[1] Univ Hosp Schleswig Holstein, Dept Rheumatol, Campus Lubeck, Lubeck, Germany
[2] Charite, Rheumatol & Clin Immunol, Berlin, Germany
[3] Charite Univ Med Berlin, Rheumatol & Clin Immunol, Berlin, Germany
[4] Charite Univ Med Berlin, Dept Rheumatol, Berlin, Germany
[5] Charite Univ Med Berlin, Dept Nephrol, Berlin, Germany
[6] Charite, Berlin, Germany
[7] Deutsch Rheumaforschungszentrum, Berlin, Germany
[8] Univ Klinikum Schleswig Holstein, Dept Rheumatol, Lubeck, Germany