1. Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, Bergen, Norway,
2. Department of Pathology, Haukeland University Hospital, Bergen, Norway,
3. Department of Oral Surgery and Oral Medicine, University of Oslo, Oslo, Norway,
4. Broegelmann Research Laboratory, Department of Clinical Science, University of Bergen, Bergen, Norway, and
5. Department of Rheumatology, Haukeland University Hospital, Bergen, Norway