1. German Rheumatism Research Center, Leibniz Institute, Berlin, Germany.
2. German Rheumatism Research Center, Leibniz Institute, and Department of Rheumatology and Clinical Immunology, Charité Universitätsmedizin, Berlin, Germany.
3. Universitätsmedizin Rostock, Kinder- und Jugendklinik, Rostock, Germany.
4. Department of Paediatric Rheumatology, St. Josef-Stift, Sendenhorst, Germany.
5. Department of Paediatric Pneumology, Allergology and Neonatology, Children's Hospital, Medical School, Hannover, Germany.
6. German Center for Paediatric and Adolescent Rheumatology, Garmisch-Partenkirchen, Germany.
7. Department of Paediatric Rheumatology and Immunology, University Hospital, Münster, Germany.
8. Center for General Paediatrics and Neonatology, Asklepios Klinik Sankt Augustin, and Department of Paediatric and Adolescent Medicine, University Hospital, Cologne, Germany.
9. Center for Paediatric Rheumatology, Olgahospital, Stuttgart, Germany.
10. German Rheumatism Research Center, Leibniz Institute, Berlin, and Charité Universitätsmedizin Berlin, Paediatric Pneumology, Immunology and Critical Care Medicine and SPZ (Center for Chronically Sick Children), Berlin, Germany.
11. Labor Berlin - Charité Vivantes GmbH, Berlin, Germany.
12. Heinrich-Heine University Düsseldorf, Medical Faculty, Clinic of Paediatric Haematology, Oncology and Clinical Immunology, Düsseldorf, Germany.
13. Department of Paediatrics, Medical Faculty Carl Gustav Carus, Technical University, Dresden, Germany.
14. Prof.-Hess-Kinderklinik, Bremen, Germany.
15. German Rheumatism Research Center, Leibniz Institute, Berlin, Germany. sengler@drfz.de