1. Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
2. Department of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology, Lund University, Lund, Sweden
3. Department of Rheumatology, Skåne University Hospital, Lund, Sweden
4. Department of Medicine, Division of Clinical Immunology and Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA
5. Rheumatology Research Group, School of Immunity and Infection, College of Medical and Dental Sciences University of Birmingham, Birmingham, UK
6. Department of Clinical Pharmacology, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
7. Division of Rheumatology, Department of Medicine, Centre Hospitalier Universitaire (CHU) de Québec Axe Maladies Infectieuses et Immunitaires, CRCHU de Québec, Université Laval, Quebec City, Quebec, Canada
8. Arthritis Research UK Centre for Epidemiology, Centre for Musculoskeletal Research, Institute of Inflammation and Repair, Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, UK
9. NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, UK
10. Centre for Rheumatology, Research Division of Medicine, London, UK
11. Cedars-Sinai Medical Center, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
12. Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
13. Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Korea
14. Division of Rheumatology, Departments of Medicine and Pathology Capital Health and Dalhousie University, Halifax, Nova Scotia, Canada
15. Mount Sinai Hospital and University Health Network, Toronto, Ontario, Canada
16. Divisions of Clinical Epidemiology and Rheumatology, McGill University Health Centre, Montreal, Quebec, Canada
17. Feinstein Institute for Medical Research, Manhasset, NY, USA
18. Department of Medicine, Division of Rheumatology, Allegheny Singer Research Institute, Allegheny General Hospital, Pittsburgh, PA, USA
19. Toronto Western Hospital Toronto, Ontario, Canada
20. Division of Rheumatology, Allergy and Immunology, UCSD School of Medicine, La Jolla, CA, USA
21. North Dallas Dermatology Associates, Dallas, TX, USA
22. Philadelphia VA Medical Center and University of Pennsylvania, Philadelphia, PA, USA
23. Lanarkshire Centre for Rheumatology and Hairmyres Hospital, East Kilbride, UK
24. Autoimmune Diseases Research Unit, Hospital Universitario Cruces Universidad del Pais Vasco, Barakaldo, Spain
25. Rayne Institute and St Thomas' Hospital London, UK
26. Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
27. New York University, New York, NY, USA
28. Ysbyty Gwynedd, Bangor, UK
29. University of North Carolina, Chapel Hill, NC, USA
30. Karolinska University Hospital, Stockholm, Sweden
31. State University of New York, Downstate Medical Center, Brooklyn, NY, USA
32. Kantonsspital Schaffhausen, Schaffhausen, Switzerland
33. University of Manitoba Winnipeg, Manitoba, Canada
34. Wake Forest University, Winston-Salem, NC, USA
35. University of Louisville, Louisville, KY, USA
36. Emory University, Atlanta, GA, USA
37. Division of Rheumatology, Department of Internal Medicine, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
38. Medical University of South Carolina, Charleston, SC, USA
39. Landspitali University Hospital, Reykjavik, Iceland
40. University of Texas Health Science Center, San Antonio, TX, USA
41. Cedars-Sinai Medical Center, Los Angeles, CA, USA
42. Department of Epidemiology and Public Health, University of Maryland, Baltimore, MD, USA