Antimitochondrial antibodies (AMAs) are the autoimmune response that occurs when the body turns against its own cells, tissues, and organs. When this happens, the immune system attacks the body as though it were an infection. AMAs attack the mitochondria.
The AMA test looks for autoimmune disorders affecting the mitochondria. It is most often used to detect an autoimmune condition known as primary biliary cholangitis (PBC). The mitochondria are the energy factory cells. They are critical to the normal functioning of all cells.
- Anti-Mitochondrial Antibody Test measures the amount of anti-mitochondrial antibody (AMA) in blood.
- Generally, no antibodies are present in normal individuals.
- The body produces certain proteins in blood, known as antibodies, to fight-off foreign invaders. Antibodies fight foreign invaders by creating immunity against the foreign microorganisms. In some individuals, the body starts producing antibodies against its own cells and tissues. Such antibodies are then termed as autoantibodies.
- Anti-mitochondrial antibodies are autoantibodies that act against the mitochondria, located inside the cell. The mitochondria are responsible for producing energy inside the cells. An AMA positive test, strongly suggest the presence of autoimmune diseases
- Primary biliary cholangitis (PBC) is one such autoimmune disease of the liver, in which AMA is positive in 95% of the cases. In PBC, the bile ducts inside the liver are affected. Bile ducts become inflamed and the occurrence of scars causes obstruction in the flow of bile, with progressive liver damage
- An AMA Test may also be positive with bile duct obstruction caused by other factors. These include primary and secondary sclerosing cholangitis
- AMA Test may be positive with other autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, scleroderma, thyroiditis, etc.
- Lower levels of AMA may also be detected in some other liver diseases/conditions.
- At present, a total of 9 subtypes of mitochondrial antigens are recognized. These are denoted as M1 to M9. Out of these subtypes, M2 type of AMA is particularly recognized and detected, in cases of primary biliary cholangitis.
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.
Information compiled from DoveMed website.