Association of polymorphisms in SPARC and NLRP2 genes with rheumatoid arthritis in a Chinese Han population.

OBJECTIVES: To investigate the association of the polymorphisms in SPARC and NLRP2 with rheumatoid arthritis (RA) in a Chinese Han population. METHODS: Four single nucleotide polymorphisms (SNPs) covering SPARC and three SNPs covering NLRP2 were investigated in 624 Chinese Han RA patients and 1920 healthy controls. RESULTS: The A allele at SPARC rs3210714, SPARC rs11950384, NLRP2 rs2217659, and NLRP2 rs703468 were linked to reduced risk of RA (p = 0.0016, p = 0.0051, p < 0.0001, and p = 0.0033, respectively). Under the recessive model, the A/A genotype of rs3210714, rs11950384, rs2217659, and rs703468 were relevant with RA (p = 0.0071, p = 0.017, p < 0.0001 and p = 0.0066, respectively). Haplotype analysis identified the SPARC GGCG haplotype, AAAA haplotype were associated with the risk for RA (p < 0.0001 and p = 0.0015, respectively), while the risk of RA was lower for carriers of the GAAA haplotype (p < 0.0001), AACG haplotype (p < 0.0001), and the AGCG haplotype (p < 0.0001). The NLRP2 GG haplotype was a risk factor (p < 0.0001), while the GA haplotype and the AG haplotype were associated with lower risk of RA (p < 0.0001 and p = 0.0017, respectively). There was no significant difference between the RA patients and the controls in polymorphisms of rs7719521, rs1978707, and rs269913. CONCLUSION: This study indicates that polymorphisms in SPARC and NLRP2 are related to RA susceptibility in a Chinese Han population.

Association Between SPARC Polymorphisms and Ankylosing Spondylitis and Its mRNA and Protein Expression in a Chinese Han Population: A Case-Control Study.

Objective: We explore the association of polymorphisms in Secreted protein acidic and rich in cysteine (SPARC) with ankylosing spondylitis (AS) and detect SPARC mRNA and protein expression in a Chinese Han population. Methods: Nine single-nucleotide polymorphisms (SNPs) of SPARC were genotyped in 768 AS patients and 768 controls by TaqMan genotyping assay. mRNA expression of SPARC was detected by real-time polymerase chain reaction (RT-PCR), and serum level of SPARC protein was detected by ELISA. Results: The frequency of A allele of rs171121187 was significantly higher in AS patients than in controls (Pc=0.003, odds ratio [OR]=1.45, 95% confidence interval [95% CI] = 1.18-1.77), the AA and AC genotypes increased the risk of AS when compared with CC genotype (Pc=0.003, OR=3.96, 95% CI=1.80-8.75, and Pc=0.003, OR=1.27, 95% CI=1.01-1.61, respectively). The frequency of G allele of rs4958487 was significantly lower in AS than in controls (Pc=0.001, OR=0.60, 95% CI=0.47-0.68), the GG and GA genotypes reduced the risk of AS when compared with AA genotype (Pc=0.005, OR=0.46, 95% CI 0.18-1.14, and Pc=0.005, OR=0.60, 95% CI=0.45-0.79, respectively). The haplotype AA of rs17112187/rs4958487 significantly increased the risk of AS (P=2.31E-5, OR=1.60, 95% CI=1.28-1.98), while haplotype CG decreased the risk of AS (P=5.42E-5, OR=0.55, 95% CI=0.41-0.74). Expression levels of SPARC mRNA were significantly lower in both Peripheral blood mononuclear cells (PBMC) and granulocytes in AS patients than in controls (P=0.008 and P=0.005, respectively). SPARC protein levels were also reduced in AS patients versus the controls (P=0.002). Conclusion: This study indicates that polymorphisms in SPARC are associated with AS susceptibility, and both mRNA and protein levels of SPARC are decreased in AS patients in a Chinese Han population.

Association of KIF21B genetic polymorphisms with ankylosing spondylitis in a Chinese Han population of Shandong Province.

Previous studies have found that the kinesin family member (KIF) 21B may contribute to the autoimmune disease process. It has been reported that the KIF21B gene is relevant to the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC). We hypothesized that KIF21B might be a key gene for ankylosing spondylitis (AS) development. To test this hypothesis, 11 tag single nucleotide polymorphisms (SNPs) covering KIF21B were investigated in 904 Chinese (Han ethnic) patients of Shandong Province with AS and 898 age- and sex-matched controls of the same ethnic origin. The T allele of rs756254 was linked to increased risk of AS (P = 0.022). The AA genotype of rs296560 and TT and AT genotypes of rs756254 were also relevant with AS (P = 0.044, P = 0.033, and P = 0.033, respectively). Haplotype analysis identified that the KIF21B gene region contains two haplotype blocks of eight and two SNPs, respectively. The haplotype GCGGTAAA in block 1 appeared to reduce the risk of AS (P = 0.005), while the haplotype AA in block 2 was significantly associated with an increased risk of AS (P = 0.039). There were no significant differences between the AS patients and the controls in polymorphisms of rs10920091, rs3198583, rs56368827, rs3738255, rs296565, rs12087649, rs12568529, rs7536000, and rs957957. These results indicated that KIF21B was associated with AS in a Chinese population of Shandong Province.