Interleukin-33 gene expression and rs1342326 polymorphism in Behcet's disease

Objective: Beheet's disease (BD) is a chronic multi-factorial inflammatory disease with the important role of genetic in activation of its inflammatory response. Interleukin (IL)-33 is a member of the IL-1 family of cytokines that affects innate and adaptive immune systems to promote inflammatory responses. In the current study, we investigated the association of IL-33 gene rs1342326 polymorphism and expression levels of this gene in peripheral blood mononuclear cells (PBMCs) with the susceptibility to BD in Azari population of Iran. Methods: We recruited 44 patients with BD and 61 age and sex-matched healthy controls in this cross-sectional study. The existence of rs1342326 T/G IL-33 gene single nucleotide polymorphism was investigated using Tetra Amplification Refractory Mutation System (Tetra-ARMS)-PCR. Allele and genotype distributions were evaluated among groups using chi-square or Fisher's test. Moreover, the mRNA levels of IL-33 in PBMCs were assessed through the Real-time PCR. Results: Patients with BD exhibited a significantly higher prevalence of the T/G genotype of rs1342326 polymorphism compared with the control group. Moreover, the expression level of IL-33 in PBMCs was significantly higher in the BD group compared to the healthy controls. Interestingly, the rs1342326 T/G polymorphism was associated with higher IL-33 expression in patients with BD. There was no association between the clinical manifestation of BD and disease activity with rs1342326 polymorphism and IL-33 expression. Conclusions: Our study implies that rs1342326 T/G polymorphism of the IL-33 gene may contribute to the genetic susceptibility to BD in part through regulation of the IL-33 expression.