1. Figure 4 The gut–liver relationship in PSC
Figure 4 | The gut–liver relationship in PSC. Primary sclerosing cholangitis (PSC) shows a strong clinical association with IBD. The relationship between the concomitant bile duct and bowel affection is not clear, although most hypotheses involve a disturbance of the bowel as the primary affection. In anatomical terms, the disease distribution of PSC follows that of the enterohepatic and cholehepatic circulation of bile acids (terminal ileum, proximal colon, bile ducts). Multiple interactions exist between the gut and the liver throughout this anatomical compartment, for both immunological and metabolic functions. Gut-derived nutrients and other signals, including primary and secondary bile acids, drugs and other xenobiotics, microbial products and antigenic components, are delivered to the liver via the portal circulation. These interactions have led to a series of hypotheses on PSC development which include the homing of gut-derived lymphocytes to the portal areas75, leakage of LPS and other bacterial components into the portal circulation125, and the possible presence of an antigenic trigger derived from the colonic content251. Building from genetic studies, adaptive immune reactions occurring throughout this bidirectional gut–liver axis probably occur, but the specific factor(s) driving these reactions remain to be determined.
Jiang, X. & Karlsen, T. H. (2017) Genetics of primary sclerosing cholangitis and pathophysiological implications
Nat. Rev. Gastroenterol. Hepatol. doi: /nrgastro