Overview Table

Primary Biliary Cholangitis (PBC) vs Primary Sclerosing Cholangitis (PSC)

Note that PBC and PSC are 2 distinct conditions, but they share several important similarities. It’s therefore essential to be able to differentiate between them:

• Both cause chronic cholestatic liver disease
• Both involve pathological injury to the biliary tree
• They sound similar!

Feature	PBC	PSC
Site of disease	Intrahepatic bile ducts	Intra- AND extrahepatic bile ducts
Association	Autoimmune diseases	Ulcerative colitis
Antibodies	AMA +ve	p-ANCA positive (non-specific)
Diagnosis	Imaging is non-diagnostic; biopsy is necessary	MRCP
Treatment	Ursodeoxycholic acid (UDCA)	Limited; liver transplant if advanced
Main complication	Osteoporosis, cirrhosis, hepatocellular carcinoma	Cholangiocarcinoma

Background Information

Definition

PSC is a chronic cholestatic liver disease, characterised by IDIOPATHIC progressive inflammation and destruction of BOTH intrahepatic and extrahepatic bile ducts.

Aetiology

PSC is idiopathic

 

The strongest association is with IBD, particularly ulcerative colitis ^[Ref]

• IBD is present in 70-88% of patients with PSC
• 5-10% of IBD patients develop PSC

Clinical Features

Patients often have concomitant ulcerative colitis (also see the Ulcerative Colitis (UC) article)

 

Patients may be asymptomatic. If symptomatic, mainly due to cholestasis:

• Fatigue
• Pruritus
• Jaundice
• RUQ pain
• Hepatosplenomegaly
• Features of cirrhosis seen in advanced disease (see the Cirrhosis article for more information)

Complications

Major complications: ^[Ref]

• Cholangiocarcinoma (400x risk compared to the general population)
• Cirrhosis
• Gallbladder cancer
• Colorectal cancer (esp. in those with concomitant IBD )
• Complications from chronic cholestasis
  • Fat-soluble vitamin (A D E K) deficiency
  • Osteoporosis

Diagnosis

Diagnostic criteria:

• Cholestatic LFTs, and
• Typical imaging findings, and
• Exclusion of secondary causes of sclerosing cholangitis

Blood Tests

LFTs	Cholestatic LFTs: ↑ ALP and GGT (with relatively normal AST and ALT) ↑ Bilirubin (conjugated hyperbilirubinaemia) is seen in more advanced disease (indicates worse prognosis)
Serology	There is NO diagnostic serological marker for PSC Autoantibodies (e.g. ANA, AMA, SMA ) may be +ve but are NOT specific or diagnostic

Imaging

Initial imaging: abdominal ultrasound

• To rule out common causes of biliary obstruction
• But it is NOT used to diagnose PSC

 

1st line (and gold standard) diagnostic imaging: MRCP 

• Classic beaded appearance from multifocal strictures and segmental dilatation of intra- and extra-hepatic bile ducts

Liver Biopsy

Liver biopsy is NOT routinely done, and is NOT necessary for diagnosis (see diagnostic criteria above)

 

Liver biopsy is only considered if:

• Imaging is normal, but clinical suspicion of PSC remains
• There is suspicion of overlap with autoimmune hepatitis
• Diagnostic uncertainty

 

Biopsy can demonstrate “onion skin” periductal fibrosis (rarely seen) and other features, but is usually non-specific.​

Management

Pharmacological Management

Disease-Modifying Therapy

There is currently NO recommended disease-modifying therapy for PSC

• Ursodeoxycholic acid is NOT recommended (it is used for PBC)
• Corticosteroids and immunosuppressants are NOT recommended

Symptom-Directed Therapy

Pruritus	1st line: cholestyramine (bile acid sequestrant) 2nd line: rifampicin / naltrexone
Fatigue	There are currently NO effective pharmacological management Treat direct contributors of fatigue

Interventional Treatment

ERCP  should NOT be routinely offered to patients with PSC

 

ERCP  (balloon dilatation preferred over stenting) is indicated to treat dominant strictures (symptomatic / worsening liver biochemistry)

• Empirical antibiotic prophylaxis should be given as PSC patients undergoing ERCP are at risk of post-ERCP cholangitis

Liver Transplantation

Liver transplantation is the only curative treatment for PSC

 

Liver transplant should be considered in those with advanced liver disease:

• Cirrhosis
• Portal hypertension
• Decompensated liver failure
• Recurrent / intractable bacterial cholangitis
• Severe pruritus
• Complicated biliary strictures

Monitoring

All patients at diagnosis of PSC should be screened for IBD with colonoscopy

• NB those with IBD require annual colonoscopic surveillance for colorectal cancer

 

Life-long disease monitoring for progression is necessary:

• Annual LFTs (at minimum)
• Non-invasive imaging to be performed for new / changing symptoms or evolving laboratory abnormalities

 

Recommended complication surveillance:

• Annual abdominal ultrasound (to screen for gallbladder cancer)
• Bone mineral density measurement (DEXA) (to screen for osteoporosis)
• If the patient develops cirrhosis, screen for complications accordingly
  • Ultrasound +/- AFP every 6 months (for HCC)
  • Upper GI endoscopy at baseline (for oesophageal varices)
  • See the Cirrhosis article for more details

References