Smooth muscle actin is a type of protein found in smooth muscles and other tissues like liver. Smooth muscle antibodies (SMA) are autoantibodies, proteins produced by the body’s immune system that recognize and attack its own actin.
What is smooth muscle actin test?
It is a blood test that detects the presence of antibodies against the patient’s smooth muscles.The test is associated with autoimmune hepatitis. Majority of smooth muscle antibodies produced due to autoimmune hepatitis is specifically directed against a protein called or F-actin. Autoimmune hepatitis can affect anyone at any age; however 80% of the patients being women.
Why is smooth muscle actin test suggested?
The test focuses on diagnosing autoimmune hepatitis and distinguish it from any other liver disease. The test is needed if there are signs of cirrhosis or hepatitis as these conditions trigger the body to form antibodies against smooth muscles.
How is smooth muscle actin test performed?
The test requires a blood sample drawn from a vein in thee arm.
What are the parameters measured in the test?
The test focuses on the presence of smooth muscles antibodies in the sample collected.
Preparation before performing smooth muscle actin test.
No special preparatory steps are needed for the test.
Post care after smooth muscle actin test
Care needs to be taken depending on the antibodies’ range as normal value ranges from laboratory to laboratory.
Sample types in smooth muscle actin test.
The test results may either be positive or negative.
A positive result may be due to-
- Chronic active immune hepatitis
- Infectious mononucleosis
Side effects/risks of smooth muscle actin test.
No specific risks/side effects. There might be chances of blood clotting or excessive bleeding from the area from where blood sample is collected.