determine if a patient has been exposed to above-average levels of arsenic. It cannot predict whether the arsenic levels in their body will affect their health.

Clinical Reference

1. Fillol CC, Dor F, Labat L, et al. Urinary arsenic concentrations and speciation in residents living in an area with naturally contaminated soils. Sci Total Environ. 2010;408(5):1190-1194. doi:10.1016/j.scitotenv.2009.11.046

2. Caldwell KL, Jones RL, Verdon CP, Jarrett JM, Caudill SP, Osterloh JD: Levels of urinary total and speciated arsenic in the US population: National Health and Nutrition Examination Survey 2003-2004. J Expo Sci Environ Epidemiol. 2009;19(1):59-68. doi:10.1038/jes.2008.32

3. Agency for Toxic Substances and Disease Registry: Toxicological profile for arsenic. US Department of Health and Human Services; 2007. Available at www.atsdr.cdc.gov/ToxProfiles/tp2.pdf

4. 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

5. Keil DE, Berger-Ritchie J, McMillin GA. Testing for toxic elements: A focus on arsenic, cadmium, lead, and mercury. Lab Med. 2011; 42(12):735-742. doi:10.1309/LMYKGU05BEPE7IAW

6. Navas-Acien A, Francesconi KA, Silbergeld EK, Guallar E. Seafood intake and urine concentrations of total arsenic, dimethylarsinate and arsenobetaine in the US population. Environ Res. 2011;111(1):110-118. doi:10.1016/j.envres.2010.10.009

7. Tchounwou PB, Yedjou CG, Udensi UK, et al. State of the science review of the health effects of inorganic arsenic: Perspectives for future research. Environ Toxicol. 2019;34(2):188-202. doi:10.1002/tox.22673

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
ASCU Arsenic/Creatinine Ratio, U 13463-5

 

Result ID Test Result Name Result LOINC Value
608900 Arsenic/Creatinine Ratio, U 13463-5
608901 Total Arsenic Concentration 5586-3

Day(s) Performed

Monday through Friday

Report Available

2 to 4 days

CPT Code Information

82175