Biliary Atresia: pathology, Etiology and Pathogenesis

Abstract

Biliary atresia is a progressive fibrosing obstructive cholangiopathy of the intrahepatic and extrahepatic biliary system, resulting in obstruction of bile flow and neonatal jaundice. Histopathological findings in liver biopsies include the expansion of the portal tracts, with edematous fibroplasia and bile ductular proliferation, with bile plugs in duct lumen. Lobular morphological features may include variable multinucleate giant cells, bilirubinostasis and hemopoiesis. The etiopathogenesis of biliary atresia is multifactorial and multiple pathomechanisms have been proposed. Experimental and clinical studies have suggested that viral infection initiates biliary epithelium destruction and release of antigens that trigger a Th1 immune response, which leads to further injury of the bile duct, resulting in inflammation and obstructive scarring of the biliary tree. It has also been postulated that biliary atresia is caused by a defect in the normal remodelling process. Genetic predisposition has also been proposed as a factor for the development of biliary atresia.

Conjugated Hyperbilirubinemia in Infants: Is There Still a Role for ERCP?

“…Frequency of symptomatic choledochithiasis in patients younger than one year in this cohort is lower than that reported in our older publications, but still relatively high (3.5% versus 7.4%) [ 9 ]. The exact epidemiologic data of choledocholithiasis incidence in neonates and infants are missing, but it can be expected to be far less than 1 in 5000 [ 13 ], and in most cases, it is asymptomatic.…”

“…Some studies have reported the seasonal variation of biliary atresia cases, suggesting a role of viral infections in the etiology of biliary atresia [ 9 ]. We looked at the distribution of the month of birth and the month of diagnosis throughout a year.…”

Biliary Atresia With Extrahepatic Cyst: A Diagnostic Dilemma

“…Liver biopsy plays a crucial role in the diagnostic work-up of infants with neonatal cholestasis, and histopathological examination of portal tracts holds the key findings in diagnosing BA. Duct/ductal bile plugs, fibroblasts proliferation, and a variable amount of inflammatory cells, especially neutrophils, are usually present [ 9 ]. In 5%-10% of infants with biliary atresia, injury to the biliary tree may produce cystic dilation called cystic biliary atresia (CBA) resembling choledochal cyst (CC) [ 9 , 10 ].…”

“…Duct/ductal bile plugs, fibroblasts proliferation, and a variable amount of inflammatory cells, especially neutrophils, are usually present [ 9 ]. In 5%-10% of infants with biliary atresia, injury to the biliary tree may produce cystic dilation called cystic biliary atresia (CBA) resembling choledochal cyst (CC) [ 9 , 10 ]. CBA and CC are distinct entities histologically but may occasionally overlap.…”

Association of Gut Microbiota and Metabolites With Disease Progression in Children With Biliary Atresia

“…Experimental and clinical studies have shown that viral infection triggers the destruction of the biliary epithelium and release of antigens, which trigger the Th1 immune response, release proinflammatory cytokines, and further damage the bile ducts. Infection by cytomegalovirus (CMV), rhinovirus, human herpes virus, human papillomavirus, adenovirus, Epstein–Barr virus (EBV), hepatitis B virus, parvovirus B19, and rotavirus in the liver and hepatobiliary tree may be associated with the occurrence of biliary atresia and other infantile obstructive cholangiopathies ( 12 ). Besides, previous research demonstrated that cholestasis, the accumulation of bile acids in the liver, fails to promote liver injury in the absence of the microbiome in vivo ( 13 ).…”