Autoimmune pancreatitis: Cornerstones and future perspectives

Table 1 Differential characteristics between type 1 and type 2 autoimmune pancreatitis

	AIP-1	AIP-2
Gender (M:F)	3:1	1:1
Mean age at disease onset	60-70 yr	40-60 yr
Epidemiology	Asia > Western Countries	Western Countries > Asia
Main clinical manifestations	Painless jaundice (75%); Abdominal symptoms (40%)	Abdominal pain and acute pancreatitis (50%)
	Weight loss
	Diabetes and exocrine pancreatic insufficiency
Extrapancreatic manifestations	IgG4-related disease extrapancreatic manifestations (50%)	IBD (49%-67%)
	Hepatobiliary disease
	Retroperitoneal fibrosis and/or aortitis
	Head and neck involvement
	Mikulicz syndrome
Serum IgG4 levels	Elevated (circulating IgG4 to IgG levels typically > 10%) (50%)	Normal (p-ANCA and c-ANCA autoantibodies often positive)
Histologic features	Lymphoplasmacytic infiltrates rich in IgG4+ plasma cells	Granulocytic epithelial lesions
	Storiform fibrosis
	Obliterative phlebitis
Steroid therapy	Responsive	Responsive
Relapse	High rate (39%)	Rare

AIP: Autoimmune pancreatitis; IBD: Inflammatory bowel disease; ANCA: Anti-neutrophil cytoplasmatic antibodies; IgG: Immunoglobulin G; AIP-1: Type 1 autoimmune pancreatitis; AIP-2: Type 2 autoimmune pancreatitis.