[Immunopathogenesis and therapy of primary sclerosing cholangitis]

Primary sclerosing cholangitis (PSC) is an immune-mediated disease of the biliary tract for which no prognosis-improving therapies are yet available. PSC is characterized by genetic risk factors, alterations in the microbiome and pathological immune activation leading to the development of biliary fibrosis. Cholangiocytes play an active role in the inflammatory processes, as they interact directly with the microbiome and immune cells. The concomitant chronic inflammatory bowel disease has a distinct phenotype and causes a reciprocal modulation of intestinal and hepatic disease activity via changes in the intestinal barrier and the enterohepatic circulation of bile acids. While the currently available drugs and endoscopic treatment options are only symptomatically effective, new pharmacologic therapies are under clinical evaluation. In this review, we aim to provide an insight into the current understanding of the pathogenesis of PSC and new therapeutic developments.