Received: 3 September 2021
Accepted: 3 December 2021
First Online: 9 December 2021
: The authors declare no competing interests.
: This retrospective, observational study protocol was approved by the institutional review board of Chiba University (approval number 2584). The exploratory analysis of plasma cytokines was also approved by the institutional review board of Chiba University (approval number 826) and written informed consent was obtained from all the participants.
: Not applicable.
: The authors declare that they have no competing interests.