1. Unit of Respiratory Disease, Cardiothoracic and Vascular Department, IRCCS Policlinico San Matteo, Viale Golgi 19, 27100 Pavia, Italy
2. Department of Internal Medicine and Pharmacology, University of Pavia, 27100 Pavia, Italy
3. Ospedale Pederzoli, Peschiera del Garda, 37121 Verona, Italy