AB0699 DESCRIPTIVE STUDY OF A COHORT OF PATIENTS WITH DERMATOMYOSITIS IN A TERTIARY HOSPITAL.

Abstract

BackgroundIdiopathic chronic inflammatory myopathies (IICM) are a heterogeneous group of rare diseases characterized by skeletal muscle inflammation. The incidence ranges from 1 to 60 new cases per 1,000,000 habitants/year and the prevalence between 2.4 and 34 per 100,000 habitants.The main symptoms are muscle weakness, which may be accompanied by contractures, pain, cramps or stiffness and symptoms related to localized disease in skin, lungs and other organs. Increased muscle enzymes and a myopathic pattern are seen on electromyography. Definitive diagnosis is made by muscle biopsy with lymphocyte infiltrates, necrosis and regeneration of muscle fibers.ObjectivesDescription of the clinical characteristics of a cohort of patients diagnosed with dermatomyositis together with the study of the evolution: organic involvement, specific autoantibody profile and treatments performed in this population.MethodsDescriptive study of a cohort of patients diagnosed with dermatomyositis at the Rocio Virgin University Hospital (Seville), during 2010-2022, obtained from medical records.ResultsSixty patients were included, including 17 (28.3%), 43 (71.7%) women, whose mean age 58 +/-12 years, and mean time of diagnosis was 5 years. Among the types of inflammatory myopathies: dermatomyositis 37 (61.6%), amyopathic DM 6 (10%), antisynthetase syndrome 5 (8.3%), paraneoplastic 1 (1.6%) and rapidly progressive MDA5 7 (11.6%) Among the most frequent affections: pulmonary 20 (34%) being the most frequent NINE pattern 9 (45%), NIU 8 (40%); esophageal 20 (34%), cardiological 12 (20%).Among the specific antibodies: ANA positive 24(40%), Ro 3(5%), La4(6.6%),JO1 6(10%),PL7 1(1.6%)PL12 1(1.6%),Mi2 1(,1.6%),SAE 3(5%),NXP2 2(3.3%),SRP 1(1.6%),MDA5 7(11.6%) and HMG-CoA 3(5%). Among the diagnostic tests MRI/electromyogram were positive 63% and 56.6% respectively. Biopsy was positive in 72%(42) of cases. The drugs used to induce remission were: cyclophosphamide 36 (60%), rituximab 12 (20%), immunoglobulins 6 (10%) and mycophenolate mofetil 6 (10%). As for the maintenance of remission: mycophenolate 54 (90%), methotrexate 3 (5%) and azathioprine 3 (5%). There was only one exitus caused by cardiac arrhythmia.ConclusionThe results obtained have been in accordance with the published literature, with a clear association between specific autoantibodies and the different muscular and extramuscular manifestations. Among the remission inducers, the most frequent regimen used in our setting is the use of cyclophosphosmide/ rituximab and maintenance of remission with azathioprine and mycophenonate. More studies on new therapeutic options are needed.Disclosure of InterestsNone declared