Serological profiling of Crohn’s disease and ulcerative colitis patients reveals anti-microbial antibody signatures

Table 1 Clinical information of the samples

	Discovery set			Validation set
	CD	UC	HC	CD	UC	HC
N	50	50	50	50	50	50
Gender (female, male)	29, 21	29, 21	29, 21	28, 22	28, 22	28, 22
Age (median ± SD)	41 ± 17.66	44 ± 17.25	42 ± 18.47	39.5 ± 17.49	44.5 ± 17.23	39.5 ± 16.02
Disease behavior (B1/B2/B3)	9/10/6			16/8/2
Disease location (L1/L2/L3/L4)	12/6/7/0			12/7/7/0
Disease extent (E1/E2/E3)		0/32/18			0/34/16
Surgery (Yes, No)	24, 25	8, 42		22, 27	7, 42

Fischer’s exact test P value is equal to 1 for the gender difference among CD, UC and HC in both discovery and validation set. Kruskal-Wallis test P value for the age difference among CD, UC and HC in discovery and validation set were 0.3159 and 0.1737 respectively. CD: Crohn’s disease; UC: Ulcerative colitis; HC: Healthy control.

Table 2 Sensitivities of validated IgG antibodies comparing Crohn’s disease and ulcerative colitis with healthy controls in the discovery, validation, and the entire set at 96% specificity

		Antigen	Protein name	Organism	Discovery	Validation	Entire
Crohn's disease	Bacteria	HP_0115	Flagellin B	H. pylori	28	48	38
		BVU_0562	Uncharacterized protein	B. vulgatus	26	22	25
		CK_LafA	Lateral flagellin	C. koseri	20	22	21
		CK_LafA.1	Lateral flagellin	C. koseri	16	26	24
		A4-Fla2	Flagellin	L. bacterium A4	40	54	47
		PMI_RS06815	Hypothetical protein	P. mirabilis	14	16	15
		VC_flaD	Flagellin	V. cholerae	24	18	19
		VC_flaB	Flagellin	V. cholerae	28	22	24
		VC_flaE	Flagellin	V. cholerae	26	28	23
		VC_flaA	Flagellin	V. cholerae	20	22	21
		SF_Lpp	Outer membrane lipoprotein	S. flexneri	14	18	14
		SP_1992	Cell wall surface anchor	S. pneumoniae	20	16	18
	Virus	BILF2	Glycoprotein BILF2	Human herpesvirus 4	18	18	18
Ulcerative colitis	Bacteria	CK_flgG	Flagellar basal-body rod protein	C. koseri	14	16	15
		A4-Fla2	Flagellin	L. bacterium A4	22	16	18
	Virus	BVRF2	Capsid scaffolding protein	Human herpesvirus 4	14	16	14
		UL139	Membrane glycoprotein UL139	Human herpesvirus 5	14	20	17

Table 3 Subgroup analysis of inflammatory bowel disease patients

Classification	Comparison	Number of antibodies with		Two sample proportion test
		OR > 1	OR < 1
Disease behavior: B1: non-stricturing, non-penetrating; B2: stricturing; B3: penetrating	B1 vs B2 (P < 0.05)	0	32	P < 0.001
	B2 vs B3 (P < 0.05)	0	19	P < 0.001
	B1 vs B3 (P < 0.05)	2	41	P < 0.001
Disease location: L1: ileal; L2: colonic; L3: ileocolonic	L1 vs L2 (P < 0.05)	0	38	P < 0.001
	L2 vs L3 (P < 0.05)	9	5	P = 0.131
	L1 vs L3 (P < 0.05)	5	16	P < 0.001
Disease extent: E2: left sided UC; E3: extensive UC	E2 vs E3 (P < 0.05)	11	39	P < 0.001
Surgery in CD patients	No vs Yes (P < 0.05)	6	25	P < 0.001

For each comparison, the number of antibodies with significant difference in prevalence between two classifications were counted based on odds ratio (OR) > 1 and OR < 1. The difference in total number of antibodies for each comparison were computed using two sample proportion test. CD: Crohn’s disease; UC: Ulcerative colitis; OR: Odds ratio.