AUTHOR=Li Yuhui , Gao Xiaojuan , Li Yimin , Jia Xiaohui , Zhang Xuewu , Xu Yan , Gan Yuzhou , Li Shiming , Chen Renli , He Jing , Sun Xiaolin 

TITLE=Predictors and Mortality of Rapidly Progressive Interstitial Lung Disease in Patients With Idiopathic Inflammatory Myopathy: A Series of 474 Patients

JOURNAL=Frontiers in Medicine

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2020.00363

DOI=10.3389/fmed.2020.00363

ISSN=2296-858X

ABSTRACT=<p><bold>Objective:</bold> This study was conducted to identify the characteristics and prognosis of rapidly progressive interstitial lung disease (RP-ILD) in idiopathic inflammatory myopathy (IIM) and to assess the predictors for poor survival of RP-ILD in IIM.</p><p><bold>Methods:</bold> A total of 474 patients with IIM were enrolled retrospectively according to medical records from Peking University People's Hospital. Clinical and laboratory characteristics recorded at the diagnosis of patients with RP-ILD and chronic ILD (C-ILD) were compared. The Kaplan–Meier estimator and univariate and multivariate analyses were used for data analysis.</p><p><bold>Results:</bold> ILD was identified in 65% (308/474) of patients with IIM. Patients with ILD were classified into two groups based on lung features: RP-ILD (38%, 117/308) and C-ILD (62%, 191/308). RP-ILD resulted in significantly higher mortality in IIM compared with C-ILD (27.4 vs. 7.9%, <italic>P</italic> &lt; 0.05). In this study, by comparing IIM patients with and without RP-ILD, a list of initial predictors for RP-ILD development were identified, which included older age at onset, decreased peripheral lymphocytes, skin involvement (periungual erythema, skin ulceration, and subcutaneous/mediastinal emphysema), presence of anti-MDA5 antibody, serum tumor markers, etc. Further multivariate Cox proportional hazards model analysis identified that anti-MDA5 positivity was an independent risk factor for mortality due to RP-ILD (<italic>P</italic> &lt; 0.05), and lymphocytes &lt;30% in BALF might also be associated with poor survival of myositis-associated RP-ILD (<italic>P</italic> &lt; 0.05).</p><p><bold>Conclusion:</bold> Our study shows that RP-ILD results in increased mortality in IIM. Anti-MDA5 positivity and a lower lymphocyte ratio in BALF might be the predictive factor of mortality due to RP-ILD.</p>