Anti-smooth muscle antibody

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

No special steps are needed to prepare for this test.

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

You may need this test if you have signs of certain liver diseases, such as hepatitis and cirrhosis . These conditions can trigger the body to form antibodies against smooth muscle. Anti-smooth muscle antibodies are not often seen in diseases other than autoimmune hepatitis. Therefore, it is helpful to make the…

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.

A positive test may be due to: Chronic active autoimmune hepatitis Cirrhosis Infectious mononucleosis 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 and Fordtran's Gastrointestinal and Liver Disease . 11th ed. Philadelphia, PA: Elsevier; 2021:chap 90. Ferri FF. Laboratory values and interpretation of results. In: Ferri FF, ed. Ferri's Best Test: A Practical Guide to Clinical…