[1] Toho Univ, Sch Med, Dept Internal Med 1, Tokyo, Japan
[2] Fujita Hlth Univ, Sch Med, Dept Internal Med, Toyoake, Aichi 47011, Japan
[3] Chiba Canc Ctr Hosp, Div Hematol Oncol, Chiba, Japan
[4] Toyama Prefectural Cent Hosp, Toyama, Japan
[5] Niigata Univ, Sch Med, Dept Internal Med 1, Niigata, Japan