Introduction
Primary biliary cholangitis (PBC; previously known as primary biliary cirrhosis) is a chronic cholestatic liver disease characterised by destruction of the small bile ducts of the liver.
Granulomatous inflammation of the portal tracts leads to progressive damage and eventual loss of small and middle-sized bile ducts.
Epidemiology
Mainly affects middle-aged women; female to male ratio is 10:1. It is relatively common in Europe and North America but rare in Africa and Asia.
It is more common in smokers.
Risk factors
- HLA-DR8 serotype
- Smoking
Associated conditions
- Coeliac disease
- Thyroid disease
- Sjögren’s syndrome
- Systemic sclerosis
Pathophysiology
Most patients have antimitochondrial antibodies (AMA) against pyruvate dehydrogenase. Chronic granulomatous inflammation destroys the interlobular bile ducts. Progressive inflammation causes fibrosis, which spread from the portal tracts to the liver to lead to cirrhosis.
Clinical features
Most patients have vague chronic symptoms, including fatigue, pruritus (from cholestasis) and right upper abdominal discomfort.
Patients with advanced disease present with:
- Jaundice
- Severe pruritus
- Weight loss
- Hepatomegaly
Fibrosis can lead to liver failure and portal hypertension.
Investigations
Serum:
- LFT: raised ALP>ALT due to cholestasis
- Antibodies: raised AMA
- Immunoglobulins: raised IgM
Imaging: ultrasound scan would show no evidence of biliary obstruction.
Blood tests and clinical features are usually sufficient to make the diagnosis. Biopsies are only performed if the diagnosis is uncertain.
Management
Ursodeoxycholic acid (UDCA) is the first-line treatment for PBC and has few side-effects. It improves bile flow, replaces toxic hydrophobic bile acids in the bile pool and reduces epithelial apoptosis. There is no other useful alternative treatment available for the minority of patients that do not respond to UDCA.
Transplantation may be offered in advanced liver disease and offers a 5-year survival of 80%. However, there is a significant chance of disease recurrence.
Symptomatic therapy
Pruritus is the main symptom that requires treatment. Cholestyramine, rifampicin, naltrexone and plasmapheresis can be used to relieve pruritus.
Fat-soluble vitamin supplements should be offered in cases of malabsorption.
0 Comments