[1] Univ Calif Los Angeles, Dept Rheumatol, Los Angeles, CA 90025 USA
[2] Univ Toronto, Dept Rheumatol, Toronto, ON, Canada
[3] Rheumazentrum Ruhrgebiet, Herne, Germany
[4] Leiden Univ, Med Ctr, Leiden, Netherlands
[5] IRCCS Osped Pediat Bambino Gesu, Lab Reumatol, Rome, Italy
[6] Charite, Dept Rheumatol & Clin Immunol, D-13353 Berlin, Germany
[7] Charite, Inst Transfus Med, D-13353 Berlin, Germany
[8] Univ Leeds, Leeds Inst Mol Med, Biomed Res Unit, Sect Musculoskeletal Dis, Leeds, W Yorkshire, England
[9] Univ Leeds, Teaching Hosp Trust, Leeds, W Yorkshire, England
[10] Univ Texas SW Med Ctr Dallas, Dallas, TX 75390 USA
[11] Hosp Special Surg, New York, NY 10021 USA
[12] Univ Erlangen Nurnberg, Dept Rheumatol, D-91054 Erlangen, Germany
[13] Univ Calif San Diego, Dept Rheumatol Allergy Immunol, La Jolla, CA 92093 USA
[14] Guys Hosp, Dept Rheumatol, London SE1 9RT, England
[15] Swedish Med Ctr, Seattle, WA USA
[16] Univ Washington, Seattle, WA 98195 USA
[17] Univ Cologne, Dept Internal Med 1, D-50931 Cologne, Germany
[18] Charite Campus Benjamin Franklin, Dept Med Rheumatol, Berlin, Germany
[19] Case Western Reserve Soc, Metrohlth Med Ctr, Div Rheumatol, Cleveland, OH USA
[20] Krankenhaus Lainz, Dept Med 2, Vienna, Austria
[21] Med Univ Vienna, Dept Rheumatol, Vienna, Austria
[22] Radboud Univ Nijmegen, Nijmegen Med Ctr, Dept Rheumatol, NL-6525 ED Nijmegen, Netherlands
[23] Cedars Sinai Med Ctr, Div Rheumatol, Los Angeles, CA 90048 USA
[24] Oregon Hlth & Sci Univ, Dept Infect Dis, Portland, OR 97201 USA