Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


PADI4 Haplotypes Do Not Interact with Smoking, but Interact with Shared Epitope Regardless of Antibodies to Cyclic Citrullinated Pepeptide

Bang1,  So-Young, Sung1,  Yoon-Kyoung, Jung1,  Kyounghee, Han2,  Tae-Un, Kang2,  Changwon, Bae1,  S.-C.

Hanyang Univ Medical Center, Seoul, South Korea
Korea Advanced Institute of Science and Technology(KAIST), Daejeon, South Korea

Purpose:

The association of the peptidyl arginine deiminase 4 (PADI4) gene with rheumatoid arthritis (RA) has been replicated in several Asian populations. Anti–cyclic citrullinated peptide antibodies (ACPA) are most specific serologic markers of RA. We investigated whether PADI4 polymorphisms contribute differently to two subsets of RA depending on the presence or absence of ACPA and whether PADI4 polymorphisms interact with the HLA-DRB1 shared epitope (SE) alleles or with smoking in a Korean population.

Method:

All RA patients (n =1313) and controls (n = 1009) were Korean. Four exonic SNPs of the PADI4 gene (padi4_89, padi4_90, padi4_92, and padi4_104) were genotyped using the MassArray SNP genotyping system. Odds ratios (OR) with 95% confidence intervals (CI) were examined using logistic regression analyses.

Results:

The four SNPs and functional haplotype of PADI4 gene were significantly associated with developing ACPA-positive RA and ACPA-negative RA. No interaction was seen between smoking and PADI4 polymorphisms. Gene-gene interactions between homozygous GTT haplotypes and SE alleles were observed in the development of ACPA-positive and ACPA-negative RA (attributable proportion 0.44 [95% CI 0.18–0.69], 0.57 [95% CI 0.22–0.91], respectively).

Conclusion:

Our findings indicate that PADI4 polymorphisms play a role in the development RA regardless of ACPA status. We could not find a gene-environment interaction between PADI4 polymorphisms and smoking. Gene-gene interaction between homozygous PADI4 haplotypes and SE alleles occurs in conferring an increased risk of ACPA-positive as well as ACPA-negative RA.

To cite this abstract, please use the following information:
Bang, So-Young, Sung, Yoon-Kyoung, Jung, Kyounghee, Han, Tae-Un, Kang, Changwon, Bae, S.-C.; PADI4 Haplotypes Do Not Interact with Smoking, but Interact with Shared Epitope Regardless of Antibodies to Cyclic Citrullinated Pepeptide [abstract]. Arthritis Rheum 2009;60 Suppl 10 :388
DOI: 10.1002/art.25471

Abstract Supplement

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