Serological investigation of IgG and IgE antibodies against food antigens in patients with inflammatory bowel disease

Table 1 Clinical characteristics of all subjects, n (%)

Clinicopathological features	UC, n = 40	CD, n = 97	HCs, n = 50
Male	26 (65)	69 (71.13)	30 (60)
Female	14 (35)	28 (28.87)	20 (40)
Age in yr, mean ± SD	34.22 ± 12.50	33.51 ± 11.77	36.2 ± 10.73
Duration of disease in yr, mean, 95%CI	3.69 (2.12-4.86)	2.80 (2.01-3.54)	/
Disease activity
Remission	10 (25)	37 (38.14)	/
Mild	6 (15)	36 (37.11)	/
Moderate	17 (42.5)	23 (23.71)	/
Severe	7 (17.5)	1 (1.04)	/
Age at diagnosis in yr
A1, ≤ 16	/	6 (6.19)	/
A2, 17-40	/	67 (69.07)	/
A3, > 40	/	24 (24.74)	/
Disease location
L1, terminal ileum	/	41 (42.27)	/
L2, colon	/	17 (17.53)	/
L3, ileocolon	/	33 (34.02)	/
L1+L4	/	3 (3.09)	/
L3+L4	/	3 (3.09)	/
E1, rectum	10 (25)		/
E2, left-sided colon	7 (17.5)		/
E3, entire colon	23 (57.5)		/
Disease behaviour
B1, non-stricturing, non-penetrating		58 (59.79)	/
B2, stricturing		32 (32.98)	/
B3, penetrating		6 (6.19)	/
B2 + B3		1 (1.04)	/
CDAI, mean ± SD		153.96 ± 80.22
Mayo, mean ± SD	6.52 ± 3.24
Smoker	10 (25)	8 (8.25)	/
Perianal diseases	1 (2.5)	5 (5.15)	/
Medications
5-ASA	32 (80)	31 (31.96)	/
Sulfasalazine	2 (5)	/	/
Steroids	10 (25)	9 (9.28)	/
Immunosuppressive agents	2 (5)	19 (19.59)	/
Anti-TNF	/	32 (32.99)	/
Enteral nutrition	/	18 (18.56)
No meds	4 (10)	/	/
Surgery, IBD-related	2 (5)	30 (30.93)	/

E1, E2, E3: Disease location of UC using the Montreal Classification; A1, A2, A3: Age at diagnosis; L1, L2, L3: Disease location; B1, B2, B3, B2 + B3: Disease behavior of CD using the Montreal Classification; UC: Ulcerative colitis; CD: Crohn’s disease; HCs: Healthy controls; CDAI: Crohn’s Disease Activity Index; IBD: Inflammatory bowel disease.

Table 2 Percentage of positive food-specific IgG antibodies against 14 food items in ulcerative colitis patients, Crohn’s disease patients, and healthy controls

	CD	UC	HCs
Beef	0	0	0
Chicken	2.27	0	0
Codfish	13.64a	17.39	4.8
Corn	69.32c	47.83a	19
Crab	0	0	0
Egg	63.64	60.87	66.7
Mushroom	3.4	4.35	14.3
Milk	19.32	21.34	28.6
Pork	1.14	0	0
Rice	61.36c	26.09a	4.8
Shrimp	1.14	4.21	0
Soybean	46.59c	21.74	14.3
Tomato	80.68c	47.83c	4.8
Wheat	17.05b	8.7	0

Statistics: Chi-squared test

^aP < 0.05,

^bP < 0.01,

^cP < 0.001. UC: Ulcerative colitis; CD: Crohn’s disease; HCs: Healthy controls.

Table 3 Comparison of laboratory results between positive and negative food-specific IgG subgroups in inflammatory bowel disease patients

Laboratory results	sIgG (+)	sIgG (-)	P-value
	n = 111	n = 26
WBC, × 109/L	6.56 ± 2.57	6.26 ± 2.17	0.62
Hb, g/L	121.59 ± 23.72	123.71 ± 29.27	0.77
HCT	38.45 ± 6.38	37.36 ± 6.14	0.83
PLT, × 109/L	280.75 ± 110.31	233.65 ± 86.34	0.13
CRP, mg/L	17.27 ± 6.64	11.17 ± 4.84	0.13
ESR, mm/H	21.49 ± 19.88	20.12 ± 19.40	0.64
ALB, g/L	37.08 ± 5.24	40.21 ± 5.23	0.16

Data are expressed as mean ± SD: Student’s t test. No statistical significance (P > 0.05). WBC: White blood cell; Hb: Hemoglobin; PLT: Platelet; CRP: C-Reactive protein; ESR: erythrocyte sedimentation rate; HCT: Hematocrit; ALB: Albumin.

Table 4 Correlation between food-specific IgG and clinical parameters

Parameter	Odds ratio	95%CI	P-value
Disease type, UC/CD	12.48	3.45-45.09	0.000c
Gender, male/female	2.07	0.62-6.88	0.237
Age, < 40 yr/≥ 40 yr	0.44	0.14-1.41	0.167
Smoker	17.6	1.91-162.26	0.011a

UC: Ulcerative colitis; CD: Crohn’s disease; 95%CI: 95% Confidence interval. Statistics: Binary logistic regression,

^aP < 0.05,

^cP < 0.001. UC: Ulcerative colitis; CD: Crohn’s disease; IBD: Inflammatory bowel disease