Test guide

Smooth Muscle Antibody (SMA) Test

This test looks for smooth muscle antibodies (SMAs) in a sample of your blood. High levels of SMAs are usually a sign of a chronic (long-lasting) liver condition called autoimmune hepatitis .

For everyone & professionalsReviewed 2026-10-18

What it is for

An SMA test is mainly used with other tests to help find out if autoimmune hepatitis could be the cause of liver damage. There are two types of autoimmune hepatitis. Each type involves different autoantibodies, So, an SMA can also help find out which type of autoimmune hepatitis a person may have: Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.

Limitations

Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.

Also known as

  • anti-smooth muscle antibody, ASMA, actin antibody, ACTA, F-actin antibody

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