IgG4 Related Autoimmune Pancreatitis: An Overview and the Emerging Role of Serum Eotaxin as a Potential Treatment Target.

BACKGROUND

Autoimmune pancreatitis (AIP) is a rare disease that has been classified into two subtypes. Type 1 is believed to be mediated by immunoglobulin G4 (IgG4) and type 2 is related to granulocytic epithelial lesions, but the pathogenetic mechanisms in both are still unknown. The patho-mechanism of AIP type 1 is suggested to be secondary to autoimmunity or allergy due to the increased serum IgG4 and immunoglobulin E levels, abundant infiltration of IgG4, plasmacytes and lymphocytes in the pancreas, and fibrosis. Both types of AIP respond to steroid treatment. The relapse rate after remission is high and reaches 30-50% within 6-12 months in AIP type 1; however, in AIP type 2 relapse is rare. The maintenance therapy and therapeutic strategy for relapsing patients with type 1 is managed with low dose steroids, however there are no consensus guidelines. In this review we discuss the current understanding of AIP, highlighting the emerging potential role of eotaxin in pathogenesis, classification, and management of the disease.