[1] Hamburger Zentrum Kinder & Jugendrheumatol, Hamburg, Germany
[2] Univ Childrens Hosp, Ljubljana, Romania
[3] Med Univ Innsbruck, A-6020 Innsbruck, Austria
[4] Meyer Childrens Hosp, Florence, Italy
[5] Charite, Berlin, Germany
[6] Hosp Pediat, Buenos Aires, DF, Argentina
[7] Meir Med Ctr, Kfar Saba, BELARUS
[8] Univ Fed Sao Paulo, Sao Paulo, Brazil
[9] St Petersburg State Pediat Med Acad, St Petersburg, Russia
[10] Dept Pediat, Prague, Czech Republic
[11] Univ Estado, Rio De Janeiro, Brazil
[12] DRFZ, Berlin, Germany
[13] St Elizabeth Hosp, Lorrach, Germany