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HelpTest ID AMA Mitochondrial Antibodies (M2), Serum
Reporting Name
Mitochondrial Ab, M2, SUseful For
Establishing the diagnosis of primary biliary cirrhosis
Specimen Type
SerumSpecimen Required
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 0.5 mL
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 21 days |
| Frozen | 21 days |
Reference Values
Negative: <0.1 Units
Borderline: 0.1-0.3 Units
Weakly positive: 0.4-0.9 Units
Positive: ≥1.0 Units
Reference values apply to all ages.
Day(s) and Time(s) Performed
Monday through Saturday; 11 a.m.
Test Classification
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83516
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| AMA | Mitochondrial Ab, M2, S | 49781-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| AMA | Mitochondrial Ab, M2, S | 49781-8 |
Clinical Information
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.
Interpretation
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.
Clinical Reference
1. Rich RR, et al: Inflammatory hepatobiliary cirrhosis. In Clinical Immunology Principles and Practice. Third 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
Analytic Time
1 dayMethod Name
Enzyme Immunoassay (EIA)
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
General Request Form (T239) (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf)
Gastroenterology and Hepatology Test Request Form (T728) (http://www.mayomedicallaboratories.com/it-mmfiles/gastroenterology-and-hepatology-test-request.pdf)