[New autoantibodies in dermatomyositis]

Dermatomyositis is an idiopathic inflammatory myopathy that affects skeletal muscle and the skin. Idiopathic inflammatory myopathies are characterized by the production of autoantibodies directed against different cell structures. Some of these autoantibodies are specific to idiopathic inflammatory myopathies (myositis-specific antibodies) whereas others are found in a range of overlap syndromes (myositis-associated antibodies). Although they are all associated with certain clinical and physiopathological characteristics of myositis, myositis-specific antibodies are essentially the most useful markers for clinical diagnosis, classification, and prognosis in idiopathic inflammatory myopathies. In recent years, two new myositis-specific antibodies in clinically amyopathic dermatomyositis (CADM), CADM-140 and, in cancer-associated dermatomyositis, anti-p155/p140 have been identified. This is of great importance as no myositis-specific antibodies had previously been detected in these clinical subgroups. The identification of target antigens that are recognized by these antibodies is essential for a better understanding of the pathogenesis of these diseases.