Serum biomarkers for the differentiation of autoimmune pancreatitis from pancreatic ductal adenocarcinoma

Table 1 Diagnostic criteria for autoimmune pancreatitis

Radiology	Serology	Histology	Response to steroid
Parenchyma:Diffuse enlargement with enhancement	IgG4 > 2 x upper limit of normal value	At least three	< 2 wk radiologically demonstrable resolution or marked improvement pancreatic/extrapancreatic manifestations
Duct: > 1/3 length of the main pancreatic duct		Periductal lymphoplasmacytic infiltrate without granulocytic infiltration
Atypical: Segmental/focal narrowing with duct < 5 mm		Storiform fibrosis
Other organ involvement: Bile duct: Segmental/multiple proximal or distal stricture		Obliterative phlebitis
Retroperitoneal fibrosis		> 10 IgG4-positive cells/high power field
Salivary/lachrymal glands: Symmetrically enlarged
Renal involvement

IgG4: Immunoglobulin G4.