­­Primary Sclerosing Cholangitis (PSC)

 

Definition of primary sclerosing cholangitis

• Idiopathic disorder characterised by inflammation, fibrosis and structuring of the intra and extra-hepatic bile ducts.

 

 Epidemiology of primary sclerosing cholangitis

• Male:Female = 2:1
• Usually presents from 20-30 years old onward but can present earlier
• Studies show a prevalence varying from 0.2 to 8.5 per 100,000
• Higher prevalence in areas where ulcerative colitis is more common

 

 Aetiology of primary sclerosing cholangitis

• PSC is strongly associated with inflammatory bowel disease (IBD)
  • Most studies show an IBD prevalence of 60-80% in PSC patients
  • The commonest type is ulcerative colitis (UC): present in up to 80% of those with IBD and PSC.
• The underlying cause is unknown but there is thought to be an autoimmune component with a higher prevalence of certain HLA alleles (A1, B8, DR3).

 

 Presentations of primary sclerosing cholangitis

• History:
  • Fatigue
  • Pruritus
  • Weight loss
  • Right upper quadrant (RUQ) pain
  • Recurrent biliary infections
• Examination:
  • Jaundice
  • Hepatomegaly
  • Features of chronic liver disease
    • Dupuytren’s contracture; palmar erythema; gynaecomastia; spider naevi; ascites; cachexia
  • Features of IBD
    • Stoma; abdominal scars; mouth ulcers; erythema nodosum

 Differential diagnosis of primary sclerosing cholangitis

• Any other cause of chronic liver disease (see chronic liver disease section)

 

 Investigation of primary sclerosing cholangitis

• Blood tests:
  • Liver function tests
    • Usually show an elevated alkaline phosphatase, bilirubin and transaminases but these can all be in the normal ranges
  • Autoimmune profile
    • A range of autoantibodies can be present including ANCA , SMA and ANA
    • AMA (antimitochondrial) are usually absent
  • Full liver screen (see chronic liver disease section) to rule out other causes of cirrhosis

• Imaging:
  • Ultrasound liver
    • Not usually diagnostic and can be normal. Gallstones and gallbladder thickening can be seen.
  • Magnetic resonance cholangiopancreatography (MRCP)
    • This has become the diagnostic imaging of choice and is has none of the associated morbidity of ERCP.
    • Sensitivity > 80% and specificity >87% for PSC diagnosis

• Liver biopsy:
  • A biopsy is not needed for diagnosis of PSC.
  • Histological changes are often non-specific, especially in the early stages.
  • Liver biopsy is performed if MRCP and subsequent ERCP are non-diagnostic.

 

 Diagnosis of PSC (American Association of Liver Disease guidelines)

• Cholestatic liver biochemistry
• Cholangiography (MRCP or ERCP) showing characteristic changes to bile ducts including segmental strictures and dilatations

 

 Initial management of primary sclerosing cholangitis

• Anti-pruritics: as per management in PBC (see PBC pages)
• Vitamin A,D,E and K replacement
  • Vitamin D and Calcium replacement. Calcium 1g and vitamin D 800 IU daily
• If bacterial cholangitis
  • Antibiotics plus therapeutic drainage of the obstruction
  • Sometimes patients require long-term prophylactic antibiotics if they are suffering recurrent infections
• Stenting/drainage of strictures
  • Patients who are symptomatic from strictures with jaundice, cholangitis, RUQ pain or worsening liver function tests are candidates for intervention.
  • Endoscopic balloon dilatation, sphincterotomy and stent placement should be performed initially.
  • If endoscopic therapy is unsuccessful then biliary dilatation and/or stent placement should be attempted percutaneously.

Full guidelines on treatment can be found here: AASLD Guidelines – PSC

• Orthotopic liver transplant
  • Transplantation criteria are the same for PSC patients as for all patients with chronic liver disease and also include recurrent cholangitis, intractable pruritus and limited cholangiocarcinoma.
  • Outcomes are good with a 5-year survival rate of 85%.

 Further management of primary sclerosing cholangitis

• PSC patients with cirrhosis should be managed as for all chronic liver disease patients (see pages on chronic liver disease).

 

 Complications of primary sclerosing cholangitis

• Biliary infections
• Cirrhosis and associated complications (see pages on decompensated chronic liver disease)
• Cholangiocarcinoma
  • Patients with PSC have a higher risk for cholangiocarcinoma. Studies show a 10-year cumulative incidence of 7-9%.
  • Any PSC patient whose liver biochemistry deteriorates should be investigated for a possible underlying cholangiocarcinoma.

• Colorectal carcinoma
  • Patients with PSC and UC are at higher risk of developing colorectal carcinoma and should undergo colonoscopic surveillance 1-2 yearly from PSC diagnosis

 

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Common primary sclerosing cholangitis (PSC) exam questions for medical students, finals, OSCEs and MRCP PACES

 

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