IgG4-related autoimmune liver disease

Area of Science:

• Hepatology
• Immunology
• Gastroenterology

Background:

• IgG4-related autoimmune liver disease (AILD) encompasses IgG4-related sclerosing cholangitis and pseudotumor, mimicking bile duct cancer and primary sclerosing cholangitis.
• While direct autoimmune phenomena are not definitively established in IgG4-AILD, immune system perturbations and humoral response activation are key pathophysiological aspects.
• Clinical presentations of IgG4-AILD involve biliary tract thickening and mass-forming lesions leading to obstruction, complicating diagnosis.

Purpose of the Study:

• To review the current understanding of IgG4-related autoimmune liver disease (AILD), focusing on its clinical manifestations, diagnostic challenges, and evolving treatment strategies.
• To highlight the diagnostic difficulties due to overlapping symptoms with other biliary diseases and the lack of specific biomarkers.
• To discuss the therapeutic landscape, including the role of glucocorticoids, the potential of B-cell depletion therapy, and future research priorities.

Main Methods:

• Review of existing literature on IgG4-related autoimmune liver disease (AILD).
• Analysis of clinical, serological, radiological, and histological diagnostic criteria.
• Evaluation of treatment responses to glucocorticoids and emerging biologics.

Main Results:

• IgG4-AILD diagnosis requires integrating multiple findings due to lack of reliable biomarkers, and it often mimics other serious biliary conditions.
• IgG4-AILD typically responds well to glucocorticoids but is prone to relapse, necessitating long-term therapy to prevent liver cirrhosis.
• B-cell depletion therapies show promise for systemic IgG4-related disease (IgG4-RD) and are influencing the treatment paradigm for IgG4-AILD.

Conclusions:

• Accurate diagnosis of IgG4-AILD is challenging, relying on a comprehensive approach combining clinical, serological, imaging, and pathological data.
• Effective management of IgG4-AILD involves initial glucocorticoid therapy followed by long-term maintenance to prevent disease progression and fibrosis.
• Future directions emphasize developing reliable biomarkers and less invasive biopsy techniques for improved diagnosis and management of IgG4-AILD, with biologics playing an increasing role.