Primary biliary cholangitis: primary autoimmune disease or primary secretory defect

Area of Science:

• Hepatology and immunology
• Gastroenterology
• Autoimmune liver diseases

Background:

• Primary biliary cholangitis (PBC) is a chronic, autoimmune liver disease predominantly affecting females, characterized by immune-driven destruction of intrahepatic bile ducts.
• PBC is frequently associated with other autoimmune conditions, suggesting a complex immune-mediated etiology.
• Emerging hypotheses propose a role for a defective 'biliary umbrella' in cholangiocyte damage and bile composition imbalance.

Approach:

• A systematic literature review was conducted using PubMed, Scopus, and Science Direct.
• The review encompassed studies published between 1986 and 2023.
• The analysis focused on understanding the current state of knowledge regarding PBC pathogenesis.

Key Points:

• The pathogenesis of PBC is understood as a complex interplay of genetic susceptibility and immune-mediated processes.
• Immune responses to autoantigens trigger progressive bile duct destruction, fibrosis, and cirrhosis.
• A compromised 'bicarbonate umbrella' may impair protection against toxic bile acids, contributing to bile toxicity.

Conclusions:

• Current understanding suggests PBC pathogenesis arises from a synergistic relationship between immune insults and disrupted biliary secretory mechanisms.
• Further research into the 'biliary umbrella' defect could offer new insights into PBC development.
• This review consolidates current knowledge, highlighting the multifaceted nature of PBC pathogenesis.