1 Division of Rheumatology, Medical Department III - Endocrinology, Nephrology and Rheumatology, Department of Internal Medicine, Neurology and Dermatology, University of Leipzig Medical Centre, Leipzig, Germany. marco.krasselt@medizin.uni-leipzig.de.
2 Division of Rheumatology, Medical Department III - Endocrinology, Nephrology and Rheumatology, Department of Internal Medicine, Neurology and Dermatology, University of Leipzig Medical Centre, Leipzig, Germany.