Primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD): a condition exemplifying the crosstalk of the gut–liver axis

Abstract

The close relationship between primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) provides a good opportunity to comprehend the gut–liver axis. The gut and the liver have reciprocal interactions, including how gut inflammation influences the liver through immune cells and the microbiota and how the microbiota in the gut modifies bile acids, which are produced and secreted from the liver. PSC-IBD shows distinct clinical findings from classical IBD. In addition, a distinct genetic predisposition and unique microbiota composition suggest that PSC-IBD is an independent disease entity. Understanding the pathogenesis of PSC-IBD helps to develop novel and effective therapeutic agents. Given the high risk of malignancies associated with PSC-IBD, it is critical to identify patients at high risk and implement appropriate surveillance and monitoring strategies. In this review, we provide an overview of PSC-IBD, which exemplifies the gut–liver axis.

Gut-liver interaction: Inflammatory bowel disease and liver disease a distinct condition

Inflammatory bowel disease (IBD) combined with a rare liver disorder should be classed as a separate health condition, with researchers in the USA calling for extensive research. Patients with IBD and primary sclerosing cholangitis (PSC), a severe liver condition involving the inflammation, scarring and eventual blocking of bile ducts, frequently suffer serious complications, including cancer. However, the pathogenesis of PSC-IBD is unclear. Sungjin Ko and colleagues at the University of Pittsburgh, USA, reviewed PSC-IBD and point out that the condition has clinical characteristics distinguishing it from IBD. PSC-IBD involves disruption to both innate and adaptive immunity, and genetic and environmental components contribute to disease risk. Further research is needed into the extensive interactions between gut microbiota and liver bile acids. PSC-IBD patients should be screened regularly to detect associated cancers early.