[1] Univ Birmingham, Rheumatol Res Grp, MRC Ctr Immune Regulat, Inst Biomed Res,Sch Immun & Infect,Coll Med & Den, Birmingham B15 2TT, W Midlands, England
[2] Sandwell & W Birmingham Hosp NHS Trust, Birmingham, W Midlands, England
[3] Univ Hosp Birmingham NHS Fdn Trust, Dept Rheumatol, Birmingham, W Midlands, England
[4] Charite, Dept Rheumatol & Clin Immunol, D-13353 Berlin, Germany
[5] Univ Crete, Dept Rheumatol Clin Immunol & Allergy, Sch Med, Iraklion, Greece
[6] Lund Univ, Dept Clin Sci, Rheumatol Sect, Skane Univ Hosp, Lund, Sweden
[7] Charles Univ Prague, Inst Rheumatol, Prague, Czech Republic
[8] Charles Univ Prague, Dept Rheumatol, Prague, Czech Republic
[9] Karolinska Inst, Rheumatol Unit, Dept Med, Solna, Sweden
[10] Karolinska Univ Hosp, Solna, Sweden
[11] Univ Hosp, Dept Publ Hlth & Clin Med, Umea, Sweden
[12] Med Univ Vienna, Dept Rheumatol, Vienna, Austria
[13] Inst Rheumatol, Dept Early Arthrit Diag, Warsaw, Poland
[14] Univ Zurich Hosp, Dept Rheumatol, CH-8091 Zurich, Switzerland