Ângelo Zambam de Mattos1, Angelo Alves de Mattos2. 1. Gastroenterology and Hepatology Unit - Pontifical Catholic University of Rio Grande do Sul, Brazil; Gastroenterology and Hepatology Unit - Irmandade Santa Casa de Misericórdia de Porto Alegre, Brazil. Electronic address: angmattos@hotmail.com. 2. Post-Graduation Course of Hepatology - Federal University of Health Sciences of Porto Alegre, Brazil; Gastroenterology and Hepatology Unit - Irmandade Santa Casa de Misericórdia de Porto Alegre, Brazil.