OBJECTIVE: To examine the risk of anti-cyclic citrullinated peptide (anti-CCP) antibody positivity in rheumatoid arthritis (RA) patients carrying certain haplotypes in the HLA region. METHODS: A total of 1,389 Japanese patients with RA were genotyped for 30 single-nucleotide polymorphisms (SNPs) in the HLA region using commercial oligonucleotide arrays (from Perlegen or Affymetrix) as well as for HLA-DRB1 alleles using a sequence-specific polymerase chain reaction method. Stepwise logistic regression was used to select from among the 30 SNPs the ones that represented a risk of anti-CCP antibody positivity. Haplotypes of the selected SNPs were inferred using an expectation-maximization algorithm. Associations of individual SNPs were evaluated with the Cochran-Armitage test for trend. DRB1 alleles and haplotypes were evaluated with the chi-square test. Heterogeneities of risks among the shared epitope (SE) and non-SE HLA-DRB1 alleles were examined using the exact test. Haplotype associations that were independent of individual HLA-DRB1 alleles were evaluated using the likelihood ratio test. RESULTS: Significant associations were found for 9 SNPs (smallest P value being 2.4x10(-8)) and in 4 HLA-DRB1 alleles (smallest P value being 2.0x10(-10) in DRB1*0405). Stepwise logistic regression selected 4 SNPs (rs9262638, rs7775228, rs4713580, and rs9277359). Among the 16 inferred haplotypes of these 4 SNPs, 6 indicated significant associations (smallest P value being 1.9x10(-11)). Risks among SE and non-SE alleles were significantly heterogeneous (P=0.0095 and P=9.8x10(-9), respectively), indicating the importance of stratification with individual DRB1 alleles rather than SE alleles. Conditional analysis of the risk associated with individual DRB1 alleles identified a risk haplotype that was independent of DRB1 (odds ratio 2.00 [95% confidence interval 1.44-2.79], P=2.6x10(-5)). CONCLUSION: Heterogeneous risks of anti-CCP antibody positivity were confirmed among SE and non-SE alleles in our patient population. A risk haplotype in the HLA region that is independent of HLA-DRB1 was confirmed.
OBJECTIVE: To examine the risk of anti-cyclic citrullinated peptide (anti-CCP) antibody positivity in rheumatoid arthritis (RA) patients carrying certain haplotypes in the HLA region. METHODS: A total of 1,389 Japanese patients with RA were genotyped for 30 single-nucleotide polymorphisms (SNPs) in the HLA region using commercial oligonucleotide arrays (from Perlegen or Affymetrix) as well as for HLA-DRB1 alleles using a sequence-specific polymerase chain reaction method. Stepwise logistic regression was used to select from among the 30 SNPs the ones that represented a risk of anti-CCP antibody positivity. Haplotypes of the selected SNPs were inferred using an expectation-maximization algorithm. Associations of individual SNPs were evaluated with the Cochran-Armitage test for trend. DRB1 alleles and haplotypes were evaluated with the chi-square test. Heterogeneities of risks among the shared epitope (SE) and non-SE HLA-DRB1 alleles were examined using the exact test. Haplotype associations that were independent of individual HLA-DRB1 alleles were evaluated using the likelihood ratio test. RESULTS: Significant associations were found for 9 SNPs (smallest P value being 2.4x10(-8)) and in 4 HLA-DRB1 alleles (smallest P value being 2.0x10(-10) in DRB1*0405). Stepwise logistic regression selected 4 SNPs (rs9262638, rs7775228, rs4713580, and rs9277359). Among the 16 inferred haplotypes of these 4 SNPs, 6 indicated significant associations (smallest P value being 1.9x10(-11)). Risks among SE and non-SE alleles were significantly heterogeneous (P=0.0095 and P=9.8x10(-9), respectively), indicating the importance of stratification with individual DRB1 alleles rather than SE alleles. Conditional analysis of the risk associated with individual DRB1 alleles identified a risk haplotype that was independent of DRB1 (odds ratio 2.00 [95% confidence interval 1.44-2.79], P=2.6x10(-5)). CONCLUSION: Heterogeneous risks of anti-CCP antibody positivity were confirmed among SE and non-SE alleles in our patient population. A risk haplotype in the HLA region that is independent of HLA-DRB1 was confirmed.
Authors: Too Chun-Lai; Leonid Padyukov; Jasbir Singh Dhaliwal; Emeli Lundström; Abqariyah Yahya; Nor Asiah Muhamad; Lars Klareskog; Lars Alfredsson; Per Tobias Larsson; Shahnaz Murad Journal: PLoS One Date: 2011-06-15 Impact factor: 3.240
Authors: Pieter W A Meyer; Bridget Hodkinson; Mahmood Ally; Eustasius Musenge; Ahmed A Wadee; Heidi Fickl; Mohammed Tikly; Ronald Anderson Journal: Arthritis Res Ther Date: 2011-10-06 Impact factor: 5.156
Authors: Yukinori Okada; Kwangwoo Kim; Buhm Han; Nisha E Pillai; Rick T-H Ong; Woei-Yuh Saw; Ma Luo; Lei Jiang; Jian Yin; So-Young Bang; Hye-Soon Lee; Matthew A Brown; Sang-Cheol Bae; Huji Xu; Yik-Ying Teo; Paul I W de Bakker; Soumya Raychaudhuri Journal: Hum Mol Genet Date: 2014-07-28 Impact factor: 6.150