[1] Symmetron Ltd, 8 Devonshire Sq, London, England
[2] Univ Libre Bruxelles ULB, Erasme Univ Hosp, Dept Resp Med, Brussels, Belgium
[3] CHU UCL Namur Site Godinne, Dept Pneumol, Yvoir, Belgium
[4] Univ Catholique Louvain UCLouvain, Clin Univ St Luc, Dept Pneumol, Brussels, Belgium
[5] Univ Hosp Leuven, Dept Resp Med, Unit Interstitial Lung Dis, Louvain, Belgium
[6] Boehringer Ingelheim GmbH & Co KG, Amsterdam, Netherlands