1 Department of Gastroenterology and Digestive Endoscopy, S. Giovanni Addolorata Hospital, Via Dell' Amba Aradam 9, Rome, 00184 Italy. Electronic address: cpagnini@hsangiovanni.roma.it.
2 Department of Gastroenterology and Digestive Endoscopy, S. Giovanni Addolorata Hospital, Via Dell' Amba Aradam 9, Rome, 00184 Italy.
3 Department of Pathology and Laboratory Medicine, S. Giovanni Addolorata Hospital, Via Dell' Amba Aradam 9, Rome, 00184, Italy.