Etiology of Bronchiectasis in a Cohort of 2047 Patients. An Analysis of the Spanish Historical Bronchiectasis Registry

Introduction: Bronchiectasis is caused by many diseases. Establishing its etiology is important for clinical and prognostic reasons. The aim of this study was to evaluate the etiology of bronchiectasis in a large patient sample and its possible relationship with demographic, clinical or severity factors, and to analyze differences between idiopathic disease, post-infectious disease, and disease caused by other factors. Methods: Multicenter, cross-sectional study of the SEPAR Spanish Historical Registry (RHEBQ-SEPAR). Adult patients with bronchiectasis followed by pulmonologists were included prospectively. Etiological studies were based on guidelines and standardized diagnostic tests included in the register, which were later included in the SEPAR guidelines on bronchiectasis. Results: A total of 2,047 patients from 36 Spanish hospitals were analyzed. Mean age was 64.9 years and 54.9% were women. Etiology was identified in 75.8% of cases (post-Infection: 30%; cystic fibrosis: 12.5%; immunodeficiencies: 9.4%; COPD: 7.8%; asthma: 5.4%; ciliary dyskinesia: 2.9%, and systemic diseases: 1.4%). The different etiologies presented different demographic, clinical, and microbiological factors. Post-infectious bronchiectasis and bronchiectasis caused by COPD and asthma were associated with an increased risk of poorer lung function. Patients with post-infectious bronchiectasis were older and were diagnosed later. Idiopathic bronchiectasis was more common in female non-smokers and was associated with better lung function, a higher body mass index, and a lower rate of Pseudomonas aeruginosa than bronchiectasis of known etiology. Conclusions: The etiology of bronchiectasis was identified in a large proportion of patients included in the RHEBQ-SEPAR registry. Different phenotypes associated with different causes could be identified. (C) 2016 SEPAR. Published by Elsevier Espana, S.L.U. All rights reserved.