Primary sclerosing cholangitis (PSC)

Primary sclerosing cholangitis (PSC) is a chronic disease characterized by inflammation and scarring of the bile ducts resulting in narrowing (strictures) of the biliary tree.

The cause and mechanism of the disease is still largely unknown although is likely multifactorial process involving genetic and environmental risk factors, activation of the immune system and disorder of bile production by the liver.

Young males are mainly affected, with an average age at diagnosis of 40 years.

While many people have no symptoms, the majority complain of tiredness, itchiness, yellowing of the skin and eyes (jaundice), fevers and abdominal pain. The majority of people with PSC also have inflammatory bowel disease.

Liver function tests are usually abnormal (increased serum alkaline phosphatase (ALP) most commonly) and the bilirubin level can be raised with biliary obstruction.

The diagnosis is usually made by liver imaging with MRI/MRCP which show the derangement of the bile ducts both within and outside the liver although is some cases only the smaller biliary ducts within the liver are involved (small-duct PSC). It is important that secondary causes of sclerosing cholangitis are excluded.

PSC can be complicated by the episodes of cholangitis (biliary infections), requiring antibiotics. Jaundice due single ‘dominant strictures’ of the bile duct may present with jaundice and require treatment by endoscopy (ERCP). In some cases PSC progresses to cirrhosis, which may require liver transplantation. Unfortunately, in the absence of effective drug treatments, transplantation remains the only treatment proven to be effective for selected patients with PSC, particularly those with liver failure or severe symptoms due to blockage of the bile ducts. Mostly however, symptoms such as pruritus can be improved by drug treament (ursodeoxycholic acid, cholestyramine, rifampicin, naltrexone, sertraline) or other approaches such as liver dialysis (MARS). 

A further feature of PSC is the increased risk of developing several cancers (bowel, liver, bile duct and pancreas). With early diagnosis of PSC routine surveillance for such cancers is recommended using liver ultrasounds and colonoscopies.