[1] Leeds Gen Infirm, Leeds, W Yorkshire, England
[2] Leiden Univ, Leiden, Netherlands
[3] Hosp Univ La Paz, Madrid, Spain
[4] Inst Rheumatol, Prague, Czech Republic
[5] Tech Univ Lublin, PL-20618 Lublin, Poland
[6] Biogen Idec, San Diego, CA USA
[7] Roche Prod Ltd, Welwyn Garden City AL7 3AY, Herts, England
[8] Genentech Inc, San Francisco, CA 94080 USA