Department of Respiratory Medicine, Hamamatsu Medical Center, 328 Tomitsuka, Hamamatsu, Shizuoka 432-8580, Japan. Electronic address: shikatarawasagao@gmail.com. Department of Respiratory Medicine, Hamamatsu Medical Center, 328 Tomitsuka, Hamamatsu, Shizuoka 432-8580, Japan; Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan. Department of Respiratory Medicine, Hamamatsu Medical Center, 328 Tomitsuka, Hamamatsu, Shizuoka 432-8580, Japan.