1 a Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine , 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
2 b Division of Rheumatology, Department of Internal Medicine, Tokai University School of Medicine , Isehara, Kanagawa 259-1193, Japan.
3 c Hakone National Hospital , Kazamatsuri 412, Odawara, Kanagawa 250-0032, Japan.