What is a smooth muscle antibody (SMA) test?This test looks for smooth muscle antibodies (SMAs) in the blood. A smooth muscle antibody (SMA) is a type of antibody known as an autoantibody. Normally, your immune system makes antibodies to attack foreign substances like viruses and bacteria. An autoantibody attacks the body's own cells and tissues by mistake. SMAs attack smooth muscle tissues in the liver and other parts of the body.If SMAs are found in your blood, it is likely you have autoimmune hepatitis. Autoimmune hepatitis is a disease in which the immune system attacks liver tissues. There are two types of autoimmune hepatitis:Type 1, the most common form of the disease. Type 1 affects more women than men. It is also more common in people who also have another autoimmune disorder.Type 2, a less common form of the disease. Type 2 mostly affects girls between the ages of 2 and 14.Autoimmune hepatitis can be managed with medicines that suppress the immune system. Treatment is more effective when the disorder is found early. Without treatment, autoimmune hepatitis can cause serious health problems, including cirrhosis and liver failure.Other names: anti-smooth muscle antibody, ASMA, actin antibody, ACTA
