Intrabiliary rapamycin may slow progression of primary sclerosing cholangitis

Primary sclerosing cholangitis

Primary sclerosing cholangitis is a rare, chronic cholestatic liver disease characterised by intrahepatic or extrahepatic stricturing, or both, with bile duct fibrosis. Inflammation and fibrosis of bile ducts and the liver are followed by impaired bile formation or flow and progressive liver dysfunction. Patients might be asymptomatic at presentation or might have pruritus, fatigue, right upper quadrant pain, recurrent cholangitis, or sequelae of portal hypertension. The key diagnostic elements are cholestatic liver biochemistry and bile duct stricturing on cholangiography. Genetic and environmental factors are important in the cause of the disease, with the intestinal microbiome increasingly thought to play a pathogenetic role. Approximately 70% of patients have concurrent inflammatory bowel disease and patients require colonoscopic screening and surveillance. Primary sclerosing cholangitis is associated with increased malignancy risk and surveillance strategies for early cholangiocarcinoma detection are limited. No single drug has been proven to improve transplant-free survival. Liver transplantation is effective for advanced disease but at least 25% of patients develop recurrent disease in the graft.

Primary sclerosing cholangitis

Primary sclerosing cholangitis is the classic hepatobiliary manifestation of inflammatory bowel disease and is generally chronic and progressive. Patients frequently present with asymptomatic, anicteric cholestasis, but many develop progressive biliary strictures with time, leading to recurrent cholangitis, biliary cirrhosis, and end-stage liver disease. Medical treatment does not slow the progression of disease, and many patients need liver transplantation, after which recurrent disease is a risk. The increased incidence of hepatobiliary cancer, which is not related to the underlying severity of biliary fibrosis, is of particular concern. Risk of colorectal cancer is also increased in patients with coexistent inflammatory bowel disease. Mechanistic insights have arisen from studies of secondary sclerosing cholangitis, in which a similar clinical profile is associated with a specific cause, and genomic studies have elucidated potential disease-initiating pathways in the primary form. The close association between inflammatory bowel disease and primary sclerosing cholangitis underscores the need to further understand the role of environmental factors in generation of lymphocytes that are postulated to be retargeted, deleteriously, to the biliary tree. Treatment of primary sclerosing cholangitis is confined to supportive measures, but advances in pathobiology suggest that new stratified approaches will soon be available.

Advances in research of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic autoimmune liver disease characterized by diffuse inflammation, concentric fibrosis, focal or segmental stricture of intrahepatic and/or extrahepatic bile ducts, which can eventually lead to cirrhosis or hepatic function failure. The pathogenesis of PSC may involve genetic susceptibility, innate or adaptive immunity, and Epstein-Barr virus infection. Diagnostic imaging modalities include endoscopic retrograde cholangiography, magnetic resonance cholangiopancreatography, and high-resolution three-dimensional SPGR. Proteomic analysis of bile and urine may become a new tool for early diagnosis of cholangiocarcinoma in PSC patients. Ursodeoxycholic acid (UDCA), endoscopic therapy and liver transplantation are major treatments for PSC.