Single Immunoglobulin IL-1-Related Receptor (SIGIRR) Gene rs7396562 Polymorphism and Expression Level in Rheumatoid Arthritis.

OBJECTIVES

The aim of our study was to investigate the association of single-nucleotide polymorphism (SNP) and mRNA expression profile of () in rheumatoid arthritis (RA) in a Chinese population.

METHODS

polymorphism was genotyped using TaqMan allelic discrimination assay in 517 RA patients and 601 healthy controls. Simultaneously, the SIGIRR mRNA expression levels of 79 RA patients and 76 healthy controls were examined by real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

The frequency of T allele was significantly higher in RA patients compared with healthy controls (T versus G: OR = 1.277, 95%CI = 1.079 - 1.511, = 0.004). The TT genotype of rs7396562 was more frequent in RA patients than in healthy controls (OR = 1.547, 95%CI = 1.107 - 2.163, = 0.011). Moreover, we also found a significant difference in the recessive model (TT versus TG+GG: OR = 1.439, 95%CI = 1.122 - 1.847, = 0.004). However, no significant evidence was observed for the association of the with RA in dominant model (TT+TG versus GG: OR = 1.275, 95%CI = 0.947 - 1.717, = 0.109). Further analysis showed no association between polymorphism and laboratory parameters of RA patients (all > 0.05). The mRNA expression of SIGIRR was decreased in PBMCs of patients with RA when compared to healthy controls ( = -2.459, = 0.014). No significant differences in SIGIRR mRNA expression levels were observed in patients with RA with different genotypes ( = 0.280).

CONCLUSIONS

Our findings demonstrated that the dysregulation of SIGIRR might be associated with the pathogenesis of RA, and polymorphism might contribute to RA susceptibility in the Chinese population.