PT - JOURNAL ARTICLE AU - Jinluo Cheng AU - Hui Zhang AU - Chao Zhuang AU - Ruiping Liu TI - Peptidylarginine Deiminase Type 4 and Methyl-CpG Binding Domain 4 Polymorphisms in Chinese Patients with Rheumatoid Arthritis AID - 10.3899/jrheum.120007 DP - 2012 Apr 15 TA - The Journal of Rheumatology PG - jrheum.120007 4099 - http://www.jrheum.org/content/early/2012/04/11/jrheum.120007.short 4100 - http://www.jrheum.org/content/early/2012/04/11/jrheum.120007.full AB - Objective Peptidylarginine deiminase type 4 (PADI4) and methyl-CpG binding domain 4 (MBD4) are closely related with rheumatoid arthritis (RA). We hypothesized that PADI4 and MBD4 polymorphisms may contribute to RA susceptibility. Methods We studied PADI4 rs2240340 G/A, PADI4 rs874881 C/G, MBD4 rs140693 G/A, and MBD4 rs2005618 T/C gene polymorphisms in 329 patients with RA and 697 controls in a Chinese population. Genotyping was done using matrix-assisted laser desorption/ionization time-of-flight mass spectro - metry (MALDI-TOF MS). Results When the PADI4 rs2240340 GG homozygote genotype was used as the reference group, the AA genotype was associated with a significantly increased risk of RA. In the recessive model, when PADI4 rs2240340 GG/GA genotypes were used as the reference group, the AA homozygote genotype was associated with a significant increased susceptibility to RA. PADI4 rs874881 C/G was in complete linkage disequilibrium with PADI4 rs2240340 G/A. MBD4 rs140693 G/A and MBD4 rs2005618 T/C polymorphisms were not associated with the risk of RA. In stratification analyses, a significantly increased risk for RA associated with the PADI4 rs2240340 AA genotype was evident among older patients and patients who were anticitrullinated protein antibody (ACPA)-positive compared with the PADI4 rs2240340 GG/GA genotype. Conclusion These findings suggest that the functional single-nucleotide polymorphism PADI4 rs2240340 G/A variant allele is associated with RA development, especially among older patients and ACPA-positive patients. However, our results were obtained from a moderate-sized sample, and therefore this is a preliminary conclusion. Validation by a larger study from a more diverse ethnic population is needed to confirm these findings.