1. Department of Rheumatology, Rheinisches Rheuma-Zentrum St. Elisabeth-Hospital, Meerbusch-Lank, Germany
2. Medical Faculty, Dept. & Hiller Research Unit for Rheumatology, Heinrich-Heine-University, Düsseldorf, Germany
3. Department of Internal Medicine III, Hematology and Oncology, University Hospital Regensburg, Regensburg, Germany
4. Department of Internal Medicine III, Hematology and Oncology, Regensburg Center for Interventional Immunology (RCI), University Hopital Regensburg, Regensburg, Germany
5. Faculty of Health/School of Medicine, Witten/Herdecke University, Witten, Germany