Home
HelpMayo Test ID TLUCR Thallium/Creatinine Ratio, Random, Urine
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 collection container with no metal cap or glued insert
Submission Container/Tube: Plastic, 10-mL urine tube or a clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 7 mL
Collection Instructions:
1. Collect a random urine specimen.
2. See Metals Analysis Specimen Collection and Transport for complete instructions.
Useful For
Detecting toxic thallium exposure in random urine specimens
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TLUC | Thallium/Creat Ratio, U | No | Yes |
| CRETR | Creatinine, Random, U | No | Yes |
Special Instructions
Method Name
TLUC: Inductively Coupled Plasma Mass Spectrometry (ICP-MS)
CRETR: Enzymatic Colorimetric Assay
Reporting Name
Thallium/Creat Ratio, Random, USpecimen Type
UrineSpecimen Minimum Volume
2.3 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.Clinical Information
Thallium is odorless, tasteless, and found in trace amounts in the earth's crust. It is used in the manufacturing of electronic devices, switches, and closures. It had previously been used in rodenticides. The greatest exposure can occur from eating food (eg, fruits and vegetables) since its easily taken up by plants through the roots. Cigarette smoking is also a source of exposure. Accidental ingestion may lead to vomiting, diarrhea, and leg pains, followed by a severe and sometimes fatal sensorimotor polyneuropathy. Peripheral neuropathy may occur within 1 week of exposure, while hair loss begins and continues for several weeks. Gastrointestinal symptoms, including pain, diarrhea, and constipation have also been reported in acute ingestion, along with myalgias, pleuritic chest pain, insomnia, optic neuritis, hypertension, cardiac abnormalities, Mees lines, and liver injury. Most thallium is excreted in the urine, can be found within an hour after exposure, and can be detected as long as two months after exposure.
Reference Values
THALLIUM:
0-17 years: Not established
≥18 years: <2 mcg/g creatinine
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
Patients exposed to high doses of thallium (>1 g) present with alopecia, peripheral neuropathy, and seizures, and kidney failure.
Normal daily thallium excretion is less than 1 mcg/day.
Exposed patients can have urine thallium excretion greater than 10 mcg/day. The long-term consequences of such an exposure are poor.
Cautions
No significant cautionary statements
Clinical Reference
1. Bank WJ, Pleasure DE, Suzuki K, Nigro M, Katz R. Thallium poisoning. Arch Neurol. 1972;26(5):456-464. doi:10.1001/archneur.1972.00490110090009
2. Pelclova D, Urban P, Ridson P, et al. Two-year follow-up of two patients after severe thallium intoxication. Hum Exp Toxicol. 2009;28(5):263-272. doi:10.1177/0960327109106487
3. Zhao G, Ding M, Zhang B, et al. Clinical manifestations and management of acute thallium poisoning. Eur Neurol. 2008;60(6):292-297. doi:10.1159/000157883
4. Strathmann FG, Blum LM. Toxic elements. In: Rifai N, Chiu RWK, Young I, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:455.e55
5. Campanella B, Colombaioni L, Benedetti E, et al. Toxicity of thallium at low doses: A review. Int J Environ Res Public Health. 2019;16(23):4732. doi:10.3390/ijerph16234732
Method Description
The metal of interest is analyzed by inductively coupled plasma mass spectrometry.(Unpublished Mayo method)
Creatinine:
The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus ver 2. Roche Diagnostics; V15.0, 03/2019)
Day(s) Performed
Tuesday, Friday
Report Available
2 to 5 daysSpecimen Retention Time
14 daysPerforming 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
83018
82570
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TLUCR | Thallium/Creat Ratio, Random, U | 13469-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CRETR | Creatinine, Random, U | 2161-8 |
| 615256 | Thallium/Creat Ratio, U | 13469-2 |