[1] Royal Brompton Hosp, Interstitial Lung Dis Unit, London SW3 6LR, England
[2] Univ Munich, Internal Med Pulm Div 1, Munich, Germany
[3] Ruhr Univ Bochum, Dept Internal Med Resp & Crit Care 3, Bochum, Germany
[4] Univ Duisburg Essen, Fac Med, Essen, Germany
[5] Ruhrlandklin, Essen, Germany
[6] Hosp Louis Pradel, Serv Pneumol, Lyon, France
[7] Pierantoni Morgagni Hosp, Forli, Italy