PSC-IBD: specific phenotype of inflammatory bowel disease associated with primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is a progressive disease of the biliary tree which represents one of the most frequent indications for orthotopic liver transplantation (OLTx) in developed countries. LTx is currently the only curative procedure for PSC. Concomitant inflammatory bowel disease (IBD) is present in approximately 70 % of patients with PSC. Such colitis in PSC has specific clinical and etiological features and is considered as a distinct phenotype of IBD often referred to as "PSC-IBD". The phenotype usually manifests as mild extensive colitis with right-sided predominance. Other morphological features, such as back- wash ileitis and rectal sparing, are also increasingly prevalent in PSC-IBD. Moreover, patients with PSC-IBD have increased risk towards developing colorectal neoplasia which tend to be highly progressive. Therefore, total colonoscopy employing multiple random biopsies or chromoendoscopy should be performed every 1-2 years once PSC-IBD is diagnosed. Even detection of low-grade dysplasia in colonic mucosa should lead towards prophylactic colectomy consideration in patients with PSC-IBD. Recommendations regarding pharmacological therapy are based on the similar principles as in Crohn´s disease and ulcerative colitis. However, status of the liver disease should always be taken into account. Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is a method of choice in the field of surgical therapy of PSC-IBD. The clinical course of PSC-IBD may deteriorate after OLTx despite immunosuppressive therapy administration. IBD can even develop de-novo after OLTx and may significantly influence the risk ratio for PSC recurrence in the liver graft. Key words: inflammatory bowel disease - primary sclerosing cholangitis - PSC-IBD.