[1] Univ Milan, Pediat Area, Milan, Italy
[2] Fdn IRCCS Ca Grande Osped Maggiore Policlin, Milan, Italy
[3] IRCCS Osped Pediat Bambino Gesu, Div Rheumatol, Rome, Italy
[4] Univ Hlth Sci, Umraniye Tranining & Res Hosp, Div Pediat Rheumatol, Istanbul, Turkey
[5] Univ Zagreb, Div Paediat Rheumatol & Immunol, Zagreb, Croatia
[6] Univ Zagreb, Zagreb, Croatia
[7] PA Kyriakou Childrens Hosp, Athens, Greece
[8] St Petersburg State Pediat Med Univ, St Petersburg, Russia
[9] Childrens Hosp Zagreb, Zagreb, Croatia
[10] Univ Hosp Muenster, Munster, Germany
[11] Fdn IRCCS Ca Granda Osped Maggiore Policlin, Clin Marchi, Milan, Italy
[12] Bambino Gesu Pediat Hosp, Rome, Italy