Conflict of interest

Nobuaki S received honoraria from KMB. HK received research funding from FUJIFILM, Kyowa Kirin, Bristol Myers Squibb, Otsuka, Perseus Proteomics, Daiichi Sankyo, Abbvie, CURED, Astellas Pharma, Chugai, Zenyaku Kogyo, Nippon Shinyaku, Eisai, Takeda, Sumitomo Pharma, and Sanofi, and honoraria from Abbvie, Chugai, Astellas Pharma, and Novartis.TM is member of advisory boards for Takeda, Bayer, Novo Nordisk, Chugai and Pfizer, received honoraria from KMB, The other authors declare no conflict of interest exist that are associated with this manuscript.

Ethical approval

This study, including blood draws (for plasma and serum) and the VWF concentrate infusion test, was approved by the Ethics Review Committee of Nagoya University Graduate School of Medicine (Approval No. 2017–0379).

Informed consent

The patient provided informed consent about this study.