Description
Anti-Smooth Muscle Antibodies (ASMA) are autoantibodies—proteins produced by the immune system that incorrectly target the body’s own smooth muscle and other cell types. The presence of high levels of ASMA in the blood is a strong indicator of an autoimmune process affecting the liver.
Clinical Significance:
- Autoimmune Hepatitis (AIH): The primary use of the ASMA test is to help diagnose Type 1 Autoimmune Hepatitis. About 70-80% of patients with AIH Type 1 will have a positive ASMA test. It is often ordered along with an ANA (Anti-Nuclear Antibody) test.
- Other Conditions: Low levels of ASMA can sometimes be seen in other conditions, such as primary biliary cholangitis (PBC), viral hepatitis (Hepatitis B or C), or certain cancers, which is why it’s interpreted within the full clinical context.
When is this test recommended?
- To investigate the cause of chronic liver disease, especially when viral hepatitis and other common causes have been ruled out.
- When a patient has unexplained elevated liver enzymes (ALT, AST) and symptoms of liver dysfunction like fatigue, jaundice, or abdominal pain.
- To differentiate autoimmune hepatitis from other types of liver disease.
Sample Requirements:
- Specimen: Serum.
- Container: Gold Top (SST) or Red Top Tube.
- Preparation: No fasting is typically required.
