Published online Jul 28, 2020. doi: 10.3748/wjg.v26.i28.4126
Peer-review started: March 30, 2020
First decision: April 25, 2020
Revised: June 8, 2020
Accepted: July 15, 2020
Article in press: July 15, 2020
Published online: July 28, 2020
Primary Sclerosing cholangitis (PSC) associated inflammatory bowel disease (IBD) is a unique form of IBD seen in patients with PSC. It has been characterized as to have right sided predominance in colon with less severe active inflammation. Most cases of PSC-IBD are classified as ulcerative colitis (UC), whereas rare cases exhibit features of Crohn disease. There is thought to be a link between the IBD severity and the progression of PSC.
The need for better characterization of the pathologic findings in PSC-IBD patients and its association with liver transplantation may further support the “gut-liver axis” theory and has potential clinical implications. In addition, little is known regarding PSC-Crohn disease and its clinical outcomes.
The primary aims in this study were to characterize the colon and ileal findings in PSC patients at a tertiary care center, better define the histologic features of PSC-IBD, and explore if there is any correlation between the intestinal disease and liver transplant status, since this can impact patient management.
This retrospective study was conducted in a single tertiary care center. Based on data search, cases with PSC and lower gastrointestinal biopsies were identified. Care was taken to examine the most inflamed biopsy. The hematoxylin and eosin slides were re-reviewed and several morphologic features were recorded. Pertinent clinical data was collected.
Our study confirmed the previously reported histologic findings in PSC-UC patients including a predominantly right sided involvement with overall less severity. We also described detailed histologic features of PSC-Crohn disease (CD) patients. None of the PSC-CD patients required liver transplantation, in contrast to ten PSC-UC patients. In our study, there was no correlation between the clinical parameters or treatment and orthotopic liver transplantation (OLT). When all PSC-IBD patients were analyzed together, severe left sided colitis correlated with the need for OLT.
In our cohort, PSC-IBD patients with severe left sided and rectal disease required OLT more commonly than other PSC-IBD patients. This is rather interesting, since it may indicate that these patients are at increased risk for progression of their liver disease and this has not been reported before.
The findings in this study further support the notion that gut and liver interact through several different mechanisms. Our results raise the possibility that an only a subset of patients with PSC-IBD (severe disease activity in left colon in our cohort) may be at increased risk for faster progression of liver disease, and eventually receive OLT. However, the contribution of other factors such as microbiome, genetic underpinnings, or others remain unanswered and should be further studied.