Autoimmune Pancreatitis: Approach to Diagnosis and Treatment

Abstract

Autoimmune pancreatitis (AIP) is a chronic inflammatory disease of the pancreas that has classically been divided into distinct histologic and clinical subtypes [1]. Type I AIP, previously referred to as lymphoplasmacytic sclerosing pancreatitis, is the pancreatic manifestation of IgG4-related disease, which often occurs in the context of multi-organ involvement. In this context, type 1 AIP is most typically associated with IgG4-related cholangitis.  Type II AIP, or idiopathic duct-centric pancreatitis, is typically a pancreas-isolated disease although approximately 30% of cases are associated with inflammatory bowel disease (IBD).  More recently, type 3 AIP has been described as an immunological sequelae of immune-checkpoint inhibitor therapy [2]. This review will focus on the more classic subtypes of AIP, type 1 and 2.  Although AIP is rare, prompt recognition is crucial as early intervention and disease control can prevent complications related to irreversible pancreatic damage such as exocrine pancreatic insufficiency and diabetes mellitus.