[1] Hietzing Hosp, Dept Internal Med 2, Ctr Rheumat Dis, A-1130 Vienna, Austria
[2] Rheumazentrum Ruhrgebiet, Dept Rheumatol, Herne, Germany
[3] Hop Cochin, Dept Rheumatol, F-75674 Paris, France
[4] Univ Leeds, Leeds Inst Rheumat & Musculoskeletal Med, Chapel Allerton Hosp, Leeds, W Yorkshire, England
[5] Leeds Teaching Hosp NHS Trust, NIHR Leeds Musculoskeletal Biomed Res Unit, Leeds, W Yorkshire, England
[6] St Vincents Univ Hosp, Dept Rheumatol, Dublin 4, Ireland
[7] Univ Calif San Diego, La Jolla, CA 92093 USA
[8] Diakonhjemmet Hosp, Dept Rheumatol, Oslo, Norway
[9] AMC Amsterdam, Dept Clin Immunol & Rheumatol, Amsterdam, Netherlands
[10] Univ Munster, Dept Dermatol, D-48149 Munster, Germany
[11] Univ Washington, Dept Rheumatol, Seattle, WA 98195 USA
[12] San Carlo Hosp Potenza & Madonna delle Grazie, Rheumatol Dept Lucania, Potenza, Italy
[13] Univ Texas Houston, Dept Rheumatol, Houston, TX USA
[14] Univ Rochester, Med Ctr, Dept Rheumatol, Rochester, NY 14642 USA
[15] Charite, Dept Med, D-13353 Berlin, Germany
[16] Univ Clin Benjamin Franklin, Dept Med 1, Berlin, Germany
[17] Hietzing Hosp, Dept Rheumatol, A-1130 Vienna, Austria
[18] Vrije Univ Amsterdam Med Ctr, Dept Med Humanities, Amsterdam, Netherlands
[19] Leiden Univ, Dept Rheumatol, Med Ctr, Leiden, Netherlands