Gastroenterol Res

Gastroenterology Research, ISSN 1918-2805 print, 1918-2813 online, Open Access

Article copyright, the authors; Journal compilation copyright, Gastroenterol Res and Elmer Press Inc

Journal website http://www.gastrores.org

Original Article

Volume 8, Number 2, April 2015, pages 178-185

Can IgG4 Levels Identify the Ulcerative Colitis Subtype of Inflammatory Bowel Disease?

Figure 1. Box plots showing the distribution of IgG4 levels (in mg/dL) in patients with ulcerative colitis (UC) and Crohn’s disease (CD). The median IgG4 level was 50 mg/dL in the UC group and 46 mg/dL in the CD group. IgG4 levels > 140 mg/dL were significantly more prevalent in patients with UC (P = 0.0006). The line represents the 140 mg/dL cutoff.

Figure 2. Box plots showing the distribution of fecal pancreatic elastase levels (in μg/g of stool) in patients with ulcerative colitis (UC) and Crohn’s disease (CD). The median elastase level was 391 μg/g in the UC group and 301 μg/g in the CD group. There was no significant between-group difference in the prevalence of levels < 200 μg/g (P = 0.7).

Figure 3. Flowchart of patients with inflammatory bowel disease and abnormal laboratory findings (IgG4/elastase) among those for whom immunohistochemical assessment of tissue IgG4 levels was available. N: number of patients; HPF: high-power field.

**Table 1.** Clinical and Epidemiologic Profile of Patients With Inflammatory Bowel Disease (n = 56)
Variable	UC^a (n = 30)	CD^b (n = 26)	Overall (n = 56)
^aUlcerative colitis. ^bCrohn’s disease. ^cMean (standard deviation). ^dNumber of patients with fecal elastase level < 200 μg/g of stool. ^eNumber of patients with serum IgG4 level > 140 mg/dL. ^fNumber of patients with active disease as defined by the Lichtiger clinical-activity index (UC) or the Crohn’s disease activity index (CD).
Females	19	16	35
Age (years)^c	42 (14)	44 (15)	43 (14)
Reduced fecal elastase^d	5	5	10
Elevated serum IgG4^e	9	1	10
Active disease^f	14	8	22
Extraintestinal manifestations	3	0	3
Time elapsed since diagnosis (months)^c	67 (71)	69 (46)	68 (61)

Table 1. Clinical and Epidemiologic Profile of Patients With Inflammatory Bowel Disease (n = 56)

Variable

UC^a (n = 30)

CD^b (n = 26)

Overall (n = 56)

^aUlcerative colitis. ^bCrohn’s disease. ^cMean (standard deviation). ^dNumber of patients with fecal elastase level < 200 μg/g of stool. ^eNumber of patients with serum IgG4 level > 140 mg/dL. ^fNumber of patients with active disease as defined by the Lichtiger clinical-activity index (UC) or the Crohn’s disease activity index (CD).

Females

Age (years)^c

42 (14)

44 (15)

43 (14)

Reduced fecal elastase^d

Elevated serum IgG4^e

Active disease^f

Extraintestinal manifestations

Time elapsed since diagnosis (months)^c

67 (71)

69 (46)

68 (61)

**Table 2.** Extent (Location and Behavior) of Crohn’s Disease According to the Montreal Classification (n = 26)
Variable	n
^aGastrointestinal.
Location
Ileal	6
Colonic	19
Ileocolonic	1
Upper GI^a tract	0
Perianal	0
Behavior
Non-stricturing, non-penetrating	14
Stricturing	6
Penetrating	6

Table 2. Extent (Location and Behavior) of Crohn’s Disease According to the Montreal Classification (n = 26)

Variable

^aGastrointestinal.

Location

Ileal

Colonic

Ileocolonic

Upper GI^a tract

Perianal

Behavior

Non-stricturing, non-penetrating

Stricturing

Penetrating

**Table 3.** Association Between Sociodemographic and Clinical Variables and Serum IgG4 > 140 mg/dL in Patients With Inflammatory Bowel Disease and Prevalence Ratios After Multiple Poisson Regression
	n (%)	Prevalence, n (%)	95% CI	PR^a	95% CI^b	P-value
^aPrevalence ratio (multiple Poisson regression). ^b95% confidence interval, corrected (multiple Poisson regression). ^cUlcerative colitis. ^dCrohn’s disease.
Sex
Male	21 (37%)	6 (28.57%)	8.64 - 48.51	1.00
Female	35 (63%)	4 (11.43%)	0.55 - 22.3	1.89	0.63 - 5.63	0.2000
Disease
UC^c	30 (53.5%)	9 (30%)	13.08 - 46.92	16.42	3.32 - 79.58	0.0006
CD^d	26 (46.4%)	1 (3.85%)	0.00 - 11.47	1.00
Activity
Remission	37 (66%)	6 (16.22%)	3.96 - 28.47	1.01	0.31 - 3.35	0.9000
Active	19 (33%)	4 (21.05%)	2.14 - 39.97	1.00
Elastase
> 200 μg/g	46 (82.2%)	8 (17.39%)	6.09 - 28.69	1.00
< 200 μg/g	10 (17.8%)	2 (20.0%)	0.00 - 45.58	0.74	0.18 - 3.02	0.7000
Azathioprine
No	23 (41%)	3 (13.04%)	0.00 - 27.74	1
Yes	33 (59%)	7 (21.21%)	6.82 - 35.6	4.8	1.32 - 17.39	0.0017
Corticosteroids
No	25 (40%)	5 (20%)	3.82 - 36.18	3.86	1.01 - 14.65	0.0470
Yes	31 (60%)	5 (16%)	2.77 - 29.49	1

Table 3. Association Between Sociodemographic and Clinical Variables and Serum IgG4 > 140 mg/dL in Patients With Inflammatory Bowel Disease and Prevalence Ratios After Multiple Poisson Regression

n (%)

Prevalence, n (%)

95% CI

PR^a

95% CI^b

P-value

^aPrevalence ratio (multiple Poisson regression). ^b95% confidence interval, corrected (multiple Poisson regression). ^cUlcerative colitis. ^dCrohn’s disease.

