Associations between CD24 gene polymorphisms and inflammatory bowel disease: A meta-analysis

Table 1 Characteristics of the studies included in the meta-analysis

First author	Year	Country	Ethnicity	Sample size			Polymorphisms	Genotype
				UC	CD	Control		method
Diaz-Gallo LM	2011	Spain	Caucasian	632	737	1257	P170 P1527	PCR
Van Limbergen	2013	Scottish	Caucasian	342	395	498	P1527	PCR
Lisiansky V	2014	Israel	Caucasian	174	62	210	P170 P1527	PCR-RFLP

UC: Ulcerative colitis; CD: Crohn’s disease; RFLP: Restricted fragment length polymorphisms; PCR: Polymerase chain reaction.

Table 2 Distributions of two CD24 genotypes and alleles among the inflammatory bowel disease patients and controls

Study	Arms	C170T						Arms	TG1570del
		A	V	AA	AV	VV	HWE		TG	del	TGTG	TGdel	deldel	HWE
Diaz-Gallo et al[26], 2011	CD (n = 366)	534	198	200	134	32		CD (n = 371)	662	80	301	60	10
	UC (n = 322)	448	196	161	126	35		UC (n = 310)	580	40	270	40	0
	Control (n = 628)	904	352	317	270	41	0.100	Control (n = 629)	1170	88	547	76	6	0.448
Lisiansky et al[25], 2014	CD (n = 31)	42	20	12	18	1		CD (n = 31)	57	5	26	5	0
	UC (n = 87)	108	66	29	50	8		UC (n = 87)	165	9	78	9	0
	Control (n = 105)	163	47	63	37	5	0.884	Control (n = 105)	198	12	93	12	0	0.534
Van Limbergen et al[27], 2013	CD (n = 395)	-	-	-	-	-			719	71	326	67	2
	UC (n = 310)	-	-	-	-	-			623	61	283	57	2
	Control (n = 498)	-	-	-	-	-			905	91	411	83	4	0.932

UC: Ulcerative colitis; CD: Crohn’s disease; HWE: Hardy-Weinberg equilibrium.

Table 3 Meta-analysis of the associations between two promoter polymorphisms of CD24 and inflammatory bowel disease

Polymorphism	Disease	Test of association			Test of heterogeneity
		OR	95%CI	P value	Model	P value	I2(%)
P170V vs A	CD	1.16	0.69-1.93	0.583	R	0.100	63.0
	UC	1.49	0.81-2.77	0.203	R	0.012	84.3
	IBD	1.39	0.73-2.64	0.314	R	0.004	87.7
VV + AV vs AA	CD	0.76	0.28-2.07	0.594	R	0.019	81.9
(recessive)	UC	0.59	0.21-1.70	0.330	R	0.001	90.5
	IBD	0.64	0.21-1.90	0.420	R	< 0.001	92.8
VV vs AA + AV	CD	1.32	0.83-2.11	0.245	F	0.527	0.0
(dominant)	UC	1.79	1.15-2.77	0.009	F	0.816	0.0
	IBD	0.94	0.62-1.43	0.777	F	0.287	11.8
VV vs AA	CD	1.23	0.76-1.99	0.405	F	0.888	0.0
(additive)	UC	1.87	1.19-2.93	0.007	F	0.272	17.1
	IBD	1.32	0.40-4.39	0.654	R	0.051	73.9
P1527del vs TG	CD	1.24	1.01-1.52	0.037	F	0.101	56.5
	UC	0.95	0.76-1.19	0.649	F	0.967	0.0
	IBD	1.18	0.99-1.41	0.063	F	0.803	0.0
deldel + TGdel vs TGTG	CD	0.80	0.63-1.02	0.068	F	0.207	36.5
(recessive)	UC	1.02	0.79-1.33	0.870	F	0.980	0.0
	IBD	0.82	0.67-1.01	0.061	F	0.870	0.0
deldel vs TGTG + TGdel	CD	1.87	0.81-4.32	0.143	F	0.133	55.7
(dominant)	UC	0.40	0.10-1.63	0.201	F	0.345	0.0
	IBD	1.23	0.54-2.76	0.625	F	0.436	0.0
deldel vs TGTG	CD	1.93	0.84-4.47	0.123	F	0.121	58.4
(additive)	UC	0.40	0.10-1.64	0.203	F	0.348	0.0
	IBD	1.27	0.56-2.86	0.572	F	0.439	0.0

IBD: Inflammatory bowel disease; UC: Ulcerative colitis; CD: Crohn’s disease.

Table 4 Egger’s tests for C170 T and TG1527del of CD24 and the inflammatory bowel disease risk in all of the included studies

Contrast models	Coefficient	95%CI	SE	t	P value
C170T
V vs A	3.902	0.912 to 6.891	1.077	3.62	0.022
VV +AV vs AA	-4.527	-5.832 to 3.075	1.969	-0.70	0.501
VV vs AA + AV	0.200	-7.276 to -1.779	0.990	-4.57	0.010
VV vs AA	1.399	-2.040 to 4.838	1.239	1.13	0.322
TG1527del
del vs TG	-0.435	-2.669 to 1.799	0.945	-0.46	0.659
deldel + TGdel vs TGTG	0.444	-1.833 to 2.721	0.963	0.64	0.659
deldel vs TGTG + TGdel	-2.977	-4.820 to -1.134	0.664	-4.48	0.011
deldel vs TGTG	-2.598	-4.249 to -0.947	0.595	-4.37	0.012

IBD: Inflammatory bowel disease; UC: Ulcerative colitis; CD: Crohn’s disease.