Abstract
Introduction Pulmonary involvement in microscopic polyangiitis (MPA) is common, presented with multiple changes on chest images. Little is known about what is the clinical features to the different image patterns. Aims To explore the clinical features of MPA with different types of interstitial pneumonitis on chest HRCT. Methods The study included 75 consecutive patients (male/female ratio, 1.14:1, age 67.39±11.15 years) with MPA combined pulmonary involvement who were admitted in Beijing Chao-Yang Hospital of Capital Medical University from Aug. 2003 to Aug. 2013. The clinical, imaging and laboratory data were collected and analyzed. Results 36 patients (36/75, 48.0%) had usual interstitial pneumonia(UIP)-like pattern on chest HRCT and called as MPA/UIP. The remained 39 patients had non UIP-like pattern and named as MPA/non UIP. Compared with MPA/non UIP patients, MPA/UIP patients mostly had a chronic course(28/36 vs 18/39, P =0.009), poorer lung function [DLCO%pred (29.87±15.80)% vs (75.44±33.22)%, P<0.001, DLCO/VA%pred[(50.74±21.00)% vs (93.62±25.38)%, P<0.001], seldom proteinuria(19/36 vs 28/39, P=0.047) and/or hematuria(27/36 vs 34/39, P=0.046), and mild proteinuria [24h urine protein excretion(777.10±799.05)mg/24h vs (1361.61±910.61)mg/24h, P=0.032]. Conclusions Near 50% of MPA patients presented with lung involvement characterized by UIP-like pattern on HRCT. MPA patients with UIP tend to have a chronic disease course and seldom proteinuria and/or hematuria. Thus, differentiated diagnosis should be made between MPA and idiopathic interstitial pneumonia.
- © 2014 ERS
