[1] Univ Verona, Rheumatol Unit, Pz Scuro 10, I-37135 Verona, Italy
[2] Univ Alabama Birmingham, Div Clin Immunol & Rheumatol, Birmingham, AL 35294 USA
[3] Univ Lyon, Hop E Herriot, INSERM UMR 1033, Lyon, France
[4] Univ Barcelona, Hosp Clin, Rheumatol Dept, CIBERehd,IDIBAPS, Barcelona, Spain
[5] Southern Hosp Trust, Div Rheumatol, Med Dept, Trondheim, Norway
[6] Locat VUmc, Amsterdam UMC, Amsterdam, Netherlands
[7] Univ Novi Sad, Fac Med, Novi Sad, Serbia
[8] Clin Ctr Vojvodina, Clin Orthoped Surg, Novi Sad, Serbia
[9] Northern Gen Hosp, Metab Bone Ctr, Sheffield, S Yorkshire, England
[10] Charite Univ Med Berlin, Dept Gastroenterol Infect Dis & Rheumatol, Berlin, Germany
[11] German Rheumatism Res Ctr, Epidemiol Unit, Berlin, Germany
[12] Maastricht Univ, CAPHRI Sch Publ Hlth & Primary Care, Maastricht, Netherlands
[13] Hasselt Univ, Biomed Res Ctr, Agoralaan, Diepenbeek, Belgium