Received: 28 February 2019
Accepted: 14 October 2019
First Online: 29 October 2019
Ethics approval and consent to participate
: All procedures performed in this study involving human participants were conducted with approval of the Suwa Red Cross Hospital ethics committee (reference number: 29–40) in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments. Written informed consent was obtained from all participants for protocols including blood collection, reviewing case records and use of archival sample.
: Not Applicable.
: All of the authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.