Recent advances in autoimmune pancreatitis: type 1 and type 2

Area of Science:

• Gastroenterology
• Immunology
• Pathology

Background:

• Autoimmune pancreatitis (AIP) is a chronic pancreatitis with distinct clinical, histological, and therapeutic features.
• AIP is sub-classified into Type 1 and Type 2, with international consensus criteria aiding diagnosis.
• Type 1 AIP is associated with IgG4-related disease, while Type 2 is pancreas-specific.

Purpose of the Study:

• To review the current understanding of autoimmune pancreatitis (AIP), including its subtypes, diagnosis, and management.
• To discuss the role of IgG4 in Type 1 AIP and the therapeutic responses to steroids and other agents.
• To outline the characteristics and management of Type 2 AIP.

Main Methods:

• Literature review of autoimmune pancreatitis (AIP) and IgG4-related disease.
• Analysis of clinical presentations, diagnostic criteria, and therapeutic outcomes for AIP subtypes.
• Synthesis of current research on pathogenesis, treatment regimens, and long-term outcomes.

Main Results:

• Type 1 AIP, associated with IgG4-related disease, responds to steroids, but relapses are common and may require long-term management with steroids or immunomodulators.
• IgG4's pathogenic role in Type 1 AIP is unlikely despite frequent association.
• Type 2 AIP is a distinct, pancreas-specific disorder responding to steroids, with uncommon relapses and ongoing evaluation of long-term outcomes.

Conclusions:

• Autoimmune pancreatitis (AIP) comprises two subtypes with different associations and management considerations.
• Steroid therapy is central to AIP management, but long-term strategies for relapsing Type 1 AIP are evolving.
• Further research is needed to optimize treatment for AIP relapses and remission maintenance.