[1] Univ Palermo, Gastroenterol Unit, Palermo, Italy
[2] Osped S Camillo Roma, Rome, Italy
[3] AO Ordine Mauriziano, Rome, Italy
[4] Catholic Univ, Internal Med & Gastroenterol Unit, Rome, Italy
[5] Univ Padua, Padua, Italy
[6] Osped IRCCS Casa Sollievo della Sofferenza, San G Rotondo, Italy
[7] Univ Roma La Sapienza, Rome, Italy
[8] Univ Roma Tor Vergata, Rome, Italy
[9] Univ Bologna, Policlin S Orsola, Bologna, Italy
[10] Osped L Sacco, Milan, Italy
[11] Osped S Filippo Neri, Rome, Italy
[12] Policlin Univ, Messina, Italy
[13] Ist Clin Humanitas, Rozzano, Italy
[14] Univ Naples 2, Naples, Italy
[15] Univ Naples Federico II, Naples, Italy