[1] Univ Hosp Leuven, Dept Resp Dis, Unit Interstitial Lung Dis, Herestr 49, BE-3000 Leuven, Belgium
[2] Erasmus MC, Univ Med Ctr, Dept Resp Med, Rotterdam, Netherlands
[3] Univ Libre Bruxelles, Hop Erasme, Dept Pneumol, Brussels, Belgium
[4] Univ Athens, Dept Med, Interstitial Lung Dis Unit, Acad Dept Pneumonol 1, Athens, Greece
[5] Onze Lieve Vrouw Hosp, Dept Resp Med, Amsterdam, Netherlands
[6] Coimbra Univ Hosp, Dept Pneumol, Coimbra, Portugal
[7] Aarhus Univ Hosp, Dept Resp Med & Allergol, Aarhus, Denmark
[8] Univ Gothenburg, Inst Med, Dept Internal Med Resp Med & Allergol, Gothenburg, Sweden
[9] Univ Athens, Med Sch, Gen Univ Hosp Attikon, Pulm Med Dept 2, Athens, Greece
[10] Hosp Sao Joao, Dept Pulmonol, Porto, Portugal
[11] Herlev & Gentofte Univ Hosp, Copenhagen, Denmark
[12] St Antonius Hosp, ILD Ctr Excellence, Dept Pulmonol, Nieuwegein, Netherlands
[13] Aarhus Univ Hosp, Dept Resp Dis & Allergy, Ctr Rare Lung Dis, Aarhus, Denmark