Editorial
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Mar 7, 2009; 15(9): 1025-1034
Published online Mar 7, 2009. doi: 10.3748/wjg.15.1025
Influence of genes, sex, age and environment on the onset of autoimmune hepatitis
Kathie Béland, Pascal Lapierre, Fernando Alvarez
Kathie Béland, Pascal Lapierre, Fernando Alvarez, Division of Gastroenterology, Hepatology and Nutrition, CHU Sainte-Justine, 3175 Côte Ste-Catherine, Montreal (Quebec) Canada H3T 1C5, Canada
Author contributions: Béland K wrote the paper; Lapierre P and Alvarez F helped writing and revising the paper.
Correspondence to: Fernando Alvarez, MD, Division of Gastroenterology, Hepatology and Nutrition, CHU Sainte-Justine, 3175 Côte Ste-Catherine, Montreal (Quebec) Canada H3T 1C5, Canada. fernando.alvarez@umontreal.ca
Telephone: +1-514-3454626   
Fax: +1-514-3454999
Received: December 26, 2008
Revised: February 8, 2009
Accepted: February 15, 2009
Published online: March 7, 2009
Abstract

The pathogenesis of autoimmune hepatitis (AIH) is complex. However, it is believed that a susceptible individual, owing to his genetic background, sex and age, can develop the disease following exposure to an environmental trigger. Autoimmune hepatitis does not follow a Mendelian pattern of inheritance; hence no single causative genetic locus has been identified. However, several genes, inside and outside the HLA locus, have been linked to an increased susceptibility to AIH. Epidemiological evidence also suggests that the sex and age of the patient plays a role in AIH pathogenesis as the disease onset occurs mainly in the two first decades of life and a higher disease incidence is observed in females. No environmental trigger has been identified, but several have been proposed, mainly viruses and xenobiotics. This article aims at reviewing the current knowledge on susceptibility factors leading to AIH and putative triggers, emphasizing fundamental mechanisms responsible for the break of liver immunological tolerance.

Keywords: Autoimmune hepatitis, Genetic, Enviro-nment, Sex, Virus