1Ospedale Pediatrico Bambino Gesù, Rome
2Coordinating Center, Cincinnati
3Coordinating Center, Genoa
4Hoffmann–La Roche, Welwyn Garden City
5Pediatric Rheumatology Department, Hospital Universitario La Fe, Valencia
6Rheumatology Section, Hospital Gral de Niños Pedro Elizalde, Buenos Aires
7Dipartimento di Pediatria, Università degli Studi di Genova, Genoa
8Department of Pediatrics, Division of Rheumatology, Hospital for Sick Children, University of Toronto, Toronto
9Department of Rheumatology, Great Ormond Street Hospital for Sick Children, London
10Division of Pediatric Rheumatology, Department of Pediatrics, University Hospital Gasthuisberg, Leuven
11Rheumatology Service, Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil, Departmento de Reumatologia, Hospital General de Mexico
12Pediatric Rheumatology, Connecticut Children's Medical Center, Hartford, Departmento de Reumatologia, Hospital General de Mexico
13Alder Hey Children's National Health Service Foundation Trust, Liverpool
14Faculty of Medicine, Universidad Nacional Autonoma de Mexico, Mexico City
15Department of Pediatrics and Adolescent Medicine, Charles University in Prague, and General University Hospital, Prague, Czech Republic
16Unidad de Reumatologia, Hospital Sor Maria Ludovica, La Plata
17Unidad de Reumatologia Pediatrica, Hospital Universitario La Paz, Madrid
18Centrum voor Kinderreumatologie, Universitair Ziekenhuis, Ghent
19Department of Pediatric Immunology and Rheumatology, Wilhelmina Kinderziekenhuis, Universitair Medisch Centrum, Utrecht, the Netherlands
20Department of Rheumatology, Oddzial Dzieci Starszych, Wojewodzki Specjalistyczny Szpital Dzieciecy Sw Ludwika, Krakow, Poland
21Department of Pediatrics, Unita di Reumatologia Pediatrica, Università di Padova, Padua