Assessment of the Effects of IL9, IL9R, IL17A, and IL17F Gene Polymorphisms on Women with Allergic Rhinitis in Shahrekord, Iran.

Abstract

Background: The genes encoding IL9, IL9R, IL17A, and IL17F have recently been implicated in the genetic basis of rhinitis and allergy.

Aim: The purpose of this study was to assess the association of the single nucleotide polymorphisms (SNPs) of IL9, IL9R, IL17A, and IL17F and potential interaction of these genes with the determination of IgE levels in women with allergic rhinitis (AR) in Shahrekord, Iran.

Subjects and methods: In a case-control study, SNPs from the IL9, IL9R, IL17A, and IL17F were genotyped in 394 random samples including 195 AR patients and 199 normal controls. Enzyme-linked immunosorbent assay was performed for the determination of serum total IgE levels. The Student's t-test was used to compare the differences. The Chi-square test was performed to compare proportions of cases with different clinical features among cases with different genotypes. The genotype and allele frequencies were obtained by direct counting. Hardy-Weinberg equilibrium was tested between cases and controls separately. The relative risk associated with rare alleles was estimated as an odds ratio with 95% confidence interval. P ≤ 0.05 was considered statistically significant.

Results: The rs731476 SNP in the IL9R was significantly associated with the AR phenotype in women. No association was found between any of the other SNPs in IL9, IL17A, and IL17F genes and AR. In the gene-gene interaction analysis, we found that IL9R/IL9 genotype rs731476 T-/rs2069885 G conferred a higher risk for AR phenotype development. We also did not find a significant association in terms of IgE levels between cases and controls.

Conclusion: Our result suggests that the rs731476 SNP located in the IL9R is associated with an increased susceptibility to AR in females. In a subsequent gene-gene interaction analysis, the rs731476 T-/rs2069885 G-genotype combination (IL9R/IL9) has significantly been associated with the development of the AR phenotype.