Test ID: AMA
Mitochondrial Antibodies (M2), Serum
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
Establishing the diagnosis of primary biliary cirrhosis
Method Name A short description of the method used to perform the test
Enzyme Immunoassay (EIA)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Antibodies to Microtubule Associated Protein 2
Antimitochondrial Antibodies
Immunology Profile (AMA)
Mitochondrial Antibodies, Serum
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:
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.5 mL
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 | Mild OK; Gross reject |
| Lipemia | Mild OK; Gross reject |
| Icterus | Mild OK; Gross OK |
| Other | NA |
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 |
|---|---|---|
| Serum | Refrigerated (preferred) | 21 days |
| Frozen | 21 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Antimitochondrial antibodies (AMAs) are detectable by indirect immunofluorescence in >90% of patients with primary biliary cirrhosis (PBC), but this method also detects AMAs of differing specificities in other diseases. The mitochondrial antigens recognized by AMAs in patients' sera have been classified numerically as M1 through M9, with the M2 antigen complex recognized by AMAs in sera from patients with PBC. M2 antigen is comprised of enzyme proteins of the 2-oxoacid dehydrogenase complex that are located on inner mitochondrial membranes. Included in this group of autoantigens are the pyruvate dehydrogenase complex, and 2-oxoglutarate dehydrogenase complex.
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.
Negative: <0.1 Units
Borderline: 0.1-0.3 Units
Weakly positive: 0.4-0.9 Units
Positive: > or =1.0 Units
Reference values apply to all ages.
Interpretation Provides information to assist in interpretation of the test results
Positive results for antimitochondrial antibody (AMA) of M2 specificity are highly specific for primary biliary cirrhosis (PBC), and false-negative results are rare.
A positive result for AMA of M2 specificity in a patient with clinical features of PBC is virtually diagnostic for this disease.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The level of antimitochondrial antibody (AMA) is not useful to indicate the stage or prognosis of the disease or for monitoring the course of disease. Positive results are found (infrequently) in patients with CREST (calcinosis, Raynaud’s phenomenon, esophageal hypomotility, sclerodactyly, and telangiectasia) syndrome, relatives of patients with primary biliary cirrhosis and other autoimmune diseases.
Supportive Data
Testing performed in the Immunology Antibody Laboratory of the antimitochondrial antibody (AMA)-M2 by EIA revealed a false-positive rate of <2% in normals and overall concordance compared with indirect immunofluorescence of 90% on sera from the Mayo primary biliary cirrhosis (PBC) Serum Bank. Ten discordant results were obtained (negative by EIA and positive by immunofluorescence assay). Seven of the 10 patients had no histologic evidence of PBC on liver biopsy.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Rich RR, et al: Infammatory hepatobiliary cirrhosis. In Clinical Immunology Principles and Practice. 3rd edition. Philadelphia, Elsevier, 2008
2. Muratori L, Granito A, Muratori P, et al: Antimitochondrial antibodies and other antibodies in primary biliary cirrhosis: diagnostic and prognostic value. Clin Liver Dis 2008;12:261-276
3. Kaplan MM, Gershwin ME: Primary biliary cirrhosis. N Engl J Med 2005;353(12):1261-1273
4. Van Norstrand MD, Malinchoc M, Lindor KD, et al: Quantitative measurement of autoantibodies to recombinant mitochondrial antigens in patients with primary biliary cirrhosis: relationship to levels of autoantibodies to disease progression. Hepatology 1997;25(1):6-11
Method Description Describes how the test is performed and provides a method-specific reference
Enzyme immunosorbent assay with purified M2 antigens. This method detects both IgG and IgM antibodies to M2 antigens. Testing is performed on theTriturus instrument by Grifols (Package insert: Bio-Rad, Kallestad Anti-Mitochondrial Kit, Distributed by Bio-Rad Laboratories, Inc., Hercules, CA)
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; 11 a.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.
83516
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 |
|---|---|---|
| AMA | Mitochondrial Ab, M2, S | 49781-8 |
External
link
PDF
document
Excel
document
Word
document