1. Division of Rheumatology, Medizinische Klinik und Poliklinik IV, University Hospital Munich, Germany
2. Rheumatologie, Klinikum Nuernberg, Germany
3. Division of Rheumatology, Department of Medicine III, University Clinical Center Carl Gustav Carus, Germany
4. Rheumatology and Clinical Immunology, Charité University Hospital, Germany
5. Clinic for Rheumatology, Heinrich-Heine-University, Germany
6. Center for Rheumatic Diseases, Germany
7. Department of Internal Medicine I, University of Regensburg, Germany
8. Analytica International GmbH, Germany
9. Department of Internal Medicine III, Klinikum Fulda, Germany
10. 0Rheumatology Outpatient Clinic, Germany
11. 1Department of Nephrology, Hannover Medical School, Germany
12. 2Internal Medicine II, Barmherzige Brueder Hospital, Germany
13. 3Department of Rheumatology, University Hospital of Cologne, Germany
14. 4Division of Rheumatology and Clinical Immunology, Dept. of Internal Medicine, Johannes Gutenberg-Universität, Germany
15. 5Department of Rheumatology and Clinical Immunology, Kliniken Essen-Sued, Germany
16. 6Medizinische Klinik and Poliklinik II, University of Wuerzburg, Germany
17. 7Department of Rheumatology, Internal Medicine I, Krankenhaus Dresden-Friedrichstadt, Germany
18. 8Department of Rheumatology, Evangelisches Fachkrankenhaus Ratingen, Germany