1. Department of Rheumatology, Institute Clinical Medicine, University of Tromsø and University Hospital, Tromsø, Norway,
2. Department of Rheumatology, University Hospital, Zagreb, Croatia
3. 3rd Department of Internal Medicine, Medical University of Debrecen, Debrecen, Hungary
4. Rheumatology Unit, Istituto Ortopedico Gaetano Pini, Milano, Italy
5. Institute of Rheumatology, RAMS, Moscow, Russia
6. Universita degli Studi di Pisa, Department of Rheumatology, Pisa, Italy
7. Department of Connective Tissue Diseases, Institute of Rheumatology, Warsaw, Poland
8. Department of Rheumatology, University of Szeged and Szeged City Hospital, Szeged, Hungary
9. Department of Rheumatology, Dr Peter Drzaj Hospital, Ljubljana, Slovenia
10. Department of Rheumatology, Heinrich-Heine University, Düsseldorf, Germany
11. Department of Pathophysiology, School of Medicine, National University of Athens, Athens, Greece
12. Department of Rheumatology, Ikazia Ziekenhuis, Rotterdam, The Netherlands