Anti-smooth muscle antibody

Normal values:

No presence of antibodies is normal.

What abnormal results mean:

Up to 90% of people with chronic active hepatitis, and 25 to 40% of those with biliary cirrhosis and idiopathic cirrhosis, are positive for this test (compared to less than 5% of normal people). Anti-smooth muscle antibodies are also commonly present in infectious mononucleosis and some malignant (growing worse and resisting treatment) tumors. Anti-smooth muscle antibody tests also help distinguish lupoid hepatitis from systemic lupus erythematosus.