Primary sclerosing cholangitis and inflammatory bowel disease comorbidity: an update of the evidence Original paper

What was studied?

This review article focuses on the comorbidity of primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD), specifically ulcerative colitis (UC) and Crohn’s disease (CD). It provides an update on the current evidence surrounding this association. PSC-IBD is a unique disease phenotype that poses a significant challenge in clinical management. The article delves into the pathogenetic mechanisms underlying this comorbidity, including genetic predispositions, immune dysregulation, and the role of microbiota. It also highlights the distinct clinical characteristics of IBD in patients with PSC, noting differences in disease presentation and severity compared to IBD patients without PSC. The increased risk of colorectal cancer (CRC) and hepatobiliary malignancies in PSC-IBD patients is discussed, alongside the current approaches to screening and management.

Who was studied?

The review consolidates data from various studies involving patients diagnosed with both PSC and IBD. While the study doesn’t involve new patient cohorts, it summarizes findings from cohort studies, meta-analyses, and population-based studies, primarily from North America, Europe, and some parts of Asia. The patients studied typically have PSC associated with UC, though a smaller proportion has PSC with CD. The research on PSC-IBD includes both adults and pediatric populations, with an emphasis on the different clinical outcomes seen in these groups. The studies also assess the risk of malignancies such as CRC, cholangiocarcinoma (CCA), and gallbladder carcinoma (GBC), and the impact of IBD severity on the progression of PSC.

Most important findings

The review confirms that patients with PSC have a significantly higher incidence of IBD, particularly UC, compared to the general population. The data suggest that approximately 60-80% of PSC patients also have IBD, with UC being the most common form of IBD in these individuals. Interestingly, the clinical presentation of IBD in PSC patients is typically milder than in IBD alone. For example, PSC-IBD patients often exhibit pancolitis with a right-to-left intestinal inflammatory gradient, with rectal sparing and backwash ileitis being common features. However, despite this relatively quiescent clinical course, these patients are at a higher risk for developing CRC and other hepatobiliary malignancies, such as CCA and GBC. The review also emphasizes the importance of vigilant screening for these malignancies in PSC-IBD patients, suggesting annual colonoscopies and liver function tests.

Key implications

The findings have significant implications for the management of PSC-IBD patients. Clinicians should be aware of the unique clinical phenotype of PSC-IBD, which may present with less severe symptoms despite extensive colitis. These patients require close monitoring, especially given their increased risk of malignancy. Surveillance for CRC, CCA, and GBC should be a priority, with regular screening intervals recommended based on disease severity and the presence of risk factors such as age and comorbidities. The review underscores the need for personalized treatment approaches, as the management of PSC-IBD differs from that of PSC or IBD alone. Additionally, the potential role of microbiota dysbiosis in disease progression highlights the need for further research into microbiome-based therapies. Finally, the review calls for more robust clinical trials and research to establish evidence-based guidelines for the management and screening of PSC-IBD patients, particularly focusing on the relationship between IBD severity and PSC progression.