[1] Charite Univ Med Berlin, Dept Rheumatol & Clin Immunol, Charite Pl 1, D-10117 Berlin, Germany
[2] Mayo Clin, Coll Med & Sci, Div Rheumatol, Rochester, MN USA
[3] Mayo Clin, Coll Med & Sci, Dept Hlth Sci Res, Rochester, MN USA
[4] Med Univ Graz, Dept Rheumatol, Graz, Austria
[5] Hosp Bruneck, South Tyrolian Hlth Trust, Rheumatol Serv, Brunico, Italy
[6] Southend Univ Hosp, Dept Rheumatol, Chelmsford, Essex, England
[7] Anglia Ruskin Univ, Chelmsford, Essex, England