[1] Hosp Southern Norway, Dept Res, Kristiansand, Norway
[2] Oslo Univ Hosp, Rikshosp, Dept Rheumatol, Oslo, Norway
[3] Akershus Univ Hosp, Dept Infect Dis, Div Internal Med, Lorenskog, Norway
[4] Haugesund Hosp Rheumat Dis, Dept Rheumatol, Haugesund, Norway
[5] Hosp Finnmark, Dept Med, Kirkenes, Norway
[6] UiT Arctic Univ Norway, Inst Clin Med, Tromso, Norway