Clinical features of usual interstitial pneumonia-correlation between idiopathic pulmonary fibrosis and connective tissue disease associated with usual interstitial pneumonia

Abstract

Introduction The Usual Interstitial Pneumonia(UIP) is a radiological entity characterized by thickened interlobar septae in the lower lobes, involving subpleural spaces bilaterally, resulting with honeycombing, in its advanced stage. This is an idiopathic form termed Idiopathic Pulmonary Fibrosis (IPF), which may be associated with Connective Tissue Disorders (UIP-CTD).

Material and Methods A retrospective analysis of HRCT diagnosed UIP patients between 2004-2014. The obtained data were statistically processed (significance p<0.05).

Results The total of 103UIP patients (62IPF and 41UIP-CTD) ware analysed. CTD patients had RA(n=21), systemic sclerosis(n=11), Sjögren syndrome(n=8), SLE(n=2), and polymyositis(n=1). The IPF group included 65% males and 60% females of the UIP-CTD group. Smokers made 59% and 27% of the IPF and UIP-CTD group. IPF group had severer dyspnoea, cough, and mean mMRC dyspnoea score. Clubbing was registered in IPF patents (39% vs.19%). Autoantibodies were positive in 35% of IPF patients(RF,ANA). IPF group had lower mean DLco, TLC and RV. Radiological findings were significantly different in the two groups, with honeycomb lungs 87% and45% of the IPF and UIP-CTD group. Immunesuppressive treatment was more commonly administered in the UIP-CTD group (81% vs. 52%).

Conclusion IPF patients might be diagnosed lately since those patients have a longer history of symptoms, reduced lung volumes and DLco, and more common honeycombing in HRCT. Typical extrapulmonary symptoms could alert physicians to investigate CTD or in CTD patients' pulmonary symptoms may lead to investigate pulmonary involvement.