Actin (Smooth Muscle) Antibody (ASMA)

CPT: 83516
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Test Details


  • Antiactin
  • Smooth Muscle Antibodies


Detection of antibodies aids in the diagnosis of autoimmune liver diseases such as autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC)


Antiactin antibodies have been reported at low levels in 3% to 18% of sera from the general healthy population. The presence of immune complexes in the patient's sample may produce false positives in this assay. Not all smooth muscle positive samples will have actin antibodies.


Enzyme-linked immunosorbent assay (ELISA)

Reference Interval

• Negative: 0−19

• Weak positive: 20−30

• Moderate to strong positive: >30

Additional Information

Actin antibodies are found in 52% to 85% of patients with autoimmune hepatitis or chronic active hepatitis and in 22% of patients with primary biliary cirrhosis.

Specimen Requirements




1 mL

Minimum Volume

0.3 mL


Red-top tube or gel-barrier tube

Storage Instructions

Room temperature

Stability Requirements



Room temperature

14 days


14 days


14 days

Freeze/thaw cycles

Stable x3

Causes for Rejection

Hemolysis; lipemia; gross bacterial contamination; heat-treated specimen; specimen with preservative added


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
006643 Actin (Smooth Muscle) Antibody 34661-9 006644 Actin (Smooth Muscle) Antibody Units 34661-9

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