Primary biliary cholangitis

Question 1

What is PBC

Answer 1

autoimmune condition characterised by granulomatous destruction of the intrahepatic biliary ducts, leading to cholestasis and subsequent leakage of bile into the circulation.

Question 2

PBC epidemiology

Answer 2

• Rare disease with a prevalence of < 0.05%
• Middle-aged:peak incidence between 45 and 60 years old
• Female gender: ten times more common in females

Question 3

Aetiology

Answer 3

immunological and serum anti-mitochondrial antibodies (AMA) - T cells target the cells in intrahepatic ducts and destroy them

Question 4

RFs

Answer 4

F
Autoimmune conditions
FH
Smoking
Pregnancy

Question 5

Pathophysiology of FBC

Answer 5

The inflammatory process coupled with trapping of bile acids in the liver leads to progressive fibrosis, cirrhosis, and eventually liver failure.

The presence ofanti-mitochondrial antibodies (AMAs) has been observed in almost all patients with PBC, further reinforcing the likely autoimmune nature of the condition.

Question 6

50% of PBC patients have atleast one assosciated autoimmune condition such as

Answer 6

• Sjögren’s syndrome (25%)
• Raynaud’s phenomenon (25%)
• Autoimmune thyroid disease (25%)
• Rheumatoid arthritis (20%)
• Systemic sclerosis(10%)

Question 7

Key presentation

Answer 7

significant itching in a middle-aged female. Some patients may be asymptomatic and be simply diagnosed on a routine blood test demonstrating abnormal LFTs (e.g. raised ALP).

Question 8

Signs

Answer 8

• Skin hyperpigmentation: due to increased melanin
• Clubbing
• Mild hepatosplenomegaly

Question 9

Symptoms

Answer 9

• Pruritis (itchy skin) - leakage of bile salts
• Fatigue and weight loss
• Dry eyes and dry mouth - Sjögren’s syndrome
• Obstructive jaundic

Question 10

Primary investigations

Answer 10

• LFTs
• Antimitochondrial antibodies (AMA):present in 95% of patients (highly specific)
• Antinuclear antibodies (ANA):present in 50% of patients
• Raised serum cholesterol
• Maybe MRCP + Liver biopsy

Question 11

DDs

Answer 11

• Primary sclerosing cholangitis - AMA would not found
• Obstructive bile duct lesion
• Drug induced cholestasis - can do liver biopsy

Question 12

1st line management

Answer 12

• Ursodeoxycholic acid
  
  • First-line agent in all patients, bile acid analgoue which dampen inflammatory response
• Fat soluble vitamin supplementation
• Codeine
• Bisphosphonates

Question 13

2nd line

Answer 13

Liver transplantation

Question 14

Monitoring

Answer 14

Regular LFTs + US

Question 15

Complications

Answer 15

• Malabsorptionof fat-soluble vitamins A, D, E and K due to cholestasis; may result in coagulopathy due to decreased bilirubin in gut lumen
• Hypercholesterolaemia:cholestasis is associated with hypercholesterolaemia
• Liver cirrhosis:end-stage disease results in fibrosis and eventual cirrhosis, whilst portal hypertension may cause ascites and variceal bleeding
• Hepatocellular carcinoma: 20-fold increased risk
• Metabolic bone disease:osteoporosis and osteomalacia