Title:Update on Etiology and Pathogenesis of Biliary Atresia
Volume: 19
Issue: 1
Author(s): Patrícia Quelhas, Carlos Cerski and Jorge Luiz dos Santos*
Affiliation:
- CICS-UBI - Centro de Investigação em Ciências da Saúde, University of Beira Interior, 6200-506 Covilhã, Portugal
Keywords:
Biliary atresia, hypoxia, ischemia, etiology, genetics, epigenetics, gut microbiota, immunity.
Abstract: Biliary atresia is a rare inflammatory sclerosing obstructive cholangiopathy that initiates
in infancy as complete choledochal blockage and progresses to the involvement of intrahepatic biliary
epithelium. Growing evidence shows that biliary atresia is not a single entity with a single etiology
but a phenotype resulting from multifactorial events whose common path is obliterative cholangiopathy.
The etiology of biliary atresia has been explained as resulting from genetic variants,
toxins, viral infection, chronic inflammation or bile duct lesions mediated by autoimmunity, abnormalities
in the development of the bile ducts, and defects in embryogenesis, abnormal fetal or prenatal
circulation and susceptibility factors. It is increasingly evident that the genetic and epigenetic
predisposition combined with the environmental factors to which the mother is exposed are potential
triggers for biliary atresia. There is also an indication that a progressive thickening of the arterial
middle layer occurs in this disease, suggestive of vascular remodeling and disappearance of the interlobular
bile ducts. It is suggested that the hypoxia/ischemia process can affect portal structures in
biliary atresia and is associated with both the extent of biliary proliferation and the thickening of the
medial layer.
