[1] Nippon Med Sch, Grad Sch Med, Tokyo, Japan
[2] Univ Occupat & Environm Hlth, Kitakyushu, Fukuoka, Japan
[3] Teikyo Univ, Sch Med, Dept Internal Med, Tokyo, Japan
[4] Tokyo Metropolitan Tama Med Ctr, Dept Rheumatol, Tokyo, Japan
[5] St Lukes Int Hosp, Immunorheumatol Ctr, Tokyo, Japan
[6] Celgene Corp, Summit, NJ USA
[7] Kagawa Univ, Internal Med Div Hematol Rheumatol & Resp Med, Takamatsu, Kagawa, Japan