Text and Data Mining valid from 2018-04-21
Received: 26 September 2017
Revised: 9 February 2018
Accepted: 4 April 2018
First Online: 21 April 2018
Compliance with ethical standards
: This work was supported by a grant for medical research from Tokyo Metropolitan Government. Author Norio Sugaya has received lecture fees from Astellas, Daiichi Sankyo, Denka Seiken, and Takeda, but none of these talks were connected with the work presented here. Author Masayoshi Shinjoh has also received lecture fees from Japan Vaccine and MSD, but again, the talks were unconnected with the studies describe in this paper. No other authors declare any potential conflicts of interest.
: Informed consent was obtained from all individual participants included in the study.