[1] Oslo Univ Hosp, Dept Med Biochem, Oslo, Norway
[2] Univ Oslo, Fac Dent, Dept Oral Biol, Oslo, Norway
[3] Allegheny Hlth Network, Lupus Ctr Excellence, Med, Pittsburgh, PA USA
[4] Betanien Hosp, Rheumatol, Skien, Norway
[5] Lillehammer Hosp Rheumat Dis, Lillehammer, Norway
[6] Feiring Heart Clin, Dept Cardiac Surg, Feiring, Norway
[7] Oslo Univ Hosp, Dept Cardiothorac Surg, Oslo, Norway
[8] Oslo Univ Hosp, Dept Biostat, Oslo, Norway
[9] Brigham & Womens Hosp, Dept Rheumatol, Boston, MA 02115 USA