1. Department of Laboratory Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
2. Department of Laboratory Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan;
3. Department of Medical Informatics, Yamaguchi University School of Medicine, Ube, Yamaguchi 755-8505, Japan;
4. International Clinical Pathology Center, Setagaya-ku, Tokyo 154-0003, Japan