Role of ANA and Myositis Autoantibodies in Diagnosis

The discovery of an increased repertoire of autoantibodies associated with idiopathic inflammatory myositis has important implications for enabling earlier diagnosis. Either a myositis-specific or a myositis-associated autoantibody is present in about 70% of adult and juvenile cases and in many cases identify specific patterns of disease and co-morbidities. In the future, it is likely that knowledge of a myositis autoantibody profile will be more fully incorporated into diagnostic and classification criteria and lessen the need for more invasive investigative procedures. In the meantime, there is a need for standardisation of commercial assays that are becoming more available, awareness of the reliability of initial autoantibody screening procedures, and guidance on how to interpret myositis autoantibody results in a given clinical context.