ERAP1 genetic variations associated with HLA-B27 interaction and disease severity of syndesmophytes formation in Taiwanese ankylosing spondylitis

Table 3 ERAP1 SNP analyses in normal controls and AS patients positive and negative for syndesmophyte

SNP /Group	RA /RAF	Genotype /Frequency			Trend test P**	Genotype analysis		Allelic analysis
						P	OR (95% CI)	P	OR (95% CI)
rs27037	T	GG	GT	TT			GT + TT vs. GG		T vs. G
Normal (N = 1150)	0.415	0.341	0.488	0.171	7 × 10^-5	2 × 10^-4	1.64 (1.27-2.14)	7.8 × 10^-5	1.39 (1.18-1.63)
AS Syn+ (N = 393)	0.496	0.239	0.529	0.232
AS Syn- (N = 403)	0.465	0.275	0.519	0.206	0.215	0.243	1.21 (0.88-1.66)	0.217	1.13 (0.93-1.38)
Adjusted for HLA-B27+*					0.338	0.449	1.13 (0.82-1.57)	0.351	1.10 (0.90-1.34)
rs27980	C	AA	AC CC				AC + CC vs. AA		C vs. A
Normal (N = 1150)	0.538	0.215	0.493	0.291	9.9 × 10^-3	0.011	1.49 (1.10-2.02)	9.4 × 10^-3	1.24 (1.05-1.46)
AS Syn+ (N = 393)	0.592	0.155	0.506	0.338
AS Syn- (N = 404)	0.555	0.191	0.510	0.300	0.134	0.188	1.28 (0.89-1.85)	0.134	1.16 (0.95-1.42)
Adjusted for HLA-B27+					0191	0.311	1.21 (0.83-1.77)	0.195	1.14 (0.93-1.40)
rs27044	G	CC	CG	GG			CG + GG vs. CC		G vs. C
Normal (N = 1149)	0.509	0.235	0.513	0.252	7 × 10^-5	10^-4	1.85 (1.35-2.53)	9.8 × 10^-5	1.38 (1.18-1.63)
AS Syn+ (N = 393)	0.589	0.143	0.537	0.321
AS Syn-(N = 403)	0.552	0.208	0.479	0.313	0.136	0.015	1.59 (1.33-2.30)	0.136	1.16 (0.95-1.42)
Adjusted for HLA-B27+					0.271	0.050	1.46 (1.00-2.13)	0.277	1.12 (0.91-1.37)
rs30187	T	CC	CT	TT			CT + TT vs. CC		T vs. C
Normal (N = 1150)	0.529	0.220	0.503	0.277	1.3 × 10^-3	3 × 10^-4	1.81 (1.31-2.50)	1.5 × 10^-3	1.31 (1.11-1.54)
AS Syn+ (N = 393)	0.594	0.135	0.542	0.323
AS Syn-(N = 404)	0.566	0.203	0.463	0.334	0.258	0.011	1.63 (1.12-2.38)	0.248	1.12 (0.92-1.37)
Adjusted for HLA-B27+					0.463	0.040	1.50 (1.02-2.20)	0.456	1.08 (0.88-1.32)

RA: Risk allele. RAF: Risk allele frequency. The case-control association tests were performed in two subsets of the samples: (1) AS patients with syndesmophyte (AS Syn+) vs. normal controls; (2) AS patients with syndesmophyte (AS Syn+) vs. AS patients without syndesmophyte (AS Syn-). *Cochran -Mantel -Haenszel (CMH) tests for ERAP1 SNP and syndesmophyte associations, controlling for HLA-B27 positivity. ** The Trend test p-values were generated from 100,000 permutations.

ISSN: 1478-6362