Association between the single nucleotide variants of IRAK1 and CCR6 gene and the susceptibility to rheumatoid arthritis: a case–control study

Rheumatoid arthritis pathogenesis involves multifaceted genetic and environmental interactions, with hereditary components contributing 50 to 60% of disease susceptibility. Among non-HLA genetic determinants, polymorphisms in Interleukin-1 receptor (IL-1R)-associated kinase (IRAK1) and Chemokine receptor type 6 (CCR6) genes potentiate vulnerability to autoimmune diseases. So, this research aims at examining the potential role of the single nucleotide variant of IRAK1 and CCR6 genes in RA vulnerability and clarifying their association with disease-related variables. 58 RA cases and 40 healthy controls were recruited. We performed genotyping for IRAK1 rs1059703 via restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) and CCR6 rs3093024 using amplification-refractory mutation system PCR (ARMS-PCR) methodology. Statistical analysis demonstrated significant associations for IRAK1 CT + TT vs CC genotypes (P = 0.012) and T allele frequency (P = 0.001) differed substantially between RA patients and healthy controls. Conversely, CCR6 genotype/allele distributions showed no significant intergroup variations. Clinical parameters, including age, disease duration, sex, subcutaneous nodules, interstitial lung disease, Sjogrenʼs syndrome, joint deformity and rheumatoid factor (RF), demonstrated no significant association with either IRAK1 or CCR6 genotypes with exception of a significant link between CCR6 genotypes and anti-CCP positivity (P = 0.049). The presence of the polymorphic genotypes and T allele of IRAK1 gene is associated with increased susceptibility of RA. Variation in CCR6 genotype was not associated with RA. However, the polymorphic variant of CCR6 was associated with positive anti-CCP. Assessing the relationship between RA pathogenesis and additional SNPs in these genes is advised.