1. Department of Otorhinolaryngology, AZ St-Johns Hospital, Bruges, Belgium
2. Department of Otorhinolaryngology, University Hospital, Ghent, Belgium
3. Department of Otorhinolaryngology, University of Crete School of Medicine, Crete, Greece
4. Department of Otorhinolaryngology, University Hospital, Shimane, Japan
5. Department of Otorhinolaryngology, University Hospital, Leuven, Belgium
6. Laboratory of Immunoregulation, VIB Center for Inflammation Research, Ghent, Belgium
7. Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
8. Department of Pulmonary Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands