Introduction
Primary sclerosing cholangitis (PSC) is a cholestatic disease characterised by diffuse inflammation and fibrosis of the entire biliary tree. This leads to the gradual obliteration of both the intrahepatic and extrahepatic bile ducts.
Epidemiology
More common in men aged 25 to 40 years old. Male to female ratio is 3:1.
Associated conditions
75% of patients have inflammatory bowel disease, usually ulcerative colitis.
- Inflammatory bowel disease
- Chronic pancreatitis
- Sjögren’s syndrome
- Retroperitoneal fibrosis
Pathophysiology
PSC develops due to inflammation of the bile ducts (cholangitis) with consequent structuring and sclerosis. It may be intrahepatic and/or extrahepatic, although extrahepatic lesions are more common. This obstructs bile flow, which further perpetuates bile duct and liver injury
The cause of primary SPC is unknown. Secondary causes may include previous bile duct surgery, bile duct stones, alcohol insertion into hepatic tumours and parasite infections.
Clinical features
PSC is usually asymptomatic and found incidentally, especially in blood tests of patients with ulcerative colitis.
Symptomatic presentations include:
- Pruritus
- Intermittent jaundice
- Fatigue
- Weight loss
- Upper abdominal pain
- Hepatosplenomegaly
PSC eventually leads to cholestasis, cirrhosis and liver failure along with their respective presentations.
Investigations
Serum:
- LFT: raised ALP>ALT due to cholestasis. Advanced disease produces hypoalbuminaemia
- Antibodies: raised pANCA (perinuclear anti-neutrophil cytoplasmic antibodies)
Imaging: MRCP is the key investigation for diagnosing PCA. It shows multiple irregular structuring and dilatation of the biliary tracts.
Biopsy: shows ‘onion-skin’ fibrosis and inflammation around bile ducts, portal oedema and bile ductular proliferation.
Management
There is no cure available for PSC. Ursodeoxycholic acid (UDCA) is widely used, although there is little evidence of its efficacy. Treatments showed be aimed at managing cholestasis and its complications.
Transplantation is the only proven treatment for PSC and can be offered in advanced disease. 5-year survival is 80-90%, although PSC may recur.
Symptomatic therapy
Pruritus can be managed with cholestyramine.
Acute episodes of cholangitis should be treated with broad-spectrum antibiotics to cover potential bacterial infection.
Fat-soluble vitamin supplements should be offered in cases of malabsorption.
Prognosis
Symptomatic patients have a median survival of 12 years from the time of presentation. The most common cause of death is liver failure, although other causes include bile duct carcinoma, colonic carcinoma and complications of inflammatory bowel disease.
10-30% of PSC patients develop cholangiocarcinoma.
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