Funding for this research was provided by:
Gerhard Domagk Scholarship
Received: 9 July 2019
Accepted: 24 October 2019
First Online: 28 November 2019
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee of the Medical Faculty, University of Greifswald (registration code B133/12). All parents and adult donors provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.