Primary biliary cholangitis Flashcards
What is PBC
autoimmune condition characterised by granulomatous destruction of the intrahepatic biliary ducts, leading to cholestasis and subsequent leakage of bile into the circulation.
PBC epidemiology
- 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
Aetiology
immunological and serum anti-mitochondrial antibodies (AMA) - T cells target the cells in intrahepatic ducts and destroy them
RFs
F
Autoimmune conditions
FH
Smoking
Pregnancy
Pathophysiology of FBC
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.
50% of PBC patients have atleast one assosciated autoimmune condition such as
- Sjögren’s syndrome (25%)
- Raynaud’s phenomenon (25%)
- Autoimmune thyroid disease (25%)
- Rheumatoid arthritis (20%)
- Systemic sclerosis(10%)
Key presentation
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).
Signs
- Skin hyperpigmentation: due to increased melanin
- Clubbing
- Mild hepatosplenomegaly
Symptoms
- Pruritis (itchy skin) - leakage of bile salts
- Fatigue and weight loss
- Dry eyes and dry mouth - Sjögren’s syndrome
- Obstructive jaundic
Primary investigations
- 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
DDs
- Primary sclerosing cholangitis - AMA would not found
- Obstructive bile duct lesion
- Drug induced cholestasis - can do liver biopsy
1st line management
-
Ursodeoxycholic acid
- First-line agent in all patients, bile acid analgoue which dampen inflammatory response
- Fat soluble vitamin supplementation
- Codeine
- Bisphosphonates
2nd line
Liver transplantation
Monitoring
Regular LFTs + US
Complications
- 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