[1] Univ Med Ctr Utrecht, LTI, Utrecht, Netherlands
[2] Univ Med Ctr Utrecht, Dept Rheumatol & Clin Immunol, Utrecht, Netherlands
[3] Acad Med Ctr Amsterdam, Dept Clin Immunol & Rheumatol, Amsterdam, Netherlands
[4] GlaxoSmithKline, Stevenage, Herts, England