[1] Univ Med Ctr Schleswig Holstein, Rheumatol Sect, Clin Internal Med, Kiel, Germany
[2] Lund Univ, Skane Univ Hosp, Nephrol, Lund, Sweden
[3] Univ Pavia, Fdn IRCCS Policlinico S Matteo, Rheumatol, Pavia, Italy
[4] Univ Tubingen, Medius Kliniken, Internal Med, Rheumatol & Immunol, Kirchheim-Teck, Germany
[5] Univ Cambridge, Addenbrookes Hosp, Dept Med, Cambridge, England