1 National Coordinating Reference Centre for Rare Pulmonary Diseases, Department of Respiratory Medicine, Louis Pradel Hospital, Hospices Civils de Lyon, ERN-LUNG, UMR 754, INRAE, Claude Bernard University Lyon 1, Lyon, France vincent.cottin@chu-lyon.fr.
2 Department of Pneumonology and Thoracic Oncology, North Hospital, University Hospital of Saint-Etienne, Saint-Etienne, France.
3 Hospital Universitario de la Princesa, Universitad Autónoma de Madrid, Madrid, Spain.
4 Division of Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI, USA.