[1] Hokkaido Univ, Fac Med, Dept Rheumatol Endocrinol & Nephrol, Sapporo, Hokkaido, Japan
[2] Hokkaido Univ, Grad Sch Med, Sapporo, Hokkaido, Japan
[3] Keio Univ, Div Rheumatol, Dept Internal Med, Sch Med, Tokyo, Japan
[4] Chugai Pharmaceut Co Ltd, Tokyo, Japan
[5] Nippon Shinyaku Co Ltd, Tokyo, Japan
[6] Fujita Hlth Univ, Dept Nephrol, Sch Med, Toyoake, Aichi, Japan