Biliary atresia

Biliary atresia, also known as extrahepatic ductopenia and progressive obliterative cholangiopathy, is a childhood disease of the liver in which one or more bile ducts are abnormally narrow, blocked, or absent. It can be congenital or acquired. As a birth defect in newborn infants, it has an incidence of one in 10,000–15,000 live births in the United States, and a prevalence of one in 16,700 in the British Isles. Biliary atresia is most common in East Asia, with a frequency of one in 5,000. Biliary atresia, also known as extrahepatic ductopenia and progressive obliterative cholangiopathy, is a childhood disease of the liver in which one or more bile ducts are abnormally narrow, blocked, or absent. It can be congenital or acquired. As a birth defect in newborn infants, it has an incidence of one in 10,000–15,000 live births in the United States, and a prevalence of one in 16,700 in the British Isles. Biliary atresia is most common in East Asia, with a frequency of one in 5,000. The cause of biliary atresia in Egyptian infants has been proved to be result of aflatoxin induced cholangiopathy acquired prenatally in infants who have glutathione S transferase M1 deficiency. Congenital biliary atresia has been associated with certain genes, while acquired biliary atresia is thought to be a result of an autoimmune inflammatory response, possibly due to a viral infection of the liver soon after birth. The only effective treatments are surgeries such as the Kasai procedure and liver transplantation. Initially, the symptoms of biliary atresia are indistinguishable from those of neonatal jaundice, a usually harmless condition commonly seen in infants. Distinctive symptoms of biliary atresia are usually evident between one and six weeks after birth. Infants and children with biliary atresia develop progressive cholestasis, a condition in which bile is unable to leave the liver and builds up inside of it. When the liver is unable to excrete bilirubin through the bile ducts in the form of bile, bilirubin begins to accumulate in the blood, causing symptoms. These symptoms include yellowing of the skin, itchiness, poor absorption of nutrients (causing delays in growth), pale stools, dark urine, and a swollen abdomen. Eventually, cirrhosis with portal hypertension will develop. If left untreated, biliary atresia can lead to liver failure. Unlike other forms of jaundice, however, biliary-atresia-related cholestasis mostly does not result in kernicterus, a form of brain damage resulting from liver dysfunction. This is because in biliary atresia, the liver, although diseased, is still able to conjugate bilirubin, and conjugated bilirubin is unable to cross the blood–brain barrier.