Relationship Between Polymorphisms of Interleukin-1 Receptor Antagonist (IL-1Ra) Genes and Susceptibility to Systemic Lupus Erythematosus in Iranian Population

Curr Rheumatol Rev. 2020;16(2):105-109. doi: 10.2174/1573397116666191218100556.

Abstract

Objectives: Interleukin (IL)-1 has a major role in cell destruction and inflammation. IL-1 receptor antagonist (IL-1RN or IL-1Ra) is a natural anti-inflammatory molecule that blocks IL-1. We intended to determine whether IL-1RN or IL-1Ra variable number tandem repeat (VNTR) polymorphism is associated with susceptibility to systemic lupus erythematosus (SLE) in a series of patients in the Northeastern part of Iran.

Methods: Genomic DNA was extracted from the whole blood of 104 SLE patients and 209 subjects without SLE as a control group. The control group was matched for age and gender with SLE patients. Then, genomic DNA was genotyped by polymerase chain reaction (PCR) method for a length polymorphism in intron 2 of the IL-1RN gene.

Results: Of five alleles, only allele 4 of IL-1RN had a higher frequency in healthy subjects (2.4%) compared to SLE patients (0), with a statistically significant difference (P= 0.03). Eleven kinds of polymorphisms of IL-1RN were found including 1/1, 1/2, 2/2, 3/3, 1/3, 3/5, 2/3, 2/5, 1/5, 4/4 and 1/4 in both groups. In genotype frequency, there was no statistically significant difference regarding gene polymorphism kinds between the two groups (P= 0.29).

Conclusion: Alleles 4 of IL-1RN may have a protective role against SLE susceptibility. However, SLE was not associated with any of the 11 kinds of genotype IL1-RN gene polymorphisms studied here.

Keywords: Systemic lupus erythematosus; antagonist; gene polymorphism; genes; interleukin-1; polymorphism; receptor..

MeSH terms

  • Adolescent
  • Adult
  • Alleles*
  • Cross-Sectional Studies
  • Female
  • Gene Frequency
  • Genetic Association Studies
  • Genetic Predisposition to Disease*
  • Genotype
  • Humans
  • Interleukin 1 Receptor Antagonist Protein / genetics*
  • Iran
  • Lupus Erythematosus, Systemic / genetics*
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide*
  • Young Adult

Substances

  • Interleukin 1 Receptor Antagonist Protein