actin smooth muscle igg antibody test

Smooth muscle actin antibodies (SMA) are autoantibodies your immune system produces against smooth muscle tissue in your body. These antibodies are strongly associated with autoimmune hepatitis, a serious liver inflammation condition. Elevated SMA indicates your immune system is attacking liver cells. This test is typically ordered when liver enzyme abnormalities are detected. Positive results typically require treatment with immunosuppressive medications to prevent liver damage and cirrhosis.

This test detects IgG antibodies against smooth muscle actin, a protein found in smooth muscle tissue. Positive results suggest autoimmune liver disease, particularly autoimmune hepatitis. In this condition, the immune system mistakenly attacks the liver, causing inflammation and potential cirrhosis if untreated. This antibody is relatively specific for autoimmune hepatitis and helps distinguish it from other liver diseases. Early diagnosis is crucial because immunosuppressive therapy can effectively manage the condition and prevent liver damage.