Endoscopic ultrasound-guided fine needle aspiration in the differentiation of type 1 and type 2 autoimmune pancreatitis

Table 1 Histological criteria for International Consensus Diagnostic Criteria

	Level 1	Level 2
Type 1 AIP
Histology of the pancreas	LPSP (core biopsy/resection)	LPSP (core biopsy)
	At least 3 of the following:	Any 2 of the following:
	(1) Periductal lymphoplasmacytic infiltrate without granulocytic infiltration	(1) Periductal lymphoplasmacytic infiltrate without granulocytic infiltration
	(2) Obliterative phlebitis	(2) Obliterative phlebitis
	(3) Storiform fibrosis	(3) Storiform fibrosis
	(4) Abundant (> 10 cells/HPF) IgG4-positive cells	(4) Abundant (> 10 cells/HPF) IgG4-positive cells
Type 2 AIP
Histology of the pancreas (core biopsy/resection)	IDCP
	Both of the following:	Both of the following:
	(1) GEL with or without granulocytic acinar inflammation (2) Absent or scant (0-10 cells/HPF) IgG4-positive cells	(1) Granulocytic and lymphoplasmacytic acinar infiltrate (2) Absent or scant (0-10 cells/HPF) IgG4-positive cells

AIP: Autoimmune pancreatitis; LPSP: Lymphoplasmacytic sclerosign pancreatitis; IDCP: Idiopathic duct-centric pancreatitis; GEL: Granulocytic infiltration of the duct wall; IgG4: Immunoglobulin G4; HPF: High power field.

Table 2 Results of endoscopic ultrasound-guided fine needle aspiration specimen n (%)

	Pancreatic head (n = 21)	Pancreatic body-tail (n = 26)	Total (n = 47)	P value
Average number of FNA passes	2.00 ± 0.43	2.04 ± 0.514	2.02 ± 0.48	0.78
	(1-3)	(1-4)	(1-4)
Adequate sample material	17 (80.9)	26 (100)	43 (91.4)	0.07
Lymphoplasmacytic infiltration	6 (28.6)	10 (38.4)	16 (34.0)	0.68
Storiform fibrosis	12 (57.1)	22 (84.6)	34 (72.3)	0.07
Obliterative phlebitis	0 (0)	0 (0)	0 (0)	1
Abundant IgG4-positive plasmacyte infiltration	3/10 (30)	7/18 (38.8)	10/28 (35.7)	1
Granulocytic infiltration of duct wall	0 (0)	0 (0)	0 (0)	1
Granulocytic acinar infiltrate	1 (4)	2 (7.7)	3 (6.3)	1
Complications	0 (0)	0 (0)	0 (0)	1

IgG4: Immunoglobulin G4; FNA: Fine needle aspiration.

Table 3 Patients with level 2 histological findings of lymphoplasmacytic sclerosing pancreatitis

Case	Sex	Age, yr	IgG4 (mg/dL)	Location	Response to steroid	OOI	Diagnosis
1	Male	74	263	Diffuse	(+)	Nephritis	Definitive type 1 AIP
2	Female	71	364	Diffuse	(+)	Cholangitis	Definitive type 1 AIP
3	Male	54	230	Focal	(+)	Sialadenitis	Definitive type 1 AIP
4	Male	47	104	Focal	(+)	None	Definitive type 1 AIP
5	Male	57	46	Focal	(+)	None	Definitive type 1 AIP

IgG4: Immunoglobulin G4; OOI: Other organ involvement; AIP: Autoimmune pancreatitis.

Table 4 Patients with level 2 histological findings of idiopathic duct-centric pancreatitis

Case	Sex	Age, yr	IgG4 (mg/dL)	Location	Response to steroid	OOI	Follow-up, d	Relapse	Diagnosis
1	Male	28	69	Diffuse	(+)	(-)	973	(-)	Probable type 2 AIP
2	Fe-male	31	43	Diffuse	(+)	(-)	425	(-)	Probable type 2 AIP
3	Male	30	23	Focal	(+)	(-)	120	(-)	Probable type 2 AIP

IgG4: Immunoglobulin G4; OOI: Other organ involvement; AIP: Autoimmune pancreatitis.