[1] Showa Univ, Dept Med, Div Resp Med & Allergol, Sch Med, Tokyo, Japan
[2] Yamanashi Red Cross Hosp, Dept Med, Div Resp Med, Fujikawaguchiko, Yamanashi, Japan
[3] Kokuho Asahi Chuo Hosp, Dept Med, Div Resp Med, Chiba, Japan
[4] Ebara Hosp, Dept Med, Div Resp Med, Tokyo, Japan
[5] Odawara Municipal Hosp, Dept Med, Div Resp Med, Odawara, Kanagawa, Japan
[6] Showa Univ Fujigaoka Hosp, Dept Med, Div Resp Med, Fujigaoka, Japan