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Also known as: Mitochondrial antibody
Formal name: Antimitochondrial antibody; antimitochondrial M2 antibody

At a Glance

Why Get Tested?

To help diagnose primary biliary cirrhosis (PBC)

When to Get Tested?

When a doctor suspects that a patient may have PBC

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?


The Test Sample

What is being tested?

This test measures the amount of antimitochondrial antibodies (AMA) in the blood. The production of AMA is strongly associated with primary biliary cirrhosis (PBC). PBC is an autoimmune disorder that causes inflammation and scarring of the bile ducts inside the liver. It is found most frequently in women between the ages of 35 and 60. PBC blocks the flow of bile and causes progressive liver damage. About 90% of those affected by PBC will have significant concentrations of antimitochondrial antibodies.

There are several types of AMA designated as M1, M2, M3, M5, and M6. The M2 type has been found to be the most strongly associated with PBC, while the others may also be found in other conditions. Some laboratories have started to offer both AMA-M2 and AMA, as well as other rarer antibodies associated with PBC.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.