1. Department of Nephrology and Rheumatology, University Medical Center Göttingen, 37075 Göttingen, Germany
2. Institute of Pathology, University Medical Center Göttingen, 37075 Göttingen, Germany
3. SYNLAB Pathology Hannover, SYNLAB Holding Germany, 86156 Augsburg, Germany
4. Institute of Pathology, Klinikum Bremen-Mitte, School of Medicine of the University of Göttingen, 28205 Bremen, Germany
5. Department of Rheumatology and Clinical Immunology, St. Josef-Stift Sendenhorst, 48324 Sendenhorst, Germany