Liver fibrosis in biliary atresia.

Biliary atresia (BA) is the most common cholestatic liver disorder requiring liver transplantation in children. Hepatic fibrosis is not only a universal and prominent feature of BA, it is also the most important predictor of outcome following portoenterostomy (PE). Without PE, the progression of hepatic fibrosis is quite dramatic, such that liver cirrhosis is established within a few weeks after birth. Etiologies and molecular networks underpinning such an expeditious fibrogenic process have not been well established. However, immune and nonimmune factors implicated in the pathogenesis of BA, and the resultant cholestasis and oxidative stress, appear to be the main triggers of hepatic fibrosis in BA. Owing to a lack of validated noninvasive tools to monitor liver fibrosis, current prognostic models of BA entail clinical and biochemical variables reflecting liver dysfunction rather than hepatic fibrogenesis. Further work is necessary to validate the results of preliminary studies indicating a good relationship between liver fibrosis determined by transient elastography and other clinical and routinely performed biochemical parameters in pediatric patients. Although a prime candidate for a number of antifibrotic therapies on the horizon, owing to poor understanding of molecular mechanisms, a clear framework of antifibrotic targets has not been outlined in BA. Similarly, specific antifibrotic therapies have not yet been incorporated in clinical practice, limiting these measures to prompt diagnosis and PE operation, prevention and treatment of cholangitis and optimal nutritional support including the administration of fat-soluble vitamins.