Autoimmune Pancreatitis (AIP) is a pancreatic 
inflammatory disease caused by an autoimmune 
mechanism. Histologically, two subtypes exist: type 1 
characterized by lymphoplasmacytic sclerosing pancreatitis 
and type 2 characterized by idiopathic duct-centric chronic 
pancreatitis. Type 1 AIP often involves extra pancreatic 
lesion, and also known as a pancreatic lesion of systemic 
“immunoglobulin G4 (IgG4)-related disease”. In addition, 
pancreatic endocrine dysfunction induced diabetes mellitus 
and exocrine dysfunction is common complications. While 
steroid therapy improves the outcome of the disease in some 
patients including pancreatic endocrine/exocrine function, 
others do not respond to steroids that results in the eventual 
progression to pancreatic endocrine/exocrine dysfunction, 
such as chronic pancreatitis. In the management of type 1 
AIP, presence of pancreatic endocrine/exocrine function 
should always be considered, in addition to the regular 
steroid therapy. 

Keywords: Autoimmune pancreatitis; Diabetes mellitus; 
Endocrine
 dysfunction;
 Exocrine
Immunoglobulin G4 (IgG4); Steroid therapy 
 dysfunction; 

Abbreviations: AIP: Autoimmune Pancreatitis; AQP-1: 
aquaporine-1; CP: Chronic Pancreatitis; CFTR: Cystic 
Fibrosis Transmembrane Conductance Regulator; DM: 
Diabetes Mellitus; GEL: Granulocyte Epithelial Lesions; 
IDCP: Idiopathic Duct-centric Chronic Pancreatitis; IgG4: 
Immunoglobulin
 G4;
Sclerosing Pancreatitis 
 LPSP: 
LymphoPlasmacytic