Table 2.

 Serum antibodies to carbonic anhydrase IV by ELISA

Disease	n	N−/C−-CA IV positive (%)	CA IV peptide 4 positive (%)
AIP (definite)	15	4 (26.7)*	6 (40.0)***
AIP (probable)	14	6 (42.9)***	3 (21.4)**
ACP	15	2 (13.3)	2 (13.3)
Pancreatic cancer	14	2 (14.3)	1 (7.1)
Sjögren’s syndrome	20	9 (45.0)***	8 (40.0)***
Normal controls	26	0	0

AIP, autoimmune pancreatitis; ACP, alcoholic chronic pancreatitis; N⁻/C⁻-CA IV, truncated CA IV lacking both N terminal signal and C terminal glycosyl phosphatidylinositol anchored sequences; CA IV peptide 4, NH2-LGS LTT PTC DEK VVW TVF REP I-COOH (amino acid number 221–242).

*p<0.01, **p<0.02 ***p<0.001 compared with normal controls.