Clinical implications of novel aspects of biliary pathophysiology.

Cholangiocytes are the epithelial cells that line the biliary tree; they are the target of chronic diseases termed cholangiopathies, which represent a daily challenge for clinicians, since definitive medical treatments are not available yet. It is generally accepted that the progression of injury in the course of cholangiopathies, and promotion and progression of cholangiocarcinoma are at least in part due to the failure of the cholangiocytes' mechanisms of adaptation to injury. Recently, several studies on the pathophysiology of the biliary epithelium have shed some light on the mechanisms that govern cholangiocyte response to injury. These studies provide novel information to help interpret some of the clinical aspects of cholangiopathies and cholangiocarcinoma; the purpose of this review is thus to describe some of these novel findings, focusing on their significance from a clinical perspective.