Description
Actin (Smooth Muscle) Antibody (IgG) - Actin is the major antigen to which smooth muscle antibodies react in autoimmune hepatitis. F-Actin IGG antibodies are found in 52-85% of patients with Autoimmune Hepatitis (AIH) or chronic active hepatitis and in 22% of patients with Primary Biliary Cirrhosis (PBC). Anti-Actin antibodies have been reported in 3-18% of sera from normal healthy controls. This test checks for smooth muscle antibodies (SMAs) in the blood.A smooth muscle antibody (SMA) is a type of antibody which is also known as autoantibody. If SMAs are present in blood, it is likely that the person have autoimmune hepatitis in which the immune system attacks liver tissues.
Antibodies recognizing actin are the main component of smooth muscle antibodies associated with autoimmune liver disease. Actin antibodies are found in approximately 75% of patients with autoimmune hepatitis (AIH) type 1, approximately 65% of patients with autoimmune cholangitis, approximately 30% of patients with primary biliary cirrhosis, and approximately 2% of healthy people. High values are closely correlated with AIH type 1.
Reference Range(s)
<20 U Negative
=20 U Positive
