1. Department of Rheumatology and Clinical Immunology, Charité–University Medicine Berlin, Berlin, Germany
2. Division of Rheumatology and Department of Health Sciences Research, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
3. Department of Rheumatology, Medical University Graz, Graz, Austria
4. Rheumatology Service, South Tyrolian Health Trust, Hospital Bruneck, Bruneck, Italy
5. Department of Rheumatology, Southend University Hospital and Anglia Ruskin University, Essex, UK