1. Department of Experimental Medicine, University of Rome “Tor Vergata”, Rome, Italy
2. Division of Respiratory Medicine, University Hospital “Fondazione Policlinico Tor Vergata”, Rome, Italy
3. Department of Clinical Medicine and Surgery, University of Naples “Federico II”, Naples, Italy
4. Istituti Clinici Scientifici Maugeri IRCCS, Pulmonary Rehabilitation Unit of Telese Terme Institute, Telese Terme, Italy