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Test ID AMA Mitochondrial Antibodies (M2), Serum

Reporting Name

Mitochondrial Ab, M2, S

Useful For

Establishing the diagnosis of primary biliary cirrhosis

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen 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 (AMA) are detectable by indirect immunofluorescence in more than 90% of patients with primary biliary cirrhosis (PBC), but this method also detects AMA of differing specificities in other diseases. The mitochondrial antigens recognized by AMA in patients' sera have been classified numerically as M1 through M9, with the M2 antigen complex recognized by AMA 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.

Cautions

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.

Clinical Reference

1. Rich R, Fleisher T, Shearer W, et al: Inflammatory hepatobiliary cirrhosis. In Clinical Immunology Principles and Practice. Third edition. Philadelphia, Elsevier 2008 April 15

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 day

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross reject

Icterus

Mild OK; Gross OK

Other

NA

NY State Approved

Yes

Method Name

Enzyme Immunoassay (EIA)

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Gastroenterology and Hepatology Client Test Request (T728)

Secondary ID

8176