[Antisynthetase Syndrome-Associated Myositis]

Antisynthetase syndrome-associated myositis is a major form of autoimmune myositis defined by the presence of anti-aminoacyl tRNA synthetase autoantibodies. It involves the skeletal muscle as well as the lungs, joints, and skin. Severity of each symptom varies by autoantibody subtype; anti-OJ is associated with severe muscle involvement. Pathological changes from the perimysium to the adjacent perifascicular area, including perifascicular necrosis, is a distinctive feature. The skeletal muscle provides an immunological micro-milieu for specific plasma cells. Therapies against plasma cells or factors defining B cell/plasma cell niche may be a more effective mechanism-specific treatment.