What is primary biliary cholangitis (PBC)?

From the Guidelines

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by progressive destruction of small bile ducts, leading to cholestasis, fibrosis, and eventually cirrhosis, diagnosed with confidence on a combination of abnormal serum liver tests and presence of antimitochondrial antibodies (AMA) in serum 1.

Key Characteristics of PBC

• PBC primarily affects middle-aged women and is caused by an autoimmune attack on bile duct cells, triggered by environmental factors in genetically susceptible individuals.
• The disease leads to bile acid accumulation in the liver, causing inflammation and progressive damage.
• Patients with PBC may present with symptoms such as fatigue, pruritus, and/or jaundice, but the majority of them are asymptomatic at diagnosis.

Diagnosis and Management

• A detailed history and physical examination are essential for diagnosis, along with ultrasound as the first-line non-invasive imaging procedure to differentiate intra- from extrahepatic cholestasis 1.
• Testing for serum antimitochondrial antibodies (AMA) is mandatory in adults with chronic intrahepatic cholestasis 1.
• The diagnosis is confirmed by disclosing characteristic histological features of florid bile duct lesions.
• The first-line treatment is ursodeoxycholic acid (UDCA) at a dose of 13-15 mg/kg/day, taken orally in divided doses, which should be started immediately upon diagnosis, even in asymptomatic patients, as it slows disease progression and improves survival when initiated early 1.
• For patients with inadequate response to UDCA after 12 months, obeticholic acid (5-10 mg daily) can be added as second-line therapy.
• Symptom management is also important, including cholestyramine (4 g before meals) for pruritus, fat-soluble vitamin supplementation (vitamins A, D, E, K) for malabsorption, and calcium/vitamin D for osteoporosis prevention.
• Regular monitoring of liver function tests every 3-6 months is essential.

Lifestyle and Support

• Patients with PBC can take exercise, and in fact, there is some pilot trial evidence that exercise therapy is helpful for the treatment of fatigue 1.
• There is no specific dietary restriction for patients with PBC, but fat-soluble vitamin deficiency should be considered in patients with cholestasis or malabsorption syndromes 1.
• Patients with PBC are advised to stop smoking, as smoking is more prevalent and may be associated with more aggressive disease 1.
• There is no evidence to support an association between alcohol consumption and PBC development or disease severity, but patients with advanced liver disease are advised to abstain from alcohol 1.

From the FDA Drug Label

OCALIVA is a prescription medicine used to treat primary biliary cholangitis (PBC) in combination with ursodeoxycholic acid (UDCA) in adults who have not responded well enough to UDCA, or alone in adults who cannot tolerate UDCA. The answer to what primary biliary cholangitis (PBC) is, is not directly stated in the provided drug labels.

• The labels do mention that OCALIVA is used to treat PBC, but they do not provide a definition or description of the condition itself 2. No conclusion can be drawn about the definition of PBC from the provided information.

From the Research

Definition and Characteristics of Primary Biliary Cholangitis (PBC)

• Primary biliary cholangitis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course 3.
• It is characterized by slow destruction of small intrahepatic bile ducts, impaired biliary secretion, and stasis of toxic endogenous bile acids within the liver, leading to liver fibrosis and cirrhosis 4.
• PBC primarily affects women, with a female preponderance of 9-10:1, and a prevalence of up to 1 in 1,000 women over 40 years of age 3.

Symptoms and Diagnosis of PBC

• Common symptoms of PBC include fatigue and pruritus, but most patients are asymptomatic at first presentation 3, 5.
• Diagnosis is based on sustained elevation of serum markers of cholestasis, such as alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex 3, 6.
• Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate, and progressive loss of small intrahepatic bile ducts 3.

Treatment and Management of PBC

• Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC, and it can slow disease progression and improve survival 3, 7, 6.
• UDCA is effective in a majority of patients with PBC, but nearly a third of patients are non-responders and may require additional medical therapy and/or liver transplantation 5, 7.
• Novel therapies, such as obeticholic acid (OCA), are being investigated for the treatment of PBC, and management of side effects such as pruritus and fatigue is also being explored 7.