Antimitochondrial antibody
Antimitochondrial antibodies (AMA) are substances (antibodies) that form against mitochondria, an important part of cells. Mitochondria are the energy source inside all of the body's cells. Mitochondria help cells work properly.
This article discusses the blood test used to measure the amount of AMA in the blood.
How the Test is Performed
A blood sample is needed. It is usually taken from a vein. The procedure is called a venipuncture.
How to Prepare for the Test
Your health care provider may tell you not to eat or drink anything for up to 6 hours before the test (usually overnight).
How the Test Will Feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
Your doctor may order this test if you have signs of liver damage. This test is most often used to diagnose primary biliary cirrhosis (PBC).
The test may also be used to tell the difference between bile system-related cirrhosis and liver problems due to a blockage, viral hepatitis, or alcoholic cirrhosis.
Normal Results
Normally, there are no antibodies present.
What Abnormal Results Mean
This test is important for diagnosing primary biliary cirrhosis. Up to 94% of patients with this condition are positive for this test. Less than 1% of people without the condition test positive.
Abnormal results may also be found, less often, in people with other kinds of liver disease and some autoimmune diseases.
Risks
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Update Date: 2/11/2013
Updated by: Ariel D. Teitel, MD, MBA, Clinical Associate Professor of Medicine, NYU Langone Medical Center. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2013, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.
