Primary Biliary Cholangitis (PBC)

A 48-year-old woman presents to the clinic with several months of fatigue, generalized pruritus, and right upper quadrant discomfort. The pruritus is worse at night and has not improved with over-the-counter antihistamines. She has a history of Hashimoto thyroiditis treated with levothyroxine. She does not smoke or drink alcohol. Vital signs are normal, and physical examination is unremarkable. Laboratory studies show elevated alkaline phosphatase and gamma-glutamyl transferase with normal aminotransferases. Serum antimitochondrial antibodies are positive. Abdominal imaging shows no evidence of extrahepatic biliary obstruction. Diagnosis?

Diagnosis is Primary Biliary Cholangitis (PBC).

1. Definition

Primary biliary cholangitis is an autoimmune cholestatic liver disease characterized by progressive destruction of small intrahepatic bile ducts, leading to cholestasis, fibrosis, and eventual cirrhosis.

2. Epidemiology

1. Middle-aged women (40–60 years)
2. Strong female predominance
3. Frequently associated with autoimmune diseases

3. Associated Conditions

1. Hashimoto thyroiditis
2. Sjögren syndrome
3. Celiac disease
4. Other autoimmune disorders

4. Clinical Features

4.1 Core Features

1. Fatigue
2. Pruritus (earliest and most common symptom)
3. Cholestatic liver enzyme pattern (↑ ALP > AST/ALT)

4.2 Associated Features

1. Right upper quadrant discomfort
2. Hypercholesterolemia → xanthomas, xanthelasma
3. Steatorrhea due to fat malabsorption
4. Fat-soluble vitamin deficiency (A, D, E, K)
5. Jaundice (late finding)
6. Progression to cirrhosis and portal hypertension

5. Diagnosis

5.1 Laboratory Findings

1. Cholestatic pattern
• ↑ Alkaline phosphatase (ALP)
• ↑ Gamma-glutamyl transferase (GGT)
• Bilirubin often normal early, elevated in advanced disease
2. Hypercholesterolemia
3. Antimitochondrial antibodies (AMA) positive (highly specific)

5.2 Imaging

1. Ultrasound or MRCP
• Performed to exclude extrahepatic biliary obstruction

5.3 Histology (if needed)

1. Nonsuppurative destructive cholangitis
2. Lymphocytic infiltration of small intrahepatic bile ducts

➡ Liver biopsy is not required if AMA positive with typical cholestatic pattern

6. Management

6.1 First-Line Therapy

1. Ursodeoxycholic acid (UDCA)
• Improves biochemical markers and slows disease progression

6.2 Second-Line Therapy

1. Obeticholic acid
• Used in patients with inadequate response to UDCA

6.3 Symptomatic Treatment

1. Pruritus → cholestyramine (first-line)
2. Fat-soluble vitamin supplementation (A, D, E, K)
3. Osteoporosis management
• Calcium + vitamin D
• Bisphosphonates
4. Hypercholesterolemia → statins

6.4 Definitive Treatment

1. Liver transplantation
• Indicated in advanced disease
• Only curative therapy

7. Complications

1. Cirrhosis
2. Portal hypertension
3. Fat-soluble vitamin deficiencies
4. Osteoporosis
5. Hepatocellular carcinoma (advanced disease)

8. Key Clinical Insight

A middle-aged woman with pruritus, cholestatic liver enzyme elevation, positive AMA, and no biliary obstruction strongly suggests primary biliary cholangitis

9. Exam-Level Pearls

1. Pruritus is the earliest symptom
2. AMA is highly specific for PBC
3. Cholestatic pattern = ↑ ALP disproportionate to AST/ALT
4. Strong association with autoimmune diseases
5. First-line treatment = ursodeoxycholic acid
6. Pruritus treatment = cholestyramine
7. Differentiation:
• PBC = intrahepatic small ducts + AMA positive
• PSC = intra + extrahepatic ducts + p-ANCA + beading on MRCP