1 Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, 30-1 Oyaguchikamicho, Itabashi-ku, 173-8610, Tokyo, Japan. tsuchida.sachio@nihon-u.ac.jp.
2 Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, 30-1 Oyaguchikamicho, Itabashi-ku, 173-8610, Tokyo, Japan. nakayama.tomohiro@nihon-u.ac.jp.