[1] Martina Hansens Hosp, Dept Rheumatol, Baerum, Norway
[2] Hosp Rheumat Dis, Dept Rheumatol, Haugesund, Norway
[3] Univ Hosp Northern Norway, Dept Rheumatol, Tromso, Norway
[4] St Olavs Univ Hosp, Dept Rheumatol, Trondheim, Norway
[5] Hosp Southern Norway, Dept Res, Kristiansand, Norway
[6] Akershus Univ Hosp, Dept Infect Dis, Div Internal Med, Lorenskog, Norway