1. Department of Medical Sciences, Allergy and Clinical Immunology AO Mauriziano, University of Torino, Torino, Italy
2. Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Milan, Italy
3. Respiratory Medicine Unit, National Health System, ASL Citta di Torino, Torino, Italy
4. Chest Department, Erasme University Hospital, Universite libre de Bruxelles, Brussels, Belgium
5. Department of Medical Sciences, Clinical Physiology, Uppsala University, Uppsala, Sweden