Prevalence of Primary Sclerosing Cholangitis in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-analysis.

Although the association between inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC) is well recognised, uncertainties remain about the magnitude of this problem. We conducted a systematic review and meta-analysis assessing prevalence of PSC in IBD to investigate whether type of IBD, how presence of PSC was defined, sex, disease extent or location, time period, or geographical location influenced prevalence.<h4>Methods</h4>MEDLINE, EMBASE, and EMBASE Classic were searched (from inception to 10^th April 2021) to identify observational studies recruiting ≥50 adult patients with IBD reporting prevalence of PSC. Data were extracted, and pooled prevalence, odds ratios (OR), and 95% confidence intervals (CIs) calculated.<h4>Results</h4>Of 1204 citations, 64 studies were eligible, containing 776,700 patients. Overall, pooled prevalence of PSC in IBD was 2.16%, and was highest in South America and lowest in Southeast Asia. Pooled prevalence in patients with UC, CD, or IBD-U was 2.47%, 0.96% and 5.01%, respectively. Pooled prevalence was significantly higher in UC versus CD (OR = 1.69; 95% CI 1.24-2.29). In subgroup analyses according to method used to define presence of PSC, the highest prevalence was 2.88% in studies performing both liver biochemistry and ERCP/MRCP, and the lowest was 1.79% in studies using a clinical diagnosis. Prevalence was generally higher in men, patients with more extensive, compared with left-sided, UC or ileocolonic or colonic, compared with ileal, CD.<h4>Conclusions</h4>Our findings provide the first pooled estimates of the burden of PSC in IBD, as well as potential risk factors, which may be important in establishing a prompt diagnosis and initiating appropriate surveillance for relevant gastrointestinal malignancies.