Received: 3 April 2020
Accepted: 29 May 2020
First Online: 26 June 2020
Ethics approval and consent to participate
: The study was approved by the by the local ethics committee at the University Hospital in Linköping (Ref. No. 2013/403–31, P. Zsigmond), and informed written consent was received from the patients and healthy controls.
: The authors of this article declare no competing interests.