1. Section of Rheumatology, Center for Research and Development, Uppsala University/Region of Gävleborg, Gävle, Sweden
2. Section of Clinical Chemistry, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
3. Section of Rheumatology, Department of Clinical Sciences, Lund University, Lund, Sweden
4. Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
5. Clinic of Rheumatology, Falun Hospital, Falun, Sweden
6. Section of Rheumatology, Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden