A functional microRNA binding site variant in <i>IL-23R</i> gene in systemic lupus erythematosus and rheumatoid arthritis: is there any correlation?

Abstract

Background IL-23 receptor (IL-23R) dysregulation has been shown to have critical roles in pathogenesis of different autoimmune diseases including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) via suppression of regulatory T cells (Tregs) as well as differentiation, expansion, and survival of T helper 17 (Th17) cells, followed by upregulation of interleukin 17 (IL-17). Here, we assessed the association of a functional microRNAs (miRNAs)-related single nucleotide polymorphism (miR-SNPs: rs10889677) in IL-23R, which was correlated with its overexpression and increased risk for SLE and RA in the Iranian population. Methods Genotype and allele distribution of rs10889677 variant were investigated in 105 RA patients, 100 SLE cases and 105 healthy controls via polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) method. Results Our findings suggested that AA genotype, but not AC genotype, was associated with increased risk of RA (AA vs. CC; OR: 3.27; 95CI 1.467-7.551). The allele A was more frequent in RA group compared to controls (A allele vs. C allele; OR: 1.92; 95%CI 1.282-2.894). This common variant was not significantly correlated with SLE risk in our population (P > 0.05). However, stratification analysis indicated that RA patients with AA genotype show higher serum concentration levels of C-reactive protein (CRP) (P: 0.008). No obvious correlation was noticed between different genotypes in SLE cases, except for a slight difference in terms of oral ulcer manifestation incidence (P: 0.038). Conclusion This study suggests a significant relationship between rs10889677 variant in IL-23R with increased risk of RA and some clinical features in RA and SLE patients.