1. The Combined Measurement of Total Serum IgG and IgG4 May Increase Diagnostic Sensitivity for Autoimmune Pancreatitis Without Sacrificing Specificity, Compared With IgG4 Alone
Tae Jun Song , MD1 , Myung-Hwan Kim , MD , PhD1 , Sung-Hoon Moon , MD1 , Jun Bum Eum , MD1 , Do Hyun Park , MD , PhD1 ,Sang Soo Lee , MD , PhD 1 , Dong Wan Seo , MD , PhD1 and S ung Koo Lee , MD, PhD1
Am J Gastroenterol 2010;105:1655–1660
R3. Chung Hoehoon / Prof. Dong Seokho

2. Introduction Autoimmune pancreatitis (AIP) Japanese criteria
Increasingly being recognized to be a worldwide entity
Lack of a simple diagnostic test
No international consensus on AIP
Japanese criteria
In 2002, the Japan Pancreas Society first proposed
Based on the use of imaging, serology, and histology
Serological criteria included elevated titers of γ –globulin, IgG, autoantibodies .
In 2006, immunoglobulin (Ig) G4 was newly added

3. Asian diagnostic criteria
Proposed by a consensus of Japanese and Korean pancreatologists
γ -globulin was deleted from serological criteria
HISORt criteria
Serum IgG4 alone
The principal aim of this study
To find whether combined measurement of total serum IgG and IgG4
could increase diagnostic sensitivity for AIP while maintaining specificity
To determine the utility of autoantibodies in diagnosing AIP

4. Methods
AIP group
Approved by the Institutional Review Board of Asan Medical Center
January 2003 ~ June 2009
82 patients
Prospectively collected
Total serum IgG and IgG4
ANA and RF be assayed
All patients fulfilled
: Asian diagnostic criteria or
: HISORt criteria

5. As a comparison group
110 patients with pancreatic cancer were enrolled
January 2008 ~ June 2009
prospectively collected
total serum IgG and IgG4 were measured
Diagnosis : confirmed by pancreatic histology and / or cytology

6. Interpretation of serological testing
Estimated the sensitivity and specificity of total serum IgG and IgG4
: diagnosis and differentiation of AIP from pancreatic cancer
Cutoff value by the Japan Pancreas Society
: total IgG ≥ 1800 mg / dl
IgG4 ≥ 135 mg / dl
Seropositivity for combined measurement of total serum IgG and IgG4
: elevation of either total IgG or IgG4.
Seropositivity of ANA
: elevation of titer more than 1:80

7. Results

8. Clinical findings

9. Sensitivity of individual tests
P<0.05
P=0.125

10. Sensitivity of combined measurements

11. Specificity of individual tests
Figure 1. The distribution of total serum immunoglobulin (Ig) G concentrations
( a ) and serum IgG4 concentrations ( b ) in 82 patients with autoimmune pancreatitis (AIP) and 110 patients with pancreatic cancer.

12. Conclusion The combined measurement of total serum IgG and IgG4
may increase diagnostic sensitivity without sacrificing
specificity, compared with IgG4 alone.
The measurement of ANA or RF may show no additional benefit when combined with total serum IgG and IgG4.