Primary sclerosing cholangitis in Iceland 1992-2012

Background: Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease affecting the intra- and/or extrahepatic biliary tree with inflammation and progressive stricture formation that can lead to cirrhosis, end stage liver failure and liver transplantation. Known risk factors include inflammatory bowel diseases (IBD), mainly ulcerative colitis (UC). Highest reported incidence in an adult population is 1.21.3/100.000 in Norway and Sweden, where 60-76% have IBD. The aim of this study was to investigate epidemiology of PSC in Iceland in the years 1992 to 2012 and the patients outcomes. Methods: A search for the diagnosis "cholangitis" (ICD-10, K83.0) was performed in the database for hospital records in Landspitali (The National University Hospital of Iceland, LSH) and Akureyri Hospital from 1992 to 2012. We also looked through all ERCP and MRCP imaging done in LSH in the same period along with a text search in both the hospital records and the pathology database for liver biopsies. Data on these patients was collected until the end of 2016. Results: A total of 42 patient got the diagnosis PSC within the period. Median age at diagnosis was 34 years, 67% were male and 90% adults (>= 18 years old). Mean incidence per year was 0.69/100.000. Overall 88% of patients had IBD, thereof 89% UC. Seven patients have been diagnosed with cancer, four with cancer in the bile ducts and one in the gallbladder. Within the study period a total of five patients died (12%), 51 months (median) from diagnosis and three from cholangiocarcinoma, 51 months (median) from diagnosis. Three patients (7%) underwent liver transplantation, one required a transplant two times. Conclusions: The incidence of PSC in Iceland turned out to be lower than in our neighbouring countries in Scandinavia. It is unclear if this is due to underdiagnosis or, more likely, that PSC is simply more uncommon in Iceland. Overall 7% underwent liver transplantation and 12% died within the study period, main cause of mortality being cholangiocarcinoma.