AB0565 EXPERIENCE IN THE USUAL PRACTICE OF PATIENTS WITH INFLAMMATORY MYOPATHIES AT THE DONOSTIA UNIVERSITY HOSPITAL

Background: Inflammatory myopathies (IM) are a heterogeneous group of acquired diseases, characterized by the presence of muscle weakness and inflammation. This group includes idiopathic polymyositis (PM), idiopathic dermatomyositis (DM), PM/DM associated with neoplasia, associated with rheumatic autoimmune diseases, juvenile PM/DM, inclusion body myositis (MCI) and immunomediated necrotizing myopathies (IMNM). Objectives: Inflammatory myopathies (IM) are a heterogeneous group of acquired diseases, characterized by the presence of muscle weakness and inflammation. This group includes idiopathic polymyositis (PM), idiopathic dermatomyositis (DM), PM/DM associated with neoplasia, associated with rheumatic autoimmune diseases, juvenile PM/DM, inclusion body myositis (MCI) and immunomediated necrotizing myopathies (IMNM). Methods: A retrospective search of all patients assessed in the service diagnosed with IM was performed. The computerized medical records were reviewed. The variables collected were: sex, age, underlying disease and immunosuppressive and biological treatments used, antibodies, and complementary tests. The immunosuppressant sought were methotrexate (MTX), azathioprine (AZA), hydroxychloroquine (HCQ), tacrolimus, mycophenolate (MMF), cyclophosphamide (CFM), cyclosporine (CsA), chloroquine; intravenous immunoglobulins (IVIG), rituximab (RTX). The quantitative variables are shown with the median and interquartile range; the qualitative ones are shown with the absolute value and its percentage Results: 42 patients were found diagnosed with IM; the average age of diagnosis was 54 years, with a predominance of women with 71.4%. Table 1 shows the clinical characteristics, complementary tests and treatments used in these patients. The registered deaths were 8 (19%); of which 6 (75%) were related to their cancer, one patient with IM with pulmonary involvement died in the context of a respiratory infection at 91 years of age, and the other patient in the context of a bowel obstruction with 87 years of age. Two (4.7%) patients presented an overlap syndrome, one with scleroderma and the other with systemic lupus erythematosus. The median CPK was higher at the time of diagnosis in patients in the IM group with pulmonary involvement. We also observed a greater involvement of the swallowing muscles, 7 (16%) in patients with IM associated with malignancy, and those who were more associated in the initial IVIG treatment, 9 (21%). The mean follow-up time of these patients is 94 months. The most widely used immunosuppressant drug was MTX 76%; followed by 50% IVIG and 38% AZA; among those who maintain current treatment the most used is MTX 28% second of RTX 17%. Conclusion: Despite the fact that IM are a serious disease, more than 80% of patients continue to follow up, IM presented more aggressively in IM patients associated with malignancy, and presented less aggressively in patients diagnosed at the juvenile age. In 40% of the patients, no specific antibody was found; possibly due to the fact that most of these patients were diagnosed more than 7 years ago, where the antibody pool was much more restricted than today’s Disclosure of Interests: Jesus Alejandro Valero Jaimes: None declared, Andrea De Diego Sola: None declared, Cesar Antonio Egues Dubuc Speakers bureau: Lilly pharma, Luis Maria Lopez Dominguez: None declared, Olga Maiz-Alonso Speakers bureau: Pfizer, Esther Uriarte Isacelaya: None declared, Jorge Jesus Cancio Fanlo Speakers bureau: janssen pharma, Joaquin Maria Belzunegui Otano: None declared