Mucosal immunity in liver autoimmunity: a comprehensive review

Area of Science:

• Hepatology
• Immunology
• Gastroenterology

Background:

• Autoimmune liver diseases (AILDs) including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC) involve immune-mediated liver injury.
• These conditions are frequently associated with gut inflammation and conditions like inflammatory bowel disease (IBD), celiac disease, and IgG4-related disease.
• Th17-cells and mucosal immunity are increasingly recognized as playing a role in the pathogenesis of AILDs.

Purpose of the Study:

• To explore the link between gut inflammation, mucosal immunity, and the pathogenesis of autoimmune liver diseases.
• To investigate the role of Th17-cells and T-cell homing in AIH, PBC, and PSC.
• To identify potential novel therapeutic strategies targeting immune pathways in AILDs.

Main Methods:

• Review of existing literature and clinical observations linking gut inflammation to AILDs.
• Analysis of the role of Th17-cells and mucosal immune responses in liver injury.
• Exploration of T-cell recruitment mechanisms and their implications for disease distribution.

Main Results:

• A strong association exists between AIH, PBC, PSC, and gut inflammation, including IBD and celiac disease.
• Gut-restricted immune responses, particularly involving Th17-cells and mucosal memory T-cells, are implicated in AILD pathogenesis.
• Gene polymorphisms suggest a fundamental role for mucosal immunogenicity in conditions like PSC/IBD susceptibility.

Conclusions:

• The gut plays a critical role in the immunopathogenesis of autoimmune liver diseases.
• Targeting gut-specific immune pathways and lymphocyte homing presents promising avenues for novel therapeutic interventions in AIH, PBC, and PSC.
• Dysregulated mucosal immunity may underlie hepatic manifestations in various conditions, including graft-versus-host disease and gluten-sensitive enteropathy.