Sex

Male

21 (37%)

6 (28.57%)

8.64 - 48.51

1.00

Female

35 (63%)

4 (11.43%)

0.55 - 22.3

1.89

0.63 - 5.63

0.2000

Disease

UC^c

30 (53.5%)

9 (30%)

13.08 - 46.92

16.42

3.32 - 79.58

0.0006

CD^d

26 (46.4%)

1 (3.85%)

0.00 - 11.47

1.00

Activity

Remission

37 (66%)

6 (16.22%)

3.96 - 28.47

1.01

0.31 - 3.35

0.9000

Active

19 (33%)

4 (21.05%)

2.14 - 39.97

1.00

Elastase

> 200 μg/g

46 (82.2%)

8 (17.39%)

6.09 - 28.69

1.00

< 200 μg/g

10 (17.8%)

2 (20.0%)

0.00 - 45.58

0.74

0.18 - 3.02

0.7000

Azathioprine

23 (41%)

3 (13.04%)

0.00 - 27.74

Yes

33 (59%)

7 (21.21%)

6.82 - 35.6

4.8

1.32 - 17.39

0.0017

Corticosteroids

25 (40%)

5 (20%)

3.82 - 36.18

3.86

1.01 - 14.65

0.0470

Yes

31 (60%)

5 (16%)

2.77 - 29.49

**Table 4.** Association Between Sociodemographic and Clinical Variables and Fecal Elastase < 200 μg/g in Patients With Inflammatory Bowel Disease and Prevalence Ratios After Multiple Poisson Regression
	n (%)	Prevalence, n (%)	95% CI	PR^a	95% CI^b	P-value
^aPrevalence ratio (multiple Poisson regression). ^b95% confidence interval, corrected (multiple Poisson regression). ^cUlcerative colitis. ^dCrohn’s disease.
Sex
Male	21 (37%)	4 (19%)	1.72 - 36.38	1.26	0.39 - 4.06	0.7000
Female	35 (63%)	6 (17%)	4.26 - 30.02	1.00
Disease
UC^c	30 (53.5%)	5 (16.67%)	2.91 - 30.43	1.00
CD^d	26 (46.4%)	5 (19.23%)	3.60 - 34.86	1.25	0.22 - 7.19	0.8000
Activity
Remission	37 (66%)	7 (18.92%)	5.9 - 31.94	1.16	0.33 - 4.16	0.8000
Active	19 (33%)	3 (15.79%)	0.00 - 32.71	1.00
IgG4
> 140 mg/dL	10 (17.8%)	2 (20%)	0.00 - 45.58	1.23	0.21 - 7.15	0.8000
< 140 mg/dL	46 (82.2%)	8 (17.39%)	6.09 - 28.69	1.00
Azathioprine
No	23 (41%)	4 (17.39%)	1.41 - 33.37	1
Yes	33 (59%)	6 (21.21%)	4.60 - 31.76	1.18	0.24 - 5.93	0.8000
Corticosteroids
No	25 (40%)	5 (20%)	3.82 - 36.18	1.00
Yes	31 (60%)	5 (16.13%)	2.77 - 29.49	1.04	0.23 - 4.73	0.9000

Table 4. Association Between Sociodemographic and Clinical Variables and Fecal Elastase < 200 μg/g in Patients With Inflammatory Bowel Disease and Prevalence Ratios After Multiple Poisson Regression

n (%)

Prevalence, n (%)

95% CI

PR^a

95% CI^b

P-value

^aPrevalence ratio (multiple Poisson regression). ^b95% confidence interval, corrected (multiple Poisson regression). ^cUlcerative colitis. ^dCrohn’s disease.

Sex

Male

21 (37%)

4 (19%)

1.72 - 36.38

1.26

0.39 - 4.06

0.7000

Female

35 (63%)

6 (17%)

4.26 - 30.02

1.00

Disease

UC^c

30 (53.5%)

5 (16.67%)

2.91 - 30.43

1.00

CD^d

26 (46.4%)

5 (19.23%)

3.60 - 34.86

1.25

0.22 - 7.19

0.8000

Activity

Remission

37 (66%)

7 (18.92%)

5.9 - 31.94

1.16

0.33 - 4.16

0.8000

Active

19 (33%)

3 (15.79%)

0.00 - 32.71

1.00

IgG4

> 140 mg/dL

10 (17.8%)

2 (20%)

0.00 - 45.58

1.23

0.21 - 7.15

0.8000

< 140 mg/dL

46 (82.2%)

8 (17.39%)

6.09 - 28.69

1.00

Azathioprine

23 (41%)

4 (17.39%)

1.41 - 33.37

Yes

33 (59%)

6 (21.21%)

4.60 - 31.76

1.18

0.24 - 5.93

0.8000

Corticosteroids

25 (40%)

5 (20%)

3.82 - 36.18

1.00

Yes

31 (60%)

5 (16.13%)

2.77 - 29.49

1.04

0.23 - 4.73

0.9000