Clinical and pathological differences between serum immunoglobulin G4-positive and -negative type 1 autoimmune pancreatitis

Table 1 Comparison of clinical characteristics of serum immunoglobulin G4-positive and negative type 1 autoimmune pancreatitis patients n (%)

Variables	SIP	SIN	P value
Patients	17	8
Mean age, yr	62 (33-84)	60 (42-72)	0.359
Sex (M/F)	13:4	5:3	0.172
Diffuse type	8 (47)	3 (31)	0.390
Median serum IgG4 (mg/dL)	312 (145-4000)	33 (6-75)	0.030
Other organ involvement	10 (59)	1 (26)	0.016
Histologic examination
Resection	5 (26)	6 (75)	0.018
Biopsy	6 (32)	2 (25)
Not done	6 (32)
Mean follow up, mo	30	16	0.075
Relapse	6 (35)	2 (25)	0.850

SIP: Serum immunoglobulin G4 (IgG4)-positive; SIN: Serum IgG4-negative; F: Female; M: Male.

Table 2 Clinical features of eight patients with serum immunoglobulin G4-negative type 1 autoimmune pancreatitis

Patients	Age/sex	Tissue	Image	OOI	Serum IgG4 (mg/dL)	Tissue IgG4 in HPF	Relapse
Case 1	72/F	Resection	Diffuse	No	75	5	No
Case 2	42/M	Resection	Diffuse	No	26	5	Yes
Case 3	71/F	Biopsy	Diffuse	RF	33	15	Yes
Case 4	61/M	Biopsy	Tail	No	39	11	No
Case 5	61/M	Resection	Body	No	43	80	No
Case 6	51/M	Resection	Tail	No	21	5	No
Case 7	66/M	Resection	Head	No	6	12	No
Case 8	53/F	Resection	Body	No	11	12	No

OOI: Other organ involvement; RF: Retroperitoneal fibrosis; HPF: High power field; F: Female; M: Male; IgG4: Immunoglobulin G4.