[1] Inst Rhumatol Montreal, Montreal, PQ H2L 1S6, Canada
[2] Med Univ Vienna, Div Rheumatol, Dept Internal Med 3, Vienna, Austria
[3] Hietzing Hosp, Ctr Rheumat Dis, Dept Med 2, Vienna, Austria
[4] Leiden Univ, Med Ctr, Leiden, Netherlands
[5] Charite, Berlin, Germany
[6] Ctr Rheumat Dis, Bucharest, Romania
[7] Univ Hosp, Coimbra, Portugal
[8] Vrije Univ Amsterdam Med Ctr, Dept Med Humanities, Amsterdam, Netherlands
[9] Univ Paris 05, Cochin Hosp, Dept Rheumatol B, Paris, France
[10] Clin Univ St Luc, B-1200 Brussels, Belgium
[11] Univ Leeds, Acad Unit Musculoskeletal Dis, Leeds, W Yorkshire, England
[12] Hosp Santa Maria, Inst Med Mol & Rheumatol, Lisbon, Portugal
[13] Hosp Santa Maria, Bone Metab Dis Dept, Lisbon, Portugal
[14] Cornell Univ Hosp Special Surg, Weill Med Coll, New York, NY USA
[15] Univ Santiago, Hosp Clin Univ, E-15706 Santiago, Spain
[16] Med Univ Graz, Graz, Austria
[17] Istanbul Univ, Cerrahpasa Med Sch, Istanbul, Turkey
[18] Inst Clin Immunol, Erlangen, Germany
[19] Diakonhjemmet Hosp, Oslo, Norway
[20] Univ Sao Paulo, Div Rheumatol, Sao Paulo, Brazil
[21] Hosp Univ La Paz, Madrid, Spain
[22] Univ Pavia, IRCCS Policlin S Matteo, I-27100 Pavia, Italy
[23] Univ Sabana, Hosp Militar Cent, Bogota, Colombia
[24] Charles Univ Prague, Inst Rheumatol, Prague, Czech Republic
[25] Charles Univ Prague, Clin Rheumatol, Prague, Czech Republic
[26] Natl Inst Rheumatism & Physiotherapy, Budapest, Hungary
[27] Hosp Gen Dr Miguel Silva, Morelia, MI, Mexico
[28] Inst Rheumatol, Warsaw, Poland
[29] Keio Univ, Sch Med, Tokyo, Japan