Associations Between PADI4 Gene Polymorphisms and Rheumatoid Arthritis: An Updated Meta-analysis

Background and AimsStudies investigating the association between the peptidylarginine deiminase 4 (PADI4) gene polymorphisms and rheumatoid arthritis (RA) reported conflicting results. The aim of this meta-analysis was to assess the association between PADI4 gene polymorphisms and RA.MethodsA systematic literature search was conducted to identify relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of the association.ResultsA total of 34 studies from 28 articles involving 19859 patients with RA and 25771 healthy controls were included. Significant association of PADI4–94G/A polymorphism and RA was observed (OR = 0.891, 95% CI = 0.833–0.954, p = 0.001) in the overall study population and in the Asian populations (OR = 0.824, 95% CI = 0.759–0.894, p = 0.000) respectively. For the –92C/G polymorphism, a significant association was observed (OR = 1.481, 95% CI = 1.166–1.882, p = 0.001) in Africans. For the –90C/T polymorphism, a significant association was observed (OR = 0.576, 95% CI = 0.381–0.872, p = 0.009) in the Latin American population. The pooled estimates for the other polymorphisms were not statistically significantly associated with RA (PADI4–104C/T, –89A/G, –96T/C).ConclusionsThis meta-analysis demonstrates that PADI4–94G/A polymorphism is associated with susceptibility to RA in the overall population and in the Asian population. The PADI4 –92C/G polymorphism confers susceptibility to RA in Africans and the PADI4–90C/T polymorphism was associated with RA in the Latin American population.