1. Department of Rheumatology, University Hospital Basel, Basel, Switzerland;
2. Hôpital Saint Antoine, service d'hématologie et thérapie cellulaire, Assistance Publique des Hopitaux de Paris (AP-HP), European Blood and Marrow Transplantation office, Paris, France;
3. Haematology Department, Careggi University Hospital, Florence, Italy;
4. Newcastle General Hospital, Newcastle upon Tyne, United Kingdom;
5. Department of Rheumatology and Clinical Immunology, Charité, Berlin, Germany;
6. Department of Biomedicine, Division of Rheumatology, University of Florence, Florence, Italy;
7. Department of Haematology II, Ospedale San Martino, Genova, Italy;
8. Neurology and Haematology, George Papanicolau Hospital, Thessaloniki, Greece;
9. Service d'Immunologie Clinique, Université de Strasbourg, Strasbourg, France;
10. Paediatric Haematology and Endocrinology, University Children's Hospital Tübingen, Tübingen, Germany;
11. University Medical Center Utrecht, Utrecht, The Netherlands;
12. Section of Musculoskeletal Disease, University of Leeds, Chapel Allerton Hospital, Leeds, United Kingdom;
13. Hospital Universitari Son Espases, Palma De Mallorca, Spain;
14. Department of Hematology, Institute of Hematology & Oncology, Hospital Clinic, Barcelona, Spain;
15. Department of Neurology, University Hospitals Leuven, Leuven, Belgium;
16. Department of Pediatrics, University of Jena, Jena, Germany;
17. Division of Immunology/Hematology/BMT, University Children's Hospital, Zürich, Switzerland;
18. Charles University Hospital, Prague, Czech Republic;
19. Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands;
20. Department of Hematology & Oncology, Central Clinical Hospital, Medical University of Warsaw, Warsaw, Poland;
21. Department of Haematology, Sheffield Teaching Hospitals National Health Service (NHS) Foundation Trust, and Department of Oncology, University of Sheffield, Sheffield, United Kingdom;
22. Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom;
23. Department of Pediatrics, University of Gothenburg, Gothenburg, Sweden;
24. Department of Hematology, University Hospital, Lund, Sweden;
25. Dipartimento di Pediatria, Clinica di Oncoematologia Pediatrica, Padova, Italy;
26. Department of Hematology, Hôpital Saint Antoine, AP-HP, and Université Pierre et Marie Curie, Paris, France;
27. European Blood and Marrow Transplantation Study Office, Faculté de Médecine Saint-Antoine, Unite Mixte de Recherche S938, CEREST-TC European Blood and Marrow Transplantation, Paris, France;
28. Department of Hematology and Rheumatology University Hospital Tübingen, Tübingen, Germany;
29. Department of Internal Medicine, Hopital Claude Huriez, Lille, France;
30. Clinical Research Unit, Eurocord office, Hôpital Saint Louis AP-HP, Paris, France; and
31. Internal Medicine and Vascular Pathology Unit, Inserm U976, Saint Louis Hospital, Paris, France