[1] CSIC, Inst Parasitol & Biomed Lopez Neyra, Granada 18100, Spain
[2] Radboud Univ Nijmegen, Med Ctr, Dept Rheumatol, NL-6525 ED Nijmegen, Netherlands
[3] Hosp Valle De Hebron, Med Interna Serv, Barcelona, Spain
[4] Univ Milan, Referral Ctr Syst Autoimmune Dis, Milan, Italy
[5] Hosp Clin Univ, Med Interna Serv, Granada, Spain
[6] Hosp Clin Barcelona, Med Interna Serv, Barcelona, Spain
[7] Hosp 12 Octubre, Serv Reumatol, E-28041 Madrid, Spain
[8] Hosp Carlos Haya, Med Interna Serv, Malaga, Spain
[9] Hosp Virgen de las Nieves, Med Interna Serv, Granada, Spain
[10] Hosp Virgen del Rocio, Serv Inmunol, Seville, Spain
[11] Hosp Princesa, Serv Reumatol, Madrid, Spain
[12] Hosp Clin San Carlos, Serv Reumatol, Madrid, Spain
[13] Hosp Parc Tauli, Med Interna Serv, Sabadell, Spain
[14] Hosp Doctor Peset Aleixandre, Serv Reumatol, Valencia, Spain
[15] Hosp Reina Sofia, Serv Reumatol, Cordoba, Spain
[16] Hosp Virgen del Rocio, Med Interna Serv, Seville, Spain
[17] Hosp Santa Creu & Sant Pau, Serv Reumatol, Barcelona, Spain
[18] Univ Oviedo, Hosp Cent Asturias, Med Interna Serv, E-33080 Oviedo, Spain
[19] Hosp Carlos Haya, Serv Reumatol, Malaga, Spain
[20] Hosp Virgen de la Victoria, Serv Reumatol, Malaga, Spain
[21] Hosp Cruces, Med Interna Serv, Baracaldo, Spain
[22] Hosp Ramon & Cajal, Serv Reumatol, E-28034 Madrid, Spain
[23] Hosp del Mar, Serv Reumatol, Barcelona, Spain
[24] Hosp Univ Marques de Valdecilla, Serv Reumatol, Santander, Spain
[25] Univ Lund Hosp, Dept Rheumatol, S-22185 Lund, Sweden
[26] Charite, Dept Rheumatol & Clin Immunol, Berlin, Germany
[27] Hannover Med Sch, D-3000 Hannover, Germany
[28] Radboud Univ Nijmegen, Dept Human Genet, Med Ctr, NL-6525 ED Nijmegen, Netherlands
[29] Univ Med Ctr Utrecht, Dept Med Genet, Sect Complex Genet, Utrecht, Netherlands
[30] Catholic Univ Louvain, B-1200 Brussels, Belgium
[31] Univ Ghent, Dept Genet, B-9000 Ghent, Belgium
[32] Univ Leuven KULeuven, Leuven, Belgium
[33] Vrije Univ Amsterdam, Med Ctr, Dept Rheumatol, Amsterdam, Netherlands
[34] Leiden Univ, Med Ctr, Dept Rheumatol, Leiden, Netherlands
[35] Univ Glasgow, Glasgow, Lanark, Scotland
[36] Royal Free & Univ Coll Med Sch, Ctr Rheumatol, London WC1E 6BT, England
[37] Karolinska Inst, Stockholm, Sweden
[38] Oslo Univ Hosp, Rikshosp, Dept Rheumatol, Oslo, Norway
[39] Oslo Univ Hosp, Rikshosp, Inst Immunol, Oslo, Norway
[40] Spedali Civil Brescia, Serv Reumatol & Immunol Clin, I-25125 Brescia, Italy
[41] Newcastle Univ, Inst Cellular Med, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England
[42] Univ Cologne, Dept Dermatol, D-5000 Cologne, Germany
[43] Ruhr Univ Bochum, Bochum, Germany
[44] Univ Manchester, Manchester Acad Hlth Sci Ctr, Arthrit Res UK Epidemiol Unit, Manchester, Lancs, England