1. Department of Transfusion Nagano Red Cross Hospital Nagano Japan
2. Department of Internal Medicine School of Dentistry Health Sciences University of Hokkaido Ishikari‐Tobetsu Japan
3. Department of Clinical Laboratory Hospital of Health Sciences University of Hokkaido Sapporo Japan
4. Department of Clinical Laboratory Health Sciences University of Hokkaido Ishikari‐Tobetsu Japan
5. Department of Hematology Nagano Red Cross Hospital Nagano Japan
6. Department of Biomedical Laboratory Sciences School of Health Sciences Shinshu University School of Medicine Matsumoto Japan