1. Department of Endoscopy and Hepatogastroenterology, Pavillon L, Edouard Herriot Hospital, Lyon, France
2. Institute of Pathology Est, Hospices Civils de Lyon, Lyon, France
3. EnCoV, Institut Pascal, UMR 6602, CNRS/UCA/SIGMA, EnCoV, Clermont-Ferrand, France
4. Department of Endoscopy and Hepatogastroenterology, Amiens University Hospital, Amiens, France