1. Division of Immunology, Stanford University, San Francisco, CA, USA
2. Centre for Prognosis Studies in The Rheumatic Diseases, The Toronto Hospital, Toronto, Ontario, Canada
3. Center for Rheumatology, Department of Medicine, University College London, London, UK
4. Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
5. 2nd Department of Medicine Krankenhaus Lainz, Vienna, Austria
6. Department of Medicine, University of Ottawa, Ottawa, Canada