Primary biliary cholangitis Flashcards
What is Primary Biliary Cholangitis (PBC) and what causes it?
PBC is an autoimmune condition where the immune system attacks the small bile ducts in the liver, leading to obstructive jaundice and liver disease. It was previously known as Primary Biliary Cirrhosis.
What happens in the liver during Primary Biliary Cholangitis?
In PBC, the immune system causes inflammation and damage to the intrahepatic bile ducts (small bile ducts). This leads to bile flow obstruction (cholestasis), resulting in liver fibrosis, cirrhosis, and eventual liver failure. Bile acids, bilirubin, and cholesterol build up in the blood, leading to various symptoms like itching and jaundice.
What are the common symptoms and signs of Primary Biliary Cholangitis?
Common symptoms include:
* Fatigue
* Pruritus (itching)
* Gastrointestinal symptoms (e.g., abdominal pain)
* Jaundice
* Pale, greasy stools (due to fat malabsorption)
* Dark urine (due to bilirubin excretion)
On examination, patients may have:
* Xanthomas and xanthelasma (cholesterol deposits)
* Excoriations (scratches due to itching)
* Hepatomegaly
* Signs of cirrhosis and portal hypertension (e.g., splenomegaly, ascites) in advanced disease.
What tests are used to diagnose Primary Biliary Cholangitis?
Tests include:
* Liver function tests: Raised alkaline phosphatase (early sign), followed by elevated liver enzymes and bilirubin.
* Autoantibodies:
* Anti-mitochondrial antibodies (AMA): Most specific test for PBC.
* Anti-nuclear antibodies (ANA): Present in 35% of patients.
* Ultrasound: Helps exclude other liver diseases but doesn’t show specific PBC changes.
* Liver biopsy: May be used for diagnosis and staging.
* Raised immunoglobulin M (IgM) is often found.
What are the two key findings to remember for diagnosing Primary Biliary Cholangitis?
The two key findings are:
* Anti-mitochondrial antibodies (AMA)
* Raised alkaline phosphatase
A middle-aged white woman presenting with itching, positive AMA, and raised alkaline phosphatase likely has PBC.
What is the first-line treatment for Primary Biliary Cholangitis?
The first-line treatment is Ursodeoxycholic acid (UDCA), a bile acid that protects bile ducts from damage, slows disease progression, and improves outcomes.
Other treatments include:
* Obeticholic acid (if UDCA is ineffective or poorly tolerated, but with potential side effects)
* Colestyramine (for pruritus)
* Fat-soluble vitamin replacement (A, D, E, K)
* Immunosuppressive therapy (e.g., steroids) in some cases
* Liver transplant in end-stage liver disease.
What are the potential complications of Primary Biliary Cholangitis?
Potential complications include:
* Fat-soluble vitamin deficiency (A, D, E, K)
* Osteoporosis
* Hyperlipidaemia (raised cholesterol)
* Sjögren’s syndrome (dry eyes, dry mouth, vaginal dryness)
* Connective tissue diseases (e.g., systemic sclerosis)
* Thyroid disease
* Liver cirrhosis and complications such as portal hypertension and hepatocellular carcinoma in advanced disease.
