[1] Med Univ Graz, Clin Dept Rheumatol & Immunol, Graz, Austria
[2] Univ Manchester, Fac Biol Med & Hlth, Ctr Epidemiol Versus Arthrit, Sch Biol Sci,Div Musculoskeletal & Dermatol Sci, Manchester, England
[3] Kings Coll London, Ctr Rheumat Dis, London, England
[4] Kings Coll Hosp London, Rheumatol Dept, London, England