Test ID: MNCRU Manganese/Creatinine Ratio, Random, Urine
Reporting Name
Manganese/Creat Ratio, Random, UUseful For
Monitoring manganese exposure
Nutritional monitoring
Clinical trials
Clinical Information
Manganese (Mn) is an essential trace element with many industrial uses. Manganese is the 12th most abundant element in the earth's crust and is used predominantly in the production of steel. These industrial processes cause elevated environmental exposures to airborne manganese dust and fumes, which in turn have led to well-documented cases of neurotoxicity among exposed workers. Mining and iron and steel production have been implicated as sources of exposure.
Inhalation is the primary source of entry for manganese toxicity. Signs of toxicity may appear quickly or not at all; neurological symptoms are rarely reversible. Manganese toxicity is generally recognized to progress through 3 stages. Levy describes these stages. "The first stage is a prodrome of malaise, somnolence, apathy, emotional lability, sexual dysfunction, weakness, lethargy, anorexia, and headaches. If there is continued exposure, progression to a second stage may occur, with psychological disturbances, including impaired memory and judgment, anxiety, and sometimes psychotic manifestations such as hallucinations. The third stage consists of progressive bradykinesia, dysarthrian axial and extremity dystonia, paresis, gait disturbances, cogwheel rigidity, intention tremor, impaired coordination, and a mask-like face. Many of those affected may be permanently and completely disabled."(1)
Few cases of manganese deficiency or toxicity due to ingestion have been documented. Only 1% to 3% manganese is absorbed via ingestion, while most of the remaining manganese is excreted in the feces. As listed in the United States National Agriculture Library, manganese adequate intake is 1.6 to 2.3 mg/day for adults. This level of intake is easily achieved without supplementation by a diverse diet including fruits and vegetables, which have higher amounts of manganese than other food types. Patients on a long-term parenteral nutrition should receive manganese supplementation and should be monitored to ensure that circulatory levels of manganese are appropriate.
Interpretation
Manganese in urine represents the excretion of excess manganese from the body, and may be used to monitor exposure or excessive nutritional intake.
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
MNCR | Manganese/Creat Ratio, U | No | Yes |
CDCR | Creatinine Conc | No | Yes |
Special Instructions
Analytic Time
1 dayDay(s) and Time(s) Performed
Thursday
Clinical Reference
1. Levy BS, Nassetta WJ: Neurologic effects of manganese in humans: A review. Int J Occup Environ Health. 2003 Apr-Jun;9(2):153-163
2. Paschal DC, Ting BG, Morrow JC, et al: Trace metals in urine of United States residents: reference range concentrations. Environ Res. 1998 Jan;76(1):53-59
Method Name
MNCR: Dynamic Reaction Cell-Inductively Coupled Plasma-Mass Spectrometry (DRC-ICP-MS)
CDCR: Enzymatic Colorimetric Assay
Specimen Type
UrineSpecimen Required
Patient Preparation: High concentrations of gadolinium and iodine are known to interfere with most metals 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
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 Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.
Specimen Minimum Volume
0.8 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 7 days |
Reference Values
<4.0 mcg/g creatinine
Reference values have not been established for patients that are <18 years of age.
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
83785 Manganese Concentration
82570 Creatinine Concentration
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
MNCRU | Manganese/Creat Ratio, Random, U | 27367-2 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
CDCR | Creatinine Conc | 2161-8 |
32867 | Manganese/Creat Ratio, U | 27367-2 |
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