Prevalence of inflammatory bowel disease in patients with primary sclerosing cholangitis: A systematic review and meta-analysis

Background and Aim Previous studies have established an association between primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis (UC). The disease burden of IBD in PSC patients was not well estimated. The study aimed to quantify the pooled prevalence of IBD in PSC and to investigate whether subtypes of PSC and sex influence the prevalence of IBD. Methods PubMed, Embase, and Web of Science were searched through November 2021 for studies reporting data on IBD among PSC patients. The outcomes were the prevalence of IBD in patients with PSC, as well as the association (odds ratio [OR]) of IBD in PSC according to subtype and sex. Results Based on the analysis of 25 studies, the prevalence of IBD in patients with PSC was 71.1% (95% CI 68.2-75.1%), most commonly in UC (55.9%, 95% CI 52.5-59.3%). The pooled prevalence of IBD was 76.9% in Australia (95% CI 71.2-82.6%, 1 study), 75.9% (95% CI 69.5-82.3%, 4 studies) in North America, 70.9% (95% CI 65.8-76.0%, 17 studies) in Europe and 67.0% (95% CI 57.9-76.0%, 2 studies) in Asia. Male PSC patients had a higher prevalence of IBD (OR 1.67, 95% CI 1.52-1.83) and UC (OR 2.02, 95% CI 1.56-2.63) and a lower prevalence of CD (OR 0.77, 95% CI 0.67-0.88) than female patients. Large duct PSC patients had a higher prevalence of IBD (OR 2.57, 95% CI 2.03-3.25) and UC (OR 4.51, 95% CI 1.22-16.71) than small duct PSC patients. Conclusions The study provided the first pooled estimates of the burden of IBD in patients with PSC and could be used as the basis for risk stratification of PSC patients.