24th July 2023

Primary sclerosing cholangitis (PSC)

PSC is an autoimmune disease characterised by inflammation of the medium and large-sized bile ducts, leading to strictures and progressive fibrosis. It is also covered in greater detail in the Hepatic Pathology topic.

There is a strong association with inflammatory bowel disease (IBD), particularly ulcerative colitis. Unlike most autoimmune diseases, it is more common in men than women.

PSC is commonly asymptomatic but may present with fatigue, pruritus and abdominal pain. In more advanced disease, patients may present with features in keeping with chronic liver disease.

LFTs typically demonstrate a cholestatic pattern (raised ALP and GGT). In more advanced disease, bilirubin will also be elevated. There are no diagnostic autoantibodies associated with PSC. The key diagnostic investigation is imaging – ultrasound is first line and can be used to exclude other causes of cholestasis. MRCP is the gold standard test, with the more invasive ERCP an alternative if diagnosis is still unclear. Typically, MRCP demonstrates a “beaded’’ appearance of the ducts, caused by multiple strictures. Liver biopsy is not generally required.

Cholestyramine is used for symptomatic management of pruritus, and balloon dilation of strictures can be used to target the disease process. If the disease progresses to end-stage liver disease, transplantation is the only option.

Complications include osteopenia, chronic liver disease, cirrhosis, and cholangiocarcinoma.