[1] Med Univ Vienna, Div Rheumatol, Vienna, Austria
[2] Hietzing Hosp, Vienna, Austria
[3] Univ Penn, Dept Rheumatol, Philadelphia, PA 19104 USA
[4] Charles Univ Prague, Inst Rheumatol, Prague, Czech Republic
[5] Charles Univ Prague, Clin Rheumatol, Prague, Czech Republic
[6] Univ Queensland, Dept Med, Brisbane, Qld 4000, Australia
[7] Univ Chile, Dept Rheumatol, Santiago, Chile
[8] Hosp San Juan Dios, Santiago, Chile
[9] Pfizer Inc, Dept Specialty Care, Collegeville, PA USA