Idiopathic pulmonary fibrosis--clinical presentation, outcome and baseline prognostic factors in a Portuguese cohort

Abstract

Introduction: Idiopathic Pulmonary Fibrosis (IPF) is the most common disease in the subgroup of idiopathic interstitial pneumonias. It is inevitably associated to a bad prognosis, although assuming a highly variable clinical course. Methods: Patients with IPF, observed at Interstitial Lung Diseases outpatient clinic of Centro Hospitalar de São João – Porto, Portugal, were identified and clinical, functional, radiological and bronchoalveolar lavage (BAL) parameters were reviewed. Their clinical course and survival were analyzed in order to identify prognostic factors. Results: Eighty-one patients were included, with a mean age at diagnosis of 63.8 years old. At diagnosis, the main functional abnormalities were restrictive physiology, reduced lung diffusion and exercise capacity impairment. Clinical course was mainly slowly progressive (72.3%). Ten patients (13.2%) had a rapid progression and 11 (14.5%) patients had an acute exacerbation during the course of the disease. IPF's rapid progression was associated to a higher functional impairment at diagnosis, namely in what is related with Functional Vital Capacity (FVC) and Total Lung Capacity (TLC). Median survival was 36 months. A significant difference in survival was observed among different types of clinical course – 41 months for slow progressors and 9 months for rapid progressors. Lower levels of FVC, TLC, six-minute walk test (6MWT) distance and rest PaO2, and higher BAL neutrophil count were associated with poorer survival in univariate analysis. Conclusion: The analysis of this group of IPF patients confirms two clearly different phenotypes, slow and rapid progressors. Those phenotypes seem to have different presentations and a remarkably different natural history. These results could mean different physiopathologic pathways, which could implicate different therapeutic approaches.