Idiopathic Inflammatory Myopathies (MII) are a heterogeneous group of diseases characterized by muscle weakness and inflammation underlying muscle biopsy.
The main organs affected are muscle, skin and the lung can also be affected. They are distinguished within clinical subtypes such as Polymyositis (PM), Dermatomyositis (DM), DM with the variant Clinically Amiopathic Dermatomyositis (DMCA), the Syndrome Antisynthetase (SAS), Immune-mediated Necrotizing Myositis, Body Myositis Inclusion (MCI) and Neoplasia-Associated Myositis. The presence of certain specific and associated antibodies predisposes to the development of clinical manifestations, determining the disease prognosis. 4 patients from the Registry of MII of the Argentine Society of Rheumatology (SAR) are presented with these characteristics: one patient with PM and anti Jo-1 positive and three patients with DM (one with DMCA and anti-RO 52 and two patients with anti-PL7 and anti-TI-F1γ respectively).