[1] Univ Padua, Dept Cardiac Thorac Vasc Sci & Publ Hlth, Padua, Italy
[2] ASST Spedali Civili, Referral Ctr Alpha 1 Antitrypsin Deficiency, Brescia, Italy
[3] AOU Cagliari, Dept Internal Med, Cagliari, Italy
[4] Civil Hosp, Resp Pathophysiol & Ventilat Unit, Saluzzo, Cuneo, Italy
[5] Univ Siena, Dept Med & Surg Sci & Neurosci, Resp Dis Unit, Siena, Italy
[6] Univ Naples Federico II, Dept Clin Med & Surg, I-80131 Naples, Italy