Anti-Smooth Muscle Antibody, Medical Tests, NE - CHI Health, Omaha
Back to MainBack to Main   Print This Page Print    Email to a Friend Email

Blood test
Blood test

Types of muscle tissue
Types of muscle tissue

Anti-smooth muscle antibody


Anti-smooth muscle antibody is a blood test that detects the presence of antibodies against smooth muscle. The antibody is useful in making a diagnosis of autoimmune hepatitis.

How the Test is Performed:

A blood sample is needed. This may be taken through a vein. The procedure is called a venipuncture .

How to Prepare for the Test:

No special steps are needed to prepare for this test.

How the Test will Feel:

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test is Performed:

You may need this test if you have signs of certain diseases, such as hepatitis and cirrhosis . These conditions can trigger the body to form antibodies against smooth muscle.

Normal Results:

Normally, there are no antibodies present.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean:

A positive test may be due to:

The test also helps distinguish autoimmune hepatitis from systemic lupus erythematosus .


Risks associated with having blood drawn are slight, but may include:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)


Czaja AJ. Autoimmune hepatitis. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, PA: Elsevier Saunders; 2010:chap 88.

Review Date: 1/20/2015
Reviewed By: Gordon A. Starkebaum, MD, Professor of Medicine, Division of Rheumatology, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.