Association between the IL-7Rα gene polymorphisms of rs6897932 and rs987106 with atopic diseases: A case-control design

Abstract

Background Atopy is used to describe the genetic tendency to IgE-mediated responses. Many factors contribute to predisposing individuals to atopy, including cytokines. IL-7 is a cytokine that mediates hypersensitivity responses and proliferation of T cells and has a polymorphic gene for its receptor (CD127). These different alleles may affect the signaling cascade or alter the production of inflammatory cytokines, which may exacerbate atopic conditions, including asthma and allergy. Objective Primary objective of our study aimed to explore the linkage between IL-7Rα gene polymorphism at the SNP of rs6897932 and the risk of atopic diseases. Evