Wolfgang Kruis1, Phuong Nguyen1, Julia Morgenstern1, Wolfgang Ramlow2, Axel Dignaß3, Andreas Stallmach4, Uta Drebber5. 1. Evangelisches Krankenhaus Kalk, University of Cologne, Germany. 2. Apheresis Center Rostock (ACR), Rostock, Germany. 3. Department of Medicine I, Agaplesion Markus Hospital and Crohn Colitis Clinical Research Center Rhein-Main, Frankfurt/Main, Germany. 4. Department of Internal Medicine IV (Gastroenterology, Hepatology, Infectious Diseases), University Hospital of Jena, Jena, Germany. 5. Department of Pathology, University of Cologne, Germany.