Primary sclerosing cholangitis associated colitis: Characterization of clinical, histologic features, and their associations with liver transplantation.

Background: Primary sclerosing cholangitis (PSC) associated inflammatory bowel disease (IBD) is a unique form of IBD (PSC-IBD) with distinct clinical and histologic features from ulcerative colitis (UC) and Crohn disease (CD). In patients with PSC and IBD, the severity of the two disease processes may depend on each other.

Aim: To study the histologic and clinical features of PSC patients with and without IBD.

Methods: We assessed specimens from patients with UC ( = 28), CD ( = 10), PSC and UC (PSC-UC; = 26); PSC and CD (PSC-CD; = 6); and PSC and no IBD (PSC-no IBD; = 4) between years 1999-2013. PSC-IBD patients were matched to IBD patients without PSC by age and colitis duration. Clinical data including age, gender, age at IBD and PSC diagnoses, IBD duration, treatment, follow-up, orthotopic liver transplantation (OLT) were noted.

Results: PSC-UC patients had more isolated right-sided disease ( = 0.03), and less active inflammation in left colon, rectum ( = 0.03 and = 0.0006), and overall ( = 0.0005) compared to UC. They required less steroids ( = 0.01) and fewer colectomies ( = 0.03) than UC patients. The PSC-CD patients had more ileitis and less rectal involvement compared to PSC-UC and CD. No PSC-CD patients required OLT compared to 38% of PSC-UC ( = 0.1). PSC-IBD (PSC-UC and PSC-CD) patients with OLT had severe disease in the left colon and rectum ( = 0.04).

Conclusion: PSC-UC represents a distinct form of IBD. The different disease phenotype in PSC-IBD patients with OLT may support liver-gut axis interaction, however warrants clinical attention and further research.