Clinical characteristics of dermatomyosits/polymyositis associated interstitial lung disease according to the autoantibody.

Abstract

Dermatomyositis (DM) and polymyositis (PM) often have association with interstitial lung disease (ILD) which have disease specific autoantibody. We reviewed medical records of DM/PM associated ILD from January 2000 to December 2017 according to the autoantibody. We identified 52 patients, of whom 30 were antibody negative, 18 had anti aminoacyl-tRNA synthetases (ARS) antibodies and 4 had anti melanoma differentiation-associated gene (MDA)-5 antibody. In high resolution computed tomography (HRCT) of the chest, area of ground glass opacity (GGO), consolidation, and lung tip consolidation were more extensive in anti MDA-5 antibody positive patients (p=0.051, p=0.026, and p=0.027, respectively). Among laboratory findings, GOT had strong correlations with CPK (r=0.889, p < 0.001), and LDH (r=0.910, p < 0.001). Among roentgenographic findings, there were moderate correlations between GGO and consolidation (r=0.668, p < 0.001), and between reticular shadow and traction bronchiectasis (p=0.633, p < 0.001). ILD patients with anti MDA-5 antibodies had decreased survival (1.00 vs 84.3, 22.9 months, p < 0.001). ILD patients with anti ARS antibody had intense inflammation, but reversible fibrosis and good prognosis. On the other hand, anti MDA-5 antibody positive ILD patients had shorter survival. Extent of parenchymal shadow and serum GOT were useful indicator of disease activity of PM/DM associated ILD patients in our cohort. J. Med. Invest. 65:251-257, August, 2018.