Inflammatory Myopathies: Utility of Antibody Testing

Inflammatory myopathies are a group of immune-mediated muscle disorders comprising dermatomyositis; polymyositis; overlap myositis, including antisynthetase syndromes and nonspecific myositis, immune-mediated necrotizing myopathies, and sporadic inclusion body myositis. They are now much more eloquently classified both pathologically and clinically because of the discovery of several myositis-specific and myositis-associated antibodies. These antibodies also aid in choosing the best treatment options in each case. Based on the initial classifications of inflammatory myopathies, inclusion body myositis, overlap myositis, and necrotizing myositis were all included in the polymyositis group. This article discusses cases, diagnostic tools, associated antibodies, and pathology.