[1] Hamburger Zentrum Kinder & Jugendrheumatol, Hamburg, Germany
[2] German Rheumatism Res Ctr, Epidemiol Unit, Berlin, Germany
[3] Univ Childrens Hosp, Pediat Cathedra, Riga, Latvia
[4] Hosp Pediat Prof Dr Juan P Garrahan MD, Serv Immunol & Rheumatol, Buenos Aires, DF, Argentina
[5] Univ Fed Sao Paulo, Pediat, Sao Paulo, Brazil
[6] Univ Fed Sao Paulo, Pediat Rheumatol Unit, Sao Paulo, Brazil
[7] Univ Florence, Dept Paediat, Florence, Italy
[8] Anna Meyer Childrens Hosp, Florence, Italy
[9] State Pediat Med Univ, St Petersburg, Russia
[10] Univ Childrens Hosp, Ljubljana, Slovenia
[11] Hosp Garcia de Orta, Rheumatol, Almada, Portugal
[12] Univ Childrenhosp, Pediat Rheumatol, Tubingen, Germany
[13] Gen Univ Hosp Prague, Dept Pediat & Adolescent Med, Pediat Rheumatol Unit, Prague, Czech Republic
[14] Univ Fed Rio de Janeiro, Rio De Janeiro, Brazil
[15] Hosp Ninos Dr Orlando Alasia, Santa Fe, Santa Fe, Argentina
[16] Univ Klin Kinder & Jugendheilkunde, Innsbruck, Austria
[17] Great Ormond St Hosp Sick Children, Paediat Rheumatol Dept, London WC1N 3JH, England
[18] Univ Hosp Ramon y Cajal, Dept Rheumatol, Madrid, Spain
[19] Tel Aviv Univ, Schneider Childrens Med Ctr, Pediat Rheumatol Unit, Petah Tiqwa, Israel
[20] Pediat Rheumatol, Madras, Tamil Nadu, India
[21] Univ Med Berlin, Charite, Berlin, Germany
[22] Charite, Chidlrens Hosp, D-13353 Berlin, Germany
[23] Rigshosp, DK-2100 Copenhagen, Denmark
[24] UPMC, Childrens Hosp Pittsburgh, Scleroderma Ctr Pittsburgh, Pediat Rheumatol, Pittsburgh, PA USA
[25] Meir Med Ctr, Kefar Sava, Israel
[26] Hamburg Ctr Pediat & Adolescent Rheumatol, Hamburg, Germany