Association of Interleukin-1 Receptor Antagonist Gene 86bp VNTR Polymorphism with Systemic Lupus Erythematosus in South East of Iran

Background: systemic lupus erythematosus (sle) is an autoimmune disease with unknown etiology. interleukin-1 receptor antagonist (il-1ra) is naturally occurring cytokine that inhibits interleukin-1 (il-1) activity by binding to the il-1 receptors without signal transduction. the aim of this study was to investigate the association between il-1ra gene 86bp vntr polymorphism and systemic lupus erythematosus in the south- east of iran.materials and methods: in this case control study, genetic polymorphism was analyzed in 163 sle patients and 183 healthy controls. genotyping of il-1ra vntr polymorphism was determined by gel electrophoresis after pcr amplification.results: il-1ra vntr alleles have different copies of 86bp tandem repeats: allele 1 (four repeats), allele 2 (two repeats), allele 3 (five repeats), allele 4 (three repeats) and allele 5 (six repeats). we found an increased frequency of il-1ra allele 4 and 1/4 genotype in sle patients compared to healthy controls (p=0.001 and p=0.002 respectively). whereas, the frequency of il-1ra allele 3 was higher in controls than sle patients (p=0.01). there was no any association between the il-1ra allele 2 and sle. we did not observe any association between il-1ra polymorphism and sle manifestations.conclusion: we concluded that il-1ra allele 4 was involved in the pathogenesis of sle. however, there was no association between the il-1ra allele 2 and sle in south east of iran.