Rheumatoid arthritis (RA) is the most common inflammatory disease which refers to bony erosions and joint destruction largely caused by genetic factors. Our study aimed to explore whether interleukin-7 receptor (IL-7R) gene polymorphisms influenced RA risk in the Han Chinese population.
Five single nucleotide polymorphisms (SNPs) in IL-7R gene were successfully genotyped using Agena MassARRAY platform. The associations between IL-7R polymorphisms and RA were evaluated by the Chi-squared test, T test, genetic model analysis, and haplotype analysis. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) using logistic regression analysis.
Rs969129 and rs6451231 in the IL-7R gene were associated with an increased risk of RA in the allele model (OR = 1.25, 95% CI = 1.05-1.49, p = 0.013; OR = 1.23, 95% CI = 1.03-1.48, p = 0.023), respectively. In the genetic models, rs969129 and rs6451231 were associated with an increased risk of RA. After stratification analysis by age, rs969129 and rs6451231 were associated with an increased risk of RA in patients (age <54). After stratification analysis by gender, rs6451231 was associated with an increased risk of RA in males, while rs969129 was found to be associated with an elevated risk of RA in females. And there was a strong linkage disequilibrium among the four SNPs (rs969129, rs118137916, rs10053847, and rs6451231).
These results suggested rs969129 and rs6451231 in the IL-7R gene were associated with an increased risk of RA in the Han Chinese population.