AB0445\u2005FIRST CLINICAL ANALYSIS OF MYOSITIS PATIENTS REGISTERED AT REUMA.PT/MYOSITIS PROTOCOL: DATA FROM A SINGLE-CENTER

Abstract

Idiopathic inflammatory myopathies are a group of rare heterogeneous diseases that require a multidisciplinary and standardized approach.To clinically characterize patients with inflammatory myopathies followed at an hospital’s Rheumatology Department, using the Rheumatic Diseases Portuguese Register (Reuma.pt).An observational transversal study was performed. Data on demographic variables, clinical features, antibodies and treatment were collected.Of the 121 included patients, 78% were female, with a median age of 56 [44-68] years and a median disease duration of 2 [0-4] years. The most frequent diagnosis was dermatomyositis (DM; n=28, 23%) followed by antisynthetase syndrome (ASyS; n=21, 17.4%). At the time of the analysis, the median Manual Muscle Test (MMT-8) was 80 [78-80], the median modified skin Disease Activity Score was 0 [0-2] and global disease activity was 0.5 [0-0.75]. Calcinosis was found in 6% of the patients (n=7), mostly DM cases. Interstitial lung disease (ILD) was present in 29 patients (24%), of those, 52% (n=15) had antisynthetase syndrome (ASyS). Three patients presented as a paraneoplastic syndrome. Ninety-nine patients (82%) had a myositis autoantibody identified: antisynthetase autoantibodies were the most commonly identified (n=20, 16%). 62% of the patients were treated with steroids and 35% with ≥2 disease-modifying anti-rheumatic drugs.Table 1 depicts the main clinical characteristics and the immunologic profile for each diagnosisIn our cohort the most frequent myositis subtype was DM. Almost a quarter of patients had associated ILD, which is an important cause of morbidity and mortality. ILD was more frequent in ASyS patients and was most commonly related to anti-Jo1 antibodies, which is consistent with the literature.Table 1.Clinical characteristics and immunological profile of the patients.Diagnosis (n)Clinical featuresMyositis antibodies (n)Skin disease, median [IQR]/ (n)MMT-8, median [IQR]Lung disease (n)Others (n)Malignancy (n)Definite DM (28)DAS Skin 2 [0-2]Calcinosis (3)Mechanic hands (2)80 [75-80]NSIP (2);COP (1)Arthritis (6)Breast cancer (1)anti-Ro52 (6); anti-Mi2b (5); anti-PmScl100 (4); anti-MI2a (3); anti-NXP2 (3); anti-SAE (2); anti-MDA5 (2); anti-Ku (2); anti-Tif1g (1)Antisynthetase syndrome (21)DAS Skin 0 [0-0]Calcinosis (1)Mechanic hands (4)80 [80-80]NSIP (11);UIP (3);LIP (1)Arthritis (15);RP (10)–anti-Jo1 (14); anti-Ro52 (12); anti-Mi2b (1); anti-PL7 (3); anti-PL12 (1)Probable DM (19)DAS Skin 0 [0-0]80 [78-80]COP (1)Arthritis (5);RP (6)–anti-Mi2a (4); anti-Mi2b (2); anti-Tif1g (2); anti-Ku (2); anti-PmScl75 (2)CADM (16)DAS Skin 1 [0-2]Calcinosis (1)Mechanic hands (1)80 [77-80]NSIP (1); COP (1)Arthritis (5);RP (4)–anti-Mi2b (5); anti-Ro52 (2); anti-Mi2a (1); anti-MDA5 (1); anti-EJ (1); anti-SAE (1); anti-SRP (1); anti-Ku (1); anti-Tif1g (1)MCTD (12)DAS Skin 0 [0-1]80 [79-80]NSIP (1)Arthritis (8);RP (10)–anti-U1 RNP (12); anti-Ro52 (7)PM (7)DAS Skin 0 [0-0]Calcinosis (1)80 [72-80]NSIP (1)Arthritis (1)Ovarian cancer (1); non-Hodgkin lymphoma (1)anti-Ro52 (2); anti-SRP (1)UCTD (5)DAS Skin 0 [0-2]Calcinosis (1)Mechanic hands (1)80 [79-80]NSIP (2)Arthritis (1);RP (5)–anti-ThTo (2); anti-SRP (1); anti-PL12 (1)Overlap syndromes (12)DAS Skin 0 [0-2]Mechanic hands (2)80 [77-80]NSIP (3);UIP (1)Arthritis (4);RP (8)–anti-PmScl75 (4); anti-PmScl100 (1); anti-Ro52 (1); anti-Ro60 (1); anti-RNAPIII (1); anti-NOR90 (1); anti-MDA5 (1); anti-Ku (1)Necrotizing myopathy (1)DAS Skin 080––––DM – dermatomyositis; CADM – clinically amyopathic dermatomyositis; MCTD – mixed connective tissue disease; PM – polymyositis; UCTD – undifferentiated connective tissue disease; ILD – interstitial lung disease; NSIP – nonspecific interstitial pneumonia; LIP – lymphocytic interstitial pneumonitis; UIP – usual interstitial pneumonia; COP – cryptogenic organizing pneumonia; RP – Raynaud phenomenonNone declared.