Association between IL-33 Gene Polymorphism (Rs7044343) and Risk of Allergic Rhinitis.

Background: Allergic rhinitis (AR) is a T helper type 2 (Th2)-mediated upper airways disease in which genetics factors including cytokine genes play a prominent role. Interleukin-33 (IL-33) is a major cytokine for naive T cells polarization into Th2 phenotype as well as enhances the secretion of Th2 cytokines. The aim of the present study was to investigate the relationship between IL-33 single nucleotide polymorphisms (SNPs) and IL-33 serum level with Allergic rhinitis.

Methods: Blood samples were collected from 130 AR patients and 130 healthy individuals. SNPs (rs7044343 C > T, rs1929992 A > G, rs12551256 A > G) of IL-33 gene were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum level of IL-33 was measured by enzyme-linked immunosorbent assay (ELISA).

Results: Statistical analysis showed that the TT genotype (OR = 1.996, CI: 1.168-3.412, = .01), as well as the T allele (OR = 0.675, CI: 0.476-0.957, = .02) of rs7044343 C > T were significantly associated with reduced risk of AR. In addition, individuals carrying the TT genotype were associated with lower levels of IL-33 compared to subjects with CC and CT genotypes; however, these differences were not statistically significant. No association was found between rs1929992 and rs12551256 variants and risk of AR, but the GG genotype from rs1929992 A > G was associated with increased serum levels of IL-33 in control group ( = .01). Furthermore, serum IL-33 levels were not significantly different between AR patients and healthy controls ( > .05).

Conclusion: Our results suggest that the TT genotype of rs7044343 C > T may act as a protective agent against allergic rhinitis.