ACTIN (Smooth Muscle) Antibody (IgG) [15043]

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Test Code

Alias/See Also
Anti Smooth Muscle

CPT Codes

Preferred Specimen
1 mL serum (minimum 0.5 mL) 

SST or Red top: Avoid hemolysis. Invert a minimum of 5 times, then allow to clot in an upright position for 30 minutes. Centrifuge the the tube for at least 10 minutes. Keep tightly stoppered.

Transport Container
SST (speckled top), Red top , Plastic Vial (transfer) tube

Transport Temperature
Room Temperature or Refrigerated (preferred)

Specimen Stability
Room Temperature = 24 hours
Refrigerated = 7 days
Frozen = at least 7 days


Setup Schedule
Monday - Wednesday - Friday

Report Available
3 days

Reference Range
SEX AGE Report Normals
N/M/F 1000Y < 20 = Negative
    20 - 30 = Weak Positive
    > 30 = High Positive
Anti-smooth muscle antibodies (ANTI-SMA) were previously tested for by indirect immunofluorescence (IF) using rat stomach as antigen.  To enhance our testing specificity for autoimmune hepatitis type 1 (AIH TYPE 1), immunofluorescence has been replaced by an ELISA based assay to purify F-ACTIN.  IgG antibodies to F-ACTIN are present in approximately 75% of patients with AIH TYPE 1, approximately 65% of patients with autoimmune Cholagitis, approximately 30% of patients with primary Biliary Cirrhosis, and approximatley 2% of healthy controls.  High values are closely correlated with AIH TYPE 1. 

Clinical Significance
The presence of actin antibodies can be used in conjunction with clinical findings and other laboratory tests to aid in the diagnosis of autoimmmune liver diseases such as autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC).

Performing Laboratory
Compunet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine, OH 45439

Last Updated: January 19, 2022

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.