title: Extrahepatic biliary atresia: current concepts and future directions.
abstract: OBJECTIVE
  To provide an updated review on extrahepatic biliary atresia, focusing mainly on its etiopathogenesis, diagnosis, treatment and prognosis.
  
  
  METHODS
  MEDLINE and PubMed databases were searched using the following keywords: biliary atresia, etiopathogenesis, diagnosis, treatment, prognosis, children.
  
  
  RESULTS
  Extrahepatic biliary atresia is the main indication for liver transplantation among pediatric patients. As to its etiology, cytomegalovirus, reovirus and rotavirus have been widely investigated as possible triggers of the immunomediated obstruction of the biliary tree. The immune response, especially the predominant TH1 and interferon-gamma responses, genetic susceptibility and disorders related to the embryonic development of the biliary tree can play a role in the etiopathogenesis of extrahepatic biliary atresia. Yet today, portoenterostomy is the only available treatment, with better results when performed in the first 2 months of life. As to prognosis, all untreated children eventually die due to complications resulting from portal hypertension and liver cirrhosis, and most treated children have to undergo liver transplantation.
  
  
  CONCLUSIONS
  Extrahepatic biliary atresia is still the major indication for pediatric liver transplantation, and to change this scenario some more light should be shed upon the etiopathogenesis of biliary atresia in different disease phenotypes. Future research into the role of interferon-gamma and of other cytokines is necessary in order to assess whether these aspects should be potential targets for therapeutic intervention.
authors.affiliation: Universidade de Brasília, Brasília, DF, Brazil. elisacarvalho@terra.com.br
authors.forename: Elisa
authors.initials: E
authors.lastname: de Carvalho
authors.forename: Cláudia Alexandra Pontes
authors.initials: CA
authors.lastname: Ivantes
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Bezerra
mesh_terms: D001656:Biliary Atresia / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D002648:Child; D005544:Forecasting; D006801:Humans; D016031:Liver Transplantation; D011171:Portoenterostomy, Hepatic; D011379:Prognosis