Background: Inflammatory bowel diseases (IBDs), comprising Crohn's disease (CD) and Ulcerative colitis (UC), are characterized by chronic remittent intestinal inflammation and carry the risk for extraintestinal manifestations including primary sclerosing cholangitis (PSC). There is conflicting data on the possible impact of PSC on the course of IBD. Therefore, aim of our study was to compare the disease course in IBD patients with and without coincident PSC.
Methods: A cohort of 1814 patients with histologically confirmed IBD was evaluated. In detail, medical records from 705 UC patients and 1022 CD patients as well as from 77 UC-PSC patients and 10 CD-PSC patients were assessed. In matched-pair analyses IBD patients without and with PSC were matched at the ratio of 3:1 by sex, disease entity, age at diagnosis, time from diagnosis to hospital presentation, and duration of follow-up. Time to event analyses were performed using survival analytic methods (Kaplan-Meier method and the Log-rank test).
Results: PSC was diagnosed in 77 and 10 patients out of 781 UC patients (9.9%) and 1033 CD patients (0.96%), respectively. While average age at diagnosis was 32 years in UC patients without PSC, UC-PSC patients were diagnosed significantly earlier at the age of 26 years (p<0.001). In CD patients, average age at diagnosis was found to be of 27 years vs. 24 years of age in CD-PSC patients. While extensive disease manifestation was observed in 46% of UC patients, pancolitis was more frequently diagnosed in UC-PSC patients (75%). Colorectal high grade intraepithelial neoplasia (HGIEN) and CRC were detected in 25 IBD patients without PSC and in 7 IBD-PSC (4 UC and 3 CD) patients (1.45% vs. 8.05%). Importantly, in IBD-PSC patients HGIEN/CRC occurred significantly earlier than in IBD patients without PSC (32 years vs. 50 years; p=0.019). Biological therapy including vedolizumab and antibodies targeting TNF was initiated in 37.3% of IBD patients and in 27.9% of IBD-PSC patients. Interestingly, there was a trend to commence biological therapy earlier in IBD patients as compared to IBD-PSC patients (median 20.4 vs. 28.6 years after onset, p=0.087). No significant differences between IBD and IBD-PSC patients were observed with respect to the time to first surgical intervention.
Conclusions: In our large cohort study, we found that IBD patients with coincident PSC show a distinct disease course with earlier disease onset and higher risk for extensive disease manifestation in UC. Furthermore, the risk for colorectal dysplasia development in IBD patients with coincident PSC was markedly increased as compared to IBD patients without PSC. Therefore, regular surveillance colonoscopies are essential in the clinical management of IBD patients suffering from PSC.