[1] Univ Birmingham, Sch Med, Div Immun & Infect, Rheumatol Res Grp, Birmingham B15 2TT, W Midlands, England
[2] Univ Crete, Sch Med, Iraklion, Greece
[3] Univ Ioannina, Sch Med, Clin Trials & Evidence Based Med Unit, Dept Hyg & Epidemiol, GR-45110 Ioannina, Greece
[4] Laiko Hosp, Dept Nephrol & Transplantat Med, Athens, Greece
[5] Univ Pisa, Cattedra Reumatol, Pisa, Italy
[6] Hosp Clin Barcelona, Dept Autoimmune Dis, Barcelona, Catalonia, Spain
[7] Inst Rheumatol, Prague, Czech Republic
[8] Rigshosp, Dept Rheumatol, Oslo, Norway
[9] Catholic Univ Louvain, Clin Univ St Luc, Dept Rheumatol, B-1200 Brussels, Belgium
[10] Leiden Univ, Med Ctr, Dept Rheumatol, Leiden, Netherlands
[11] Univ Coll London Hosp, Ctr Rheumatol, London, England
[12] Univ Groningen, Univ Med Ctr Groningen, Dept Clin Immunol, NL-9713 AV Groningen, Netherlands
[13] St Thomas Hosp, Rayne Inst, Lupus Res Unit, London SE1 7EH, England
[14] Grp Hosp Pitie Salpetriere, Serv Med Interne, F-75634 Paris, France
[15] Univ Dusseldorf, Clin Endocrinol Diabetol & Rheumatol, Dusseldorf, Germany
[16] Med Univ Vienna, Dept Rheumatol, Vienna, Austria
[17] Univ Lund Hosp, Dept Rheumatol, S-22185 Lund, Sweden
[18] Osped Civile Brescia, Rheumatol & Immunol Clin, Brescia, Italy
[19] Karolinska Univ Hosp, Karolinska Inst, Dept Med, Rheumatol Unit, Solna, Sweden