[1] Univ Texas Southwestern Med Ctr Dallas, Dallas, TX 75390 USA
[2] Sanofi Genzyme, Bridgewater, NJ USA
[3] Regeneron Pharmaceut Inc, 777 Old Saw Mill River Rd, Tarrytown, NY 10591 USA
[4] Leiden Univ, Med Ctr, Leiden, Netherlands
[5] Complejo Hosp Univ Santiago, IDIS, Santiago, Spain
[6] Buenos Aires Univ, Sch Med, Buenos Aires, DF, Argentina
[7] Res Rheumatol Inst, Moscow, Russia
[8] Univ Genoa, Dept Internal Med, Genoa, Italy
[9] Charite Univ Med Berlin, Berlin, Germany