1. Department of Epidemiology and Pre-Clinical Research; National Institute for Infectious Diseases “L. Spallanzani”; Rome Italy
2. Multivisceral Transplant Unit; Department of Surgery, Oncology and Gastroenterology; Padua University Hospital; Padua Italy
3. Liver and Multiorgan Transplant Unit; S. Orsola-Malpighi University Hospital; Bologna Italy
4. Liver Transplant Unit; Department of Medical and Biological Sciences; University of Udine; Udine Italy
5. Division of General Surgery and Liver Transplantation; S. Camillo Hospital; Rome Italy
6. Department of Gastroenterology and Hepatology; Istituto Mediterraneo per i Trapianti e Terapie ad Alta Specializzazione (ISMETT); University of Pittsburgh Medical Center; Palermo Italy
7. Department of Emergency and Organ Transplantation; Section of Gastroenterology; University Hospital; Bari Italy
8. Department of General Surgery and Organ Transplantation; Umberto I Policlinic; Sapienza University; Rome Italy
9. UOC Transplant Unit; Department of Surgery; Tor Vergata University; Rome Italy
10. Department of Surgery, General and Hepatic Transplantation Surgery Unit; A.O.B. Brotzu; Cagliari Italy
11. Epidemiology and Biostatistics Unit; Centro di Riferimento Oncologico IRCCS; Aviano Pordenone Italy