Myositis specific autoantibodies.

Recent studies have continued to examine the clinical associations of the group of autoantibodies that occurs predominantly in patients who have myositis (antibodies to aminoacyl-tRNA synthetases, to signal recognition particle [SRP], and to the nuclear helicase Mi-2). The anti-synthetase syndrome has been further studied, and the value of tacrolimus in treatment of the associated interstitial lung disease has been noted. The low frequency of myositis specific autoantibodies in non-myositis neuromuscular disorders has been more clearly demonstrated. The clinical associations of anti-Mi-2 and anti-SRP were further studied, and patients with antibodies without myositis were reported. Evidence suggested that ultraviolet light exposure may influence the expression of dermatomyositis and anti-Mi-2. A new classification for myositis using overlap clinical features and autoantibodies was proposed. A new autoantibody, anti-caDM-140, was described, associated with clinically amyopathic dermatomyositis and interstitial lung disease. The possibility was raised that increased antigen expression in regenerating muscle may help to perpetuate the disease. These antibodies continue to be the subject of active investigation.