Primary sclerosing cholangitis is associated with a specific IBD phenotype

Primary sclerosing cholangitis is associated with a distinct phenotype of inflammatory bowel disease, reports the latest issue of Inflammatory Bowel Diseases.

Primary sclerosing cholangitis is strongly associated with inflammatory bowel disease.

Dr Kirsten Boonstra and colleagues from the Netherlands assessed the inflammatory bowel disease (IBD) phenotype associated with primary sclerosing cholangitis in a large well-phenotyped population-based

The team studied a primary sclerosing cholangitis cohort using endoscopic and histopathologic criteria.

Primary sclerosing cholangitis cases were identified and ascertained, fulfilling well-established criteria, in 39 hospitals in a geographically defined region of the Netherlands.

The research team recorded the inflammatory bowel disease location according to the Montreal Classification.

As this classification does not consider segmental inflammation, backwash ileitis, or rectal sparing, an additional subgroup analysis was performed in 80 cases and 80 age- and sex-matched inflammatory bowel disease controls.

The team reviewed all endoscopy and pathology reports filed between 2000 and 2010.

In all, 380 of a total of 579 primary sclerosing cholangitis patients had coexistent inflammatory bowel disease, mainly ulcerative colitis.

The team found that overall, 207 of the primary sclerosing cholangitis patients had a pancolitis, 32 a left-sided colitis, and 9 a proctitis only.

The research team noted that 70 primary sclerosing cholangitis-Crohn's disease patients had an (ileo)colitis, and 4 had ileitis only.

In the subgroup analysis, the doctors identified 53 primary sclerosing cholangitis patients, 24  primary sclerosing cholangitis patients, and 3 primary sclerosing cholangitis-IBD patients.

The team found that 50 primary sclerosing cholangitis patients had a pancolitis, compared with 32 matched ulcerative colitis patients.

Left-sided colitis was seen in 16 ulcerative colitis controls, and in 1 primary sclerosing cholangitis patient.

Backwash ileitis and rectal sparing were rare findings in the cohorts under study.

Dr Boonstra's team conclued,  "Inflammatory bowel disease in primary sclerosing cholangitis patients represents a distinct phenotype in that pancolitis is observed in 94% of primary sclerosing cholangitis, and colitis in 96% of primary sclerosing cholangitis patients."

"Backwash ileitis and rectal sparing were rare findings in the primary sclerosing cholangitis patients."