Anti-Mitochondrial Antibody Blood Test (AMA)

The Anti-Mitochondrial Antibody (AMA) blood test is used to detect autoantibodies directed against mitochondria, the energy-producing structures within cells. These antibodies are strongly associated with primary biliary cholangitis (PBC), a chronic autoimmune liver condition in which the small bile ducts within the liver are gradually damaged. This test is typically requested when a patient has unexplained abnormal liver function tests, particularly raised alkaline phosphatase (ALP), or symptoms such as persistent fatigue, itching (pruritus), dry eyes and mouth, or jaundice. It may also be used to investigate other autoimmune or cholestatic liver disorders and to help distinguish PBC from other forms of liver disease. A positive result does not confirm a diagnosis on its own; it is interpreted alongside clinical history, physical examination, and other liver investigations. The test requires a simple blood sample, which is collected by a trained phlebotomist.

Biomarkers
- Anti-Mitochondrial Antibody (AMA): Detects autoantibodies that target mitochondrial antigens. A positive result is a key serological marker for primary biliary cholangitis and can also be found in other autoimmune conditions, though it is most specific for PBC.

Why it matters
Early identification of AMA can prompt timely referral and specialist assessment, allowing for monitoring of liver function and management of primary biliary cholangitis before significant liver damage occurs. It provides valuable diagnostic clarity when other liver tests are abnormal and helps guide appropriate clinical follow-up.