Test ID: MYOU
Myoglobin, Urine
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Confirming the presence of a myopathy associated with any 1 of the above disorders
May suggest a myopathic cause for acute renal failure
Follow-up testing for specimens with positive urine hemoglobin results by the dipstick method
Method Name A short description of the method used to perform the test
Latex Particle-Enhanced Immunonephelometry
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Plastic, 10-mL urine tube (Supply T068)
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Additional Information: Myoglobin deteriorates by 25%/day in all acceptable preservatives. Clinically significant elevations are seen in the thousands, however, and should not confuse interpretation.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Acidified urine |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 7 days |
| Frozen | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Myoglobin is the oxygen-binding protein of striated muscle. Injury to skeletal or cardiac muscle results in the release of myoglobin. High concentrations appear very rapidly in the urine in various conditions including some metabolic diseases. Conditions associated with myoglobinuria include:
-Hereditary myoglobinuria
-Phosphorylase deficiency
-Sporadic myoglobinuria
-Exertional myoglobinuria in untrained individuals
-Crush syndrome
-Myocardial infarction
-Myoglobinuria of progressive muscle disease
-Heat injury(1,2)
Urine myoglobin increases with muscle necrosis, but the clinical consequences are variable. Therefore, myoglobin can confirm a clinical diagnosis of myopathy, but an elevated urine excretion of myoglobin is not specific for a clinical disorder.(1,2)
In acute renal failure, an elevated urinary myoglobin can suggest a potential cause and, consequently, may indicate appropriate treatment courses.
Urine myoglobin cross-reacts with standard urine dipstick tests for hemoglobin (false-positive). If the dipstick is positive for hemoglobin but the urine contains no or few RBCs, the urine myoglobin test may help confirm or rule out hemoglobinuria.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
<0.025 mcg/mL
Reference values apply to all ages.
Interpretation Provides information to assist in interpretation of the test results
Increased excretion of urinary myoglobin suggests the disorders listed above.
Most clinically significant elevations are elevated 2 to 10 times normal.
Visual pigmenturia occurs at myoglobin concentrations is about 160 times normal (approximately 4 mcg/mL).
Renal toxicity depends on multiple factors such as renal perfusion and degree of acidity of urine.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
An elevated level of myoglobin in urine does not identify the clinical disorder.
Urine collected with acid as preservative will not be valid because acid interferes with antibody binding.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Rowland LP: Mylglobinuria, 1984. Can J Neurol Sci 1984;11:1-13
2. Tonin P, Lewis P, Servidei S, et al: Metabolic causes of myoglobinuria. Ann Neurol 1990;27:181-185
Method Description Describes how the test is performed and provides a method-specific reference
This method uses polystyrene particles coated with specific antibodies to human myoglobin. When mixed with samples or standards, an insoluble complex is formed causing light, at 840 nm, to be scattered. The intensity of scattered light is dependent on the amount of myoglobin present. The myoglobin concentration in the sample is calculated from standards of known concentration. (Borque L, Rus A, Ruiz R: Quantitative automated latex nephelometric immunoassay for determination of myoglobin in human serum. J Clin Lab Anal 1991;5:175-179; Massoubre C, Chivot L, Mainard F, et al: Immunonephelometric assay of myoglobin. Clin Chim Acta 1991;201:223-229)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday 3 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
83874
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| MYG_L | Myoglobin, U | 2641-9 |
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