[1] Rheumatol Ctr Rhineland Palatinate, Kaiser Wilhelm Str 9-11, D-55543 Bad Kreuznach, Germany
[2] Johannes Gutenberg Univ Mainz, Univ Med Ctr, Div Rheumatol & Clin Immunol, Dept Internal Med 1, D-55131 Mainz, Germany
[3] Helios Clin, Dept Internal Med, D-47805 Krefeld, Germany
[4] Univ Pavia, Dept Rheumatol, I-27100 Pavia, Italy
[5] IRCCS Policlin S Matteo Fdn Pavia, I-27100 Pavia, Italy
[6] Ruhr Univ Bochum, Rheumazentrum Ruhrgebiet Herne, D-44649 Herne, Germany
[7] Univ Crete, Sch Med, Dept Internal Med & Rheumatol, Iraklion 71500, Greece
[8] Univ Hosp Munster, Dept Internal Med D, Sect Rheumatol & Clin Immunol, D-48149 Munster, Germany