THU0586 CLINICAL CHARACTERISTICS AND RISK FACTORS OF POLYMYOSITIS AND DERMATOMYOSITIS COMBINED WITH INTERSTITIAL LUNG DISEASE IN PATIENTS RESIDING IN THE NORTHEAST SICHUAN PROVINCE IN CHINA
Authors: Zi-Yi Tang, Yu-Feng Qing, Jian-Xiong Zheng, Dan Wang, Ting Yi, Wen-Jun Zhou, Qian Qin
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Idiopathic inflammatory myositis (IIM) is a systemic autoimmune disease characterized by nonsuppurative inflammation of striated muscle, myalgia, and proximal and symmetric muscle weakness. IIM can affect numerous organ systems, such as the skin, lungs, heart, and gastrointestinal tract. Polymyositis (PM) and dermatomyositis (DM) are the most common forms of IIM. Interstitial lung disease (ILD) is a common and severe complication of PM/DM, and concurrent ILD in patients with PM/DM is a major cause of death, with a fatality rate that exceeds 50%[1]. To explore the clinical features and risk factors of PM/DM combined with ILD (PM/DM-ILD)can improve the early diagnosis rate, put early interventions and improve the therapeutic effect. <h3>Objectives</h3> We explored the clinical features and risk factors of PM and DM, combined with ILD to increase early diagnosis and improve treatment outcomes. <h3>Methods</h3> Data were collected from 130 patients with PM/DM, treated at a single center from January 1, 2014 to September 30, 2018. General medical status, clinical symptoms, laboratory indicators, high-resolution computed tomography, therapeutic outcomes, and prognoses were retrospectively reviewed in patients with PM/DM with (ILD group) and without (NILD) ILD. <h3>Results</h3> There was statistically significant difference in age between the ILD group (n=65) and the NILD group (n=65) (<i>p</i><i>&lt;</i>0.05), but no significant between-group differences in PM/DM ratio, sex, or disease duration (<i>p</i>&gt;0.05 for all). In the ILD group, initial symptoms were arthritis and respiratory symptoms, and myasthenia for the NILD group. Incidences of Raynaud's phenomenon, dry cough, expectoration, dyspnea on exertion, arthritis, fever, globulin (GLOB), erythrocyte sedimentation rate (ESR), and anti-Jo-1 antibody rate were higher for ILD (<i>p</i>&gt;0.05 for all); however, albumin (ALB), creatine kinase aspartate aminotransferase activity ratio <b>(</b>CK/AST) and CK were significantly lower in the ILD group (<i>p</i>&gt;0.05 for all). Bivariate logistic regression analysis showed that age, dry cough, arthritis, dyspnea on exertion, anti-Jo-1 antibody, and elevated GLOB were independent risk factors for ILD among patients with PM/DM. <h3>Conclusion</h3> The morbidity associated with PM/DM-ILD is high. Older age, dry cough, arthritis, dyspnea on exertion, anti-Jo-1 antibody positivity, and increased GLOB increase the risk of developing ILD. This information could be used to carefully monitor changing lung function in these patients. <h3>References</h3> [1] Lega JC, Reynaud Q, Belot A, et al. (2015) Idiopathic inflammatory myopathies and the lung. Eur Respir Rev24(136):216-238. <h3>Disclosure of Interests</h3> Zi-Yi Tang: None declared, Yu-Feng Qing Grant/research support from: Sichuan Youth Science and Technology (2016JQ0053), and the Department of Science and Technology of Sichuan Province (2018JY0257), Jian-Xiong Zheng: None declared, Dan Wang: None declared, Ting Yi: None declared, Wen-Jun Zhou: None declared, Qian Qin: None declared