The Epigenetics of Primary Biliary Cholangitis

Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune liver disease characterized by biliary destruction, progressive cholestasis, and eventually end-stage liver disease. Patients develop a well-orchestrated immune reaction against mitochondrial antigens that specifically targets intrahepatic biliary cells; however, the exact pathogenesis of the disease remains unclear. Genetic susceptibility defines the underlying propensity to develop PBC; environmental factors are external triggers that exert their effects in genetically susceptible individuals. Therefore different polymorphisms and epigenetic modifications play a crucial role in the pathogenesis of PBC. This chapter aims to review recent studies of epigenetic abnormalities in PBC. Dysregulation affecting immune cells and cholangiocytes, which are known to be involved in the pathogenesis of PBC, will also be discussed. Epigenetic mechanisms that have so far not been identified in PBC will be also be reviewed.