1. Department of Hematology Tokushima Prefecture Central Hospital Tokushima Japan
2. Department of Hematology Tokushima Prefecture Miyoshi Hospital Miyoshi Japan
3. Department of Neurosurgery Tokushima Prefecture Miyoshi Hospital Miyoshi Japan
4. Department of Molecular Patho‐Biochemistry and Patho‐Biology Yamagata University School of Medicine Yamagata Japan
5. The Japanese Collaborative Research Group (JCRG) on Autoimmune Acquired Coagulation Factor Deficiencies Yamagata Japan