Biliary atresia causes

There have been many theories about etiopathogenesis such as Reovirus 3 infection, congenital malformation, congenital CMV infection, autoimmune theory. This means that the etiology and pathogenesis of biliary atresia are largely unknown.

Biliary atresia does not have a clear identified cause. It was previously thought to be idiopathic, a destructive inflammatory process leaving fibrotic remnants at the porta hepatis. It is now thought it may be secondary to viral infections or an autoimmune-induced injury in some cases. The viruses thought to be involved are:

• Reovirus,
• Rotavirus,
• Cytomegalovirus (CMV)^[1][2]
  • The highest association of a viral infection with biliary atresia is with CMV. There may be an inability to identify the virus because of a short timeframe to detect it, which leads to uncertainty in association. The viral infection of cholangiocytes may predispose to an aberrant autoimmune response, cascading to progressive biliary injury and cirrhosis.

Through a genome-wide study, an association between biliary atresia and the ADD3 gene was detected in Chinese populations and confirmed in Thai populations. Anther possible association with the deletion of the GPC1 gene has been reported, which encodes a glypican 1-a heparan sulfate proteoglycan.^{[3] [4]}

Aflatoxin B1 exposure, and to a lesser extent aflatoxin B2 exposure during late pregnancy may cause biliary atresia. Maternal detoxification ability protects the fetus during intrauterine life, but it struggles with the aflatoxin in its blood and liver after birth, causing cholangitis in the baby. ^[5]