Case 11 Discussion
Learning Objectives:
- Perform appropriate work up for the diagnosis of primary sclerosing cholangitis.
- Understand factors associated with risk of progression and poor prognostic factors in patients with primary sclerosing cholangitis.
- Relationship of inflammatory bowel disease and primary sclerosing cholangitis.
IBD EPAs:
EPA 1: Classify IBD phenotype, disease activity, and extraintestinal manifestations
EPA 2: Use advanced diagnostic and therapeutic endoscopic and radiographic techniques in the management of IBD
EPA 10: Apply preventive health strategies for patients with IBD
PSC is a progressive cholestatic liver disease leading to fibrosis and cirrhosis in the majority of patients with no effective medical treatment. PSC is a rare disease with a prevalence ranging from 4-16 per 100,000 person-years, is more common in men than women (2-3:1) and typically diagnosed between 30-40 years of age (1,2). The median survival in patients with PSC from diagnosis until liver transplant or death is estimated to be 21.3 years in population-based cohorts (3). About half of the patients with PSC are asymptomatic with normal physical exam on presentation and the diagnosis is suspected based on elevated liver enzymes in patients with IBD (4).
Diagnosis of PSC is based on a combination of clinical, laboratory and imaging studies. PSC should be suspected in all patients with IBD and elevated alkaline phosphatase (ALP) and/or gamma glutamyl transferase (GGT) values. MRCP is the modality of choice for the diagnosis of PSC. Most common (90%) is the classic subtype which affects both large and small bile ducts. Small duct PSC affects only small bile ducts resulting in a normal cholangiogram, and is seen in 5% patients. Small duct subtype has a better prognosis and lower risk of developing cholangiocarcinoma. PSC with features of autoimmune hepatitis (i.e. PSC-AIH overlap) is seen more commonly in children but can be seen in up to 5% of adults. Serum IgG4 is elevated in 10% patients with PSC and associated with worse outcomes than those without IgG4. Serum IgG4 level should be checked in every patient’s with suspected PSC (5). ERCP should be reserved for therapeutic rather than diagnostic purposes.
PSC is strongly associated with IBD (70-80%) and increases the risk of developing colon, bile-duct and gallbladder cancers and regular surveillance for these malignancies is warranted. There are no effective therapies for this disease. Liver transplantation should be considered for those with liver complications.
References:
- Bambha K, Kim WR, Talwalkar J, et al. Incidence, clinical spectrum, and outcomes of primary sclerosing cholangitis in a United States community. Gastroenterology 2003; 125: 1364-9.
- Hirschfield GM, Karlsen TH, Lindor KD, Adams DH. Primary sclerosing cholangitis. Lancet 2013; 382: 1587-99.
- Boonstra K, Weersma RK, van Erpecum KJ, et al. Population-based epidemiology, malignancy risk, and outcome of primary sclerosing cholangitis. Hepatology 2013; 58: 2045-55.
- Kaplan GG, Laupland KB, Butzner D,Urbanski SJ, Lee SS. The burden of large and small duct primary sclerosing cholangitis in adults and children: a population-based analysis. Am J Gastroenterol2007; 102: 1042-9).
- Webster GJ, Pereira SP, Chapman RW. Autoimmune pancreatitis/IgG4-associated cholangitis and primary sclerosing cholangitis– overlapping or separate diseases? J Hepatol 2009;51:398-402.