Association of a miRNA-binding site polymorphism in IL-16 gene with disease risk and clinical characteristics of rheumatoid arthritis and systemic lupus erythematosus

Introduction /objectives. Single nucleotide polymorphisms (SNPs) located at the 3′-UTR region of the target genes of microRNAs (miRNAs) can dysregulate their expression via disrupting the binding site of miRNAs. Interleukin-16 ( IL-16 ) is involved in the pathogenesis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). In the current study, we assessed the possible association between rs1131445 polymorphism in IL-16 gene with risk and clinical characteristics of RA and SLE in the Iranian population. Methods In this case–control study, 120 patients with RA, 120 patients with SLE, and 120 unrelated healthy subjects were collected to estimate rs1131445 (T > C) polymorphism in IL-16 gene using real-time PCR high-resolution melting (HRM) method. Results Our results demonstrated considerable associations between TC genotype and C allele of rs1131445 with enhanced risk of RA (OR for TC genotype = 3.01; 95%CI [1.667–5.526], P < 0.001; OR for C allele = 1.96; 95%CI [1.314–2.941], P < 0.001). Besides, there was a marginal association between CC genotype and increased risk of RA ( P : 0.031). However, there was an insignificant correlation between genotypes and allele frequencies of rs1131445 with incidence risk of SLE ( P > 0.05). Moreover, stratification analysis indicated that the C allele in rs1131445 was linked with disease activity–associated laboratory parameters such as CRP and ESR in both RA and SLE patients, as well as the higher incidence of neurological symptoms in SLE subjects ( P < 0.05). Conclusion These results proposed a significant association between IL-16 polymorphism and augmented risk of RA and clinical characteristics of RA and SLE. Key Points • Single nucleotide polymorphism (rs1131445) in miRNA -binding sites which is located in 3′ˊUTR of the IL-16 gene could be associated with RA and SLE risk by dysregulation of IL-16 expression. • Our findings proposed a significant association between IL-16 polymorphism and augmented risk of RA and clinical characteristics of RA and SLE