The Impact of Concomitant Ulcerative Colitis on the Clinical Course in Patients with Primary Sclerosing Cholangitis: An Investigation Using a Nationwide Database in Japan

Introoduction: Primary sclerosing cholangitis (PSC) is a rare disease, especially in Asian countries. PSC often develops during ulcerative colitis (UC). Little is known about the severity of PSC in patients with UC. Thus, this study aimed to investigate the impact of concomitant UC on the clinical course of patients with PSC using a nationwide database in Japan. Methods: We collected data on patients who were admitted for PSC using a nationwide database and divided eligible admissions according to concomitant UC (PSC-UC group vs. PSC-alone group). We conducted propensity score matching and compared the rates of liver transplantation, biliary drainage, and other clinical events between the two groups. We also conducted a multivariate analysis to identify the clinical factors that affect biliary drainage, cholangiocarcinoma, and liver transplantation. Results: We enrolled 672 patients after propensity score matching. The rate of liver transplantation in the PSC-UC group was lower than that in the PSC-alone group (2.2 vs. 5.4%, p = 0.002), whereas the rate of biliary drainage did not differ between the two groups (38.1 vs. 33.8%, p = 0.10). On multivariate analysis, concomitant UC was identified as a clinical factor that decreased the risk of liver transplantation (odds ratio = 0.40, 95% confidence interval: 0.23–0.68, p = 0.0007). Discussion: Concomitant UC in patients with PSC may decrease the risk of liver transplantation. The milder disease activity of PSC with UC is more likely compared to that of PSC without UC.