PDE4A and bronchiectasis: Some studies have attempted to identify the potential role of PDE4 inhibitors in the management of bronchiectasis because of their possibility to modulate neutrophil function, improve mucus and ciliary function, and the bronchodilator effect [6,20]. A phase II clinical trial using roflumilast in symptomatic bronchiectasis patients demonstrated improvement in health-related quality of life measured by the COPD assessment test score and the St.