Prognostic factors for myositis-associated interstitial lung disease.

Tomoyuki Fujisawa,Toshihiro Shirai,Mikio Toyoshima,Koshi Yokomura,Noriyuki Enomoto,Yutaro Nakamura,Hironao Hozumi,Kazumasa Yasuda,Naoki Koshimizu,Naoki Inui,Takafumi Suda,Masato Kono,Dai Hashimoto,Hiroshi Hayakawa

doi:10.1371/journal.pone.0098824

Abstract

BackgroundInterstitial lung disease (ILD) is a common manifestation of polymyositis (PM), dermatomyositis (DM), and clinically amyopathic dermatomyositis (CADM); however, little is known about the factors influencing the prognosis for PM/DM/CADM-associated ILD. (PM/DM/CADM-ILD). The aim of the present study is to assess prognostic factors for PM/DM/CADM-ILD.MethodsThe clinical features and survival of 114 consecutive patients diagnosed with PM/DM/CADM-ILD (39 men and 75 women; median age, 56 years) were analyzed retrospectively.ResultsThe study group included 30 PM-associated ILD, 41 DM-associated ILD, and 43 CADM-associated ILD cases. The clinical presentation of ILD was acute/subacute form in 59 patients (51.8%) and chronic form in 55 patients (48.2%). The major pulmonary symptoms were dyspnea, cough, and fever. High-resolution computed tomography frequently revealed ground-glass opacities, traction bronchiectasis, and consolidation. Most of the patients were treated with corticosteroids or corticosteroids in combination with immunosuppressive agents. The all-cause mortality was 27.2%. Acute/subacute form, % forced vital capacity (FVC), age, % of neutrophils in bronchoalveolar lavage (BAL) fluid, and a diagnosis of CADM (vs. PM) were significantly associated with poor outcome in univariate Cox proportional hazards models. Multivariate Cox proportional hazards analysis validated acute/subacute ILD, %FVC, age, and diagnosis of CADM (vs. PM) as significant predictors of overall mortality. Patients with acute/subacute ILD had a much lower survival rate than those with the chronic form (p<0.001). Patients with CADM-ILD had a lower survival rate than those with PM-ILD (p = 0.034).ConclusionsAcute/subacute form, older age, lower level of FVC and diagnosis of CADM predict poor outcome in PM/DM/CADM-ILD.

Highlights

The idiopathic inflammatory myopathies (IIMs) are a group of systemic inflammatory diseases that affect skeletal muscles and result in proximal muscle weakness, elevated muscle enzyme levels and extramuscular manifestations such as fever, weight loss and rash [1]
We have previously reported that DMassociated Interstitial lung disease (ILD) (DM-ILD) is more refractory to corticosteroid therapy and carries a poorer prognosis than PM-associated ILD (PM-ILD) [6]
The frequency of the acute/ subacute form was almost identical among patients with PM-ILD, DM-ILD, and clinically amyopathic dermatomyositis (CADM)-ILD (46.7%, 53.7%, and 53.5%, respectively)

Summary

Introduction

The idiopathic inflammatory myopathies (IIMs) are a group of systemic inflammatory diseases that affect skeletal muscles and result in proximal muscle weakness, elevated muscle enzyme levels and extramuscular manifestations such as fever, weight loss and rash [1]. Polymyositis (PM) and dermatomyositis (DM) are two major diseases affecting the muscles, skin, and other organs, including the lungs, in patients with IIMs [1,2]. Amyopathic dematomyositis (CADM) is a distinct subgroup of DM that causes the typical skin rash of classic DM with little or no evidence of muscular manifestations [3,4]. Recent studies have revealed that interstitial lung disease (ILD) to be a crucial extramuscular manifestation of PM, DM and CAMD patients that is associated with high mortality [5,6,7,8]. Interstitial lung disease (ILD) is a common manifestation of polymyositis (PM), dermatomyositis (DM), and clinically amyopathic dermatomyositis (CADM); little is known about the factors influencing the prognosis for PM/ DM/CADM-associated ILD. The aim of the present study is to assess prognostic factors for PM/DM/ CADM-ILD

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