1. Department of Medical Biology; UiT-the Arctic University of Norway; Tromsø Norway
2. Department of Rheumatology; OUH-Oslo University Hospital; Oslo Norway
3. Nephrological Unit, Fondazione Ca' Granda IRCCS; Ospedale Maggiore; Milano Italy
4. Department of Clinical Medicine; UiT-the Arctic University of Norway; Tromsø Norway
5. Department of Medicine; OUH-Oslo University Hospital; Oslo Norway
6. Department of Pathology; OUH-Oslo University Hospital; Oslo Norway
7. Department of Rheumatology; University Hospital of North Norway; Tromsø Norway
8. Department of Clinical Sciences and Community Health; University of Milan and IRCCS, Istituto Auxologico Italiano; Milan Italy