1. Department of Otorhinolaryngology, Head and Neck Surgery and VASCERN HHT Reference Centre, Essen University Hospital, University Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany
2. Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Center of the Johannes Gutenberg-University Mainz, 55101 Mainz, Germany
3. Institute of Immunology, Essen University Hospital, University Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany
4. Institute of Physiology, Essen University Hospital, University Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany
5. Department of Otorhinolaryngology, Head and Neck Surgery and VASCERN HHT Reference Centre, University Hospital of Marburg, Philipps-University of Marburg, Baldingerstrasse, 35042 Marburg, Germany