Strong association of common variants in the miRNA-binding site of NOD2 gene with clinicopathological characteristics and disease activity of systemic lupus erythematosus

Introduction/objectives Systemic lupus erythematosus (SLE) is a multifactorial systemic autoimmune disease, in which genetic susceptibility plays a pivotal role. The nucleotide oligomerization domain 2 (NOD2) gene is one of the main regulators of chronic inflammatory conditions and could be involved in SLE pathogenesis. Single nucleotide polymorphisms (SNPs) in miRNA binding sites which are located in 3'UTR of the NOD2 gene could be associated with SLE risk by dysregulation of NOD2 expression. In the present study, we assessed the possible association between SNPs rs3135500 and rs3135499 in the NOD2 gene with SLE risk in the Iranian population. Methods A case-control study using 110 SLE patients and 120 control subjects was undertaken to estimate rs3135500 (G > A) and rs3135499 (A > C) genotypes via real-time PCR high-resolution melting method (HRM). Results No significant association was observed between allele and genotype frequencies of rs3135500 and rs3135499 polymorphisms and SLE risk in this population (P > 0.05). However, there was an obvious association between rs3135500 (A allele) with laboratory factors that are associated with disease activity (P < 0.05) and some clinical manifestations that are associated with disease severity such as neurological symptoms, skin manifestations, renal involvements, and higher serum concentration of creatinine (P < 0.05). Besides, rs3135499 (C allele) was correlated with renal involvement and also the concentration of creatinine (P < 0.05). Moreover, in the patients group, the risk alleles in these polymorphisms were associated with lower age of onset (P < 0.05). Conclusions Our results suggest a substantial association between NOD2 polymorphisms with clinicopathological characteristics and SLE disease activity.

Automated summary

The study found no significant association between NOD2 gene polymorphisms rs3135500 and rs3135499 with SLE risk in the Iranian population. However, these polymorphisms were associated with laboratory factors related to disease activity and some clinical manifestations associated with disease severity.