1 Division of Rheumatology, Department of Medicine III, University Medical Center and Faculty of Medicine Carl Gustav Carus, TU Dresden, Dresden, Germany martin.aringer@uniklinikum-dresden.de.
2 Division of Rheumatology and Immunology, Department of Medicine, Brigham and Womens Hospital, Harvard Medical School, Boston, Massachusetts, USA.
3 Department of Rheumatology and Clinical Immunology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
4 Division of Rheumatology, Department of Medicine, Toronto Western Hospital, University Health Network, Mount Sinai Hospital, and Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.