1. Department of Gastroenterology, Hepatology, and Infectiology, Otto-von-Guericke University Hospital Magdeburg, Magdeburg, Germany
2. Institute of Pathology and Cytology, Augusta Hospital, Bochum, Germany
3. Department of Gastroenterology and Hepatology, University Hospital Essen (AöR), Essen, Germany
4. Department of Internal Medicine, Evangelisches Krankenhaus (Protestant Hospital), Hattingen, Germany