[1] Univ Politecn Marche, Dept Biomed Sci & Publ Hlth, Ancona, Italy
[2] Azienda Osped Riuniti, Pulm Dis Unit, Dept Internal Med, Ancona, Italy
[3] Univ Parma, Dept Clin & Expt Med, Resp Dis & Lung Funct Unit, Parma, Italy
[4] Royal Brompton Hosp, Interstitial Lung Dis Unit, London, England