1 Justus-Liebig University Gießen, Campus Kerckhoff, Department of Rheumatology, Clinical Immunology, Osteology and Physical Medicine, Benekestr. 2-8, 61231 Bad Nauheim, Germany. Electronic address: n.schulz@kerckhoff-klinik.de.
2 Justus-Liebig University Gießen, Campus Kerckhoff, Department of Rheumatology, Clinical Immunology, Osteology and Physical Medicine, Benekestr. 2-8, 61231 Bad Nauheim, Germany.