Smooth Muscle Antibodies

Serum smooth muscle antibodies (SMA) react with different components of the cytoskeletal network (actin, tubulin, vimentin, desmin, cytokeratins). Their presence characterizes both autoimmune (autoimmune hepatitis, coeliac disease) and viral diseases (chronic hepatitis C, infectious mononucleosis). When detected at titers higher than 1:80, they are considered a sensitive marker for type 1 autoimmune hepatitis (AIH-1), being found in up to 80% of cases