[1] Univ Calif Los Angeles, Div Rheumatol, Los Angeles, CA USA
[2] Leiden Univ, Med Ctr, Dept Rheumatol, Leiden, Netherlands
[3] Univ Erlangen Nurnberg, Inst Clin Immunol, Dept Internal Med 3, Erlangen, Germany
[4] Vienna Gen Hosp, Clin Internal Med 3, Inst Rheumatol, Vienna, Austria
[5] Charite Hosp, Dept Rheumatol & Clin Immunol, Berlin, Germany
[6] Univ Utrecht, Med Ctr, Dept Rheumatol & Clin Immunol, Utrecht, Netherlands
[7] Hop Cochin, Inst Rhumatol, Paris, France
[8] Univ Leeds, Gen Infirm, Dept Rheumatol, Leeds LS1 3EX, W Yorkshire, England
[9] Mt Sinai Hosp, Dept Rheumatol, Toronto, ON, Canada
[10] Karolinska Hosp, Dept Med, Rheumatol Unit, S-10401 Stockholm, Sweden
[11] Swedish Med Ctr, Med Ctr, Seattle, WA USA