1. Institute of Rheumatology, 12800 Prague, Czech Republic
2. Department of Rheumatology, First Faculty of Medicine, Charles University, 12800 Prague, Czech Republic
3. Department of Physiotherapy, Faculty of Physical Education and Sport, Charles University, 16252 Prague, Czech Republic
4. Department of Internal Medicine III and Institute for Clinical Immunology, University of Erlangen-Nuremberg, 91054 Erlangen, Germany