Association Assessment of Peptidylarginine Deiminase Type 4 (PADI4) rs1748033 polymorphism and susceptibility to rheumatoid arthritis in Gorgan, Northeast of Iran

Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disease in which both genetic and environmental factors could be involved. Peptidyl arginine deiminase type IV (PADI4) is an enzyme responsible for the posttranslational conversion of arginine residues into citrulline. The association between PADI4 single nucleotide polymorphisms (SNPs) and RA susceptibility have been reported. Here, we aimed to assess the association of PADI4-104 (rs1748033) variant with the susceptibility to RA in an Iranian population in northeast of Iran. Materials and methods: A total of 130 RA patients and 128 age- and sex-matched healthy donors were recruited. The amplification-refractory mutation system with allele specific primers was used to detect PADI4-104 SNP. Disease activity was calculated using Disease Activity Scale 28a. SPSS 22.0 and SNPstat online software were used to analyze data using relevant statistical tests. Results: The CC genotype was more frequent in healthy subjects compared to RA patients. Setting the CC genotype as the reference, the TT genotype was significantly associated with increased risk of RA [OR = 2.11, 95% CI (1.45–3.07), P-value = 0.0001]. Moreover, no significant association was observed between genotypes and the disease activity score (P=0.154). Conclusions: The present study suggests that the PADI4-104 genetic variants are associated with RA susceptibility but not with the disease activity. While this is the first time to report such association in an Iranian population in northeast of Iran, further studies are required to confirm these findings