1. Department of Hematology, Sasebo City General Hospital, Sasebo, Japan;
2. Department of Hematology, Atomic Bomb Disease and Hibakusya Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan;
3. School of Health Sciences, University of the Ryukyus, Nishihara, Japan;
4. Department of Internal Medicine, National Hospital Organization Nagasaki Medical Center, Ohmura, Japan;
5. Department of Internal Medicine, Nagasaki Rousai Hospital, Sasebo, Japan; and
6. Department of Hematology, National Kyushu Cancer Center, Fukuoka, Japan