[1] Univ Med Ctr Utrecht, Dept Rheumatol & Clin Immunol, Utrecht, Netherlands
[2] Vrije Univ Amsterdam Med Ctr, Dept Clin Epidemiol & Biostat, Amsterdam, Netherlands
[3] Univ Crete, Clin Immunol & Allergy, Dept Internal Med, Rethimnon, Greece
[4] Univ Crete, Clin Immunol & Allergy, Dept Rheumatol, Rethimnon, Greece
[5] Charite Univ Med Berlin, Dept Rheumatol & Clin Immunol, Berlin, Germany
[6] Kings Coll London, Acad Dept Rheumatol, Sir Alfred Baring Garrod Clin Trials Unit, London WC1E 7HU, England
[7] Univ Genoa, Dept Internal Med, Res Lab, I-16126 Genoa, Italy
[8] Univ Genoa, Dept Internal Med, Div Rheumatol, I-16126 Genoa, Italy
[9] Hosp Univ Coimbra, Coimbra, Portugal
[10] Katholieke Univ Leuven Hosp, Dept Rheumatol, Louvain, Belgium
[11] Univ Paris 05, AP HP, Hop Cochin,Serv Med Interne, Ctr Reference Natl Plan Maladies Rares Vascularit, F-75270 Paris 06, France
[12] Karolinska Univ Hosp Huddinge, Karolinska Inst, Dept Rheumatol, Stockholm, Sweden
[13] Univ Bristol, Bristol Royal Infirm, Acad Rheumatol Unit, Bristol, Avon, England
[14] Univ Alberta, Dept Med, Div Rheumatol, Edmonton, AB, Canada
[15] Univ Alabama Birmingham, Div Clin Immunol & Rheumatol, Birmingham, AL USA
[16] Lund Univ, Dept Rheumatol, Lund, Sweden
[17] Hannover Med Sch, Div Rheumatol, Hannover, Germany