AB0607 MYOSITIS-RELATED INTERSTITIAL LUNG DISEASES: CLINICAL FEATURES, BIOMARKERS AND AUTOANTIBODIES IN LATINOAMERICAN PATIENTS

Abstract

Background:The lung is one of the most common extra-muscular targets in idiopathic inflammatory myopathies (IIM) and interstitial lung disease (ILD) is a prevalent and often devastating manifestation of IIM1.Objectives:To know the frequency of autoantibodies associated with IMM-ILD, biomarkers, and their relation with clinical features in patients with IIM.Methods:Adults with IIM were enrolled in a retrospective way. Demographics, clinical and laboratory features were registered. The determination of antibodies was perfomed by the Inmunoblot technique with Euroinmmun kit. Patients without a myositis antibody panel were excluded. The diagnosis of ILD was based on HRCT. Patients with anti-MDA5 antibodies and with anti Ro-52 antibodies associated with anti-ARS were considered as high risk group, those with anti-ARS, anti-U1-RNP, anti-PM/ Scl and anti-Ku antibodies as moderate risk and those with anti-Mi2, anti SRP and anti TIF1 antibodies as low risk2.Results:Demographics characteristics are shown in table 1. We included 36 patients. Dermatomyositis (DM) was described in 69.4%, polymyositis (PM) in 16.7% and antysnthetase syndrome (AAS) in 13.9%. Out of the total of our patients, 30.6% had interstitial lung disease. The most frequent autoantibody was Anti Ro52 in 13 (36.1%) patients and 44.4% were in the high risk group. We analized our patients by the presence or absence of ILD and we found that anti-MDA5 antibodies were more frequent in IMM-ILD group (p=0.006). In our IMM-ILD group we compared the autoantibodies with the clinical and serological features and we found that patients with IMM- ILD and anti Ro-52 antibody had more frequency of heliotrope rash (p=0.045) and those with IMM- ILD and anti-Jo1 antibody had a higher level of CK (p<0.001).Table 1.Demographic characteristicsAge, mean SD40.611 +/- 16.37Women, n(%)24 (66.7%)Diagnosis Dermatomiositis25 (69.4%) Polimiositis6 (16.7%) Síndrome antisintetasa5 (13.9%)Time of evolution *6.00 (2.25 – 19.00)Interstitial lung disease11 (30.6%)Serological CK305.00(50.75 – 1969.250) LDH460.727 +/- 384.76Risk ILD complicated with IIM High16 (44.4%) Moderate8 (22.2%) Low12 (33.3%)*monthsTable 2.Clinical and serological comparation between IMM groups with and without ILDIMM with ILD, n=11IMM without ILD, n=25pProximal muscle weakness10 (90.9%)22 (88.0%)NSHeliotrope Rash7 (63.6%)10 (40.0%)NSMechanic hands4 (36.4%)4 (16.0%)NSAnti-Mi-22 (18.2%)8 (32.0%)NSAnti-Tif1 γ0 (0.0%)6 (24.0%)NSAnti-MDA54 (36.4%)0 (0.0%).006Anti-NXP21 (9.1%)0 (0.0%)NSAnti-SAE10 (0.0%)1 (4.0%)NSAnti-Ku0 (0.0%)2 (8.0%)NSAnti-PM/Scl1000 (0.0%)1 (4.0%)NSAnti-PM/Scl752 (18.2%)0 (0.0%)NSAnti-Jo11 (9.1%)0 (0.0%)NSAnti-SRP0 (0.0%)3 (12.0%)NSAnti- PL120 (0%)1 (4.0%)NSAnti-EJ1 (0.1%)1 (4.0%)NSAnti- PL71 (9.1%)4 (16.0%)NSAnti-OJ0 (0.0%)2 (8.0%)NSAnti-Ro525 (45.5%)8 (32.0%)NSConclusion:Anti-MDA5 antibodies were more frequent in our IMM-ILD group than in IMM without ILD group. Almost half of our patients were in a high risk group, which means they need an early immunosuppressive treatment. In our IMM-ILD patients we found an association between the presence of anti Ro-52 antibody with heliotrope rash and of anti-Jo1 antibody to a higher level of CK.