Comparison of characteristics of connective tissue disease-associated interstitial lung diseases and idiopathic pulmonary fibrosis

Abstract

Objective To compare the characteristics of connective tissue disease-associated interstitial lung disease (CTD-ILD) and idiopathic pulmonary fibrosis(IPF). Methods Patients with a diagnosis of ILD from June 2014 to December 2015 were selected in this study and patients with known other causes of ILD were excluded. The clinical manifestation, autoantibody, high resolution chest computed tomography (CT) and blood gas analysis were retrospectively analyzed. Results Six hundred and twenty-eight patients were included in this study. The prevalence of CTD-ILD and IPF were 459 (73.09%) and 169(26.91%) respectively. The age in IPF group was higher than that in CTD-ILD group: (67.10 ± 13.13) years vs. (52.10 ± 14.23) years, and there was significant difference (t = -10.092, P = 0.000). The rate of male in IPF group was higher than that in CTD-ILD group: 75.15% (127/169) vs. 28.32%(130/459), and there was significant difference (P = 0.000). Autoantibodies were commonly seen in CTD-ILD group and only antinuclear antibody, and anti-SSA antibody and anti-Ro-52 antibody were seen in IPF group. The most common chest images were honeycombing, bullae of lung and pneumonectasis in CTD-ILD group, while the presence of consolidation and small nodular shadow were more common in IPF group. The concurrence of respiratory failure was higher in IPF group compared with that in CTD-ILD group: 49.11%(83/169) vs. 13.07%(60/459), and there was significant difference (P <0.01). Conclusions Patients with CTD-ILD and IPF possess distinct characteristics. Overall assessment of clinical manifestation, autoantibody serology, high resolution chest CT and other indicator will be conducive to the differential diagnosis and treatment of ILD. Key words: Connective tissue disease; Idiopathic pulmonary fibrosis; Interstitial lung diseases