1. Children's Hospital of Eastern OntarioOttawa Ontario Canada
2. ASST Mantova, C. Poma HospitalMantova Italy
3. Park‐Klinik WeissenseeBerlin Germany
4. National Institute of Rheumatology and PhysiotherapyBudapest Hungary
5. Centre Hospitalier de l'Université de SherbrookeSherbrooke Quebec Canada
6. MC Groep HospitalsLelystad The Netherlands
7. Hospital Universitario Severo OchoaMadrid Spain
8. Hospital Universitario Universidad Autonoma de Nuevo Leon-Monterrey, Nuevo Leon Mexico
9. Bicetre University HospitalLe Kremlin Bicetre France
10. Aarhus University HospitalAarhus Denmark
11. Instituto Nacional de RehabilitacionMexico City Mexico
12. Università degli Studi di TorinoTurin Italy
13. Hôpital de la Cavale BlancheBrest France
14. Istituto Giannina GasliniGenoa Italy
15. Rikshospitalet University HospitalOslo Norway
16. Ospedale Pediatrico Bambino GesuRome Italy
17. Vall d'Hebron University HospitalBarcelona Spain
18. Hospital Universitario Ramon y CajalMadrid Spain
19. Hospital General Universitario Gregorio MarañónMadrid Spain
20. Charité University HospitalBerlin Germany
21. Oslo University HospitalRikshospitalet Oslo Norway
22. Medisch Centrum AlkmaarAlkmaar The Netherlands
23. Cincinnati Children's HospitalCincinnati Ohio
24. Pediatric Rheumatology Research InstituteBad Bramstedt Germany
25. Emory UniversityAtlanta Georgia
26. University Clinical CenterNis Serbia
27. Asklepios Hospital WeissenfelsWeissenfels Germany
28. Ambroise Paré Hospital, Boulogne‐Billancourt and INSERM U1173, Laboratoire d'Excellence INFLAMEX, University Paris Ouest-Versailles St.-Quentin, Saint Quentin en Yvelines France