RT Journal Article
SR Electronic
T1 Association study of <em>TRAF1-C5</em> polymorphisms with susceptibility to rheumatoid arthritis and systemic lupus erythematosus in Japanese
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 368
OP 373
DO 10.1136/ard.2008.104315
VO 69
IS 2
A1 K Nishimoto
A1 Y Kochi
A1 K Ikari
A1 K Yamamoto
A1 A Suzuki
A1 K Shimane
A1 Y Nakamura
A1 K Yano
A1 N Iikuni
A1 S Tsukahara
A1 N Kamatani
A1 H Okamoto
A1 H Kaneko
A1 Y Kawaguchi
A1 M Hara
A1 Y Toyama
A1 T Horiuchi
A1 K Tao
A1 K Yasutomo
A1 D Hamada
A1 N Yasui
A1 H Inoue
A1 M Itakura
A1 H Yamanaka
A1 S Momohara
YR 2010
UL http://ard.bmj.com/content/69/2/368.abstract
AB Objective: The primary aim of this study was to investigate the association of polymorphisms of TRAF1-C5, a newly identified rheumatoid arthritis (RA) risk locus in Caucasians, with susceptibility to RA and systemic lupus erythematosus (SLE) in Japanese populations. Gene expression levels of TRAF1 and C5 to assess the functional significance of genotypes were also analysed.Methods: A multicentre association study consisting of 4 RA case-control series (4397 cases and 2857 controls) and 3 SLE case-control series (591 cases and 2199 shared controls) was conducted. Genotyping was performed using TaqMan genotyping assay for two single nucleotide polymorphisms (SNPs) that showed the best evidence of association in the previous Caucasian studies. Quantifications of TRAF1 and C5 expression were performed with TaqMan expression assay.Results: Significant differences in allele frequency for both SNPs were observed between RA and control subjects (combined odds ratio  = 1.09), while no significant difference was detected between patients with SLE and controls. Interestingly, alleles rs3761847 A and rs10818488 G had increased the risk for RA in the present study, while they decreased the risk in the original studies. A significant difference was found between risk allele carriers and non-carriers of rs10818488 for the expression level of TRAF1 in phorbol myristate acetate-stimulated lymphoblastoid cell lines (p = 0.04).Conclusion: Association of TRAF1-C5 locus with RA susceptibility was detected in the Japanese populations with modest magnitude, while no significant association was observed for SLE. Significant positive effect of genotype on the expression of TRAF1 might support the genetic association between TRAF1 and RA.