Identification of a subgroup of non cystic fibrosis (CF) bronchiectasis patients with asthmatic traits

Background: Asthma, bronchiectasis, and COPD are the 3 most prevalent chronic airway diseases. They overlap with a higher frequency than expected. Although the overlapping relationship is not clear, the term "overlap syndrome" is well accepted. Many studies were performed in subjects with severe asthma and bronchiectasis, rarely "non severe" asthma was investigate in bronchiectasis subjects. Aims: To evaluate several tools to express asthma traits in bronchiectasis. Methods: Outpatient subjects with non-CF bronchiectasis, attending for the Pneumology Unit of Pisa, were evaluated. Baseline spirometry, reversibility test with salbutamol and/or methacholine challenge tests were performed. FeNO and/or induce sputum were collected too. Subjects known for primarily severe asthma are excluded. Results: Out of 208 subjects, 51 showed reversibility test and/or methacholine challenge test positive for asthma trait (24,5%). They don't differ from the others patients in terms of age, gender, detection of microbes in airways, but the pulmonary function (FEV1, RV expressed in % of predicted), the percentage of cells on sputum or blood (neutrophils, eosinophils) and FeNO values were different significally. Conclusion: The main tools to detect asthma, reversibility and methacholine challenge tests, are able to identify subjects with concomitant asthma and bronchiectasis. The identified group is significantly characterized with asthma traits, including probable eosinophilic trait. In the point of view of precision medicine, the treatment should be addressed on treatable traits and our results could have some implications to choice the treament in bronchiectasis with concomitant asthma features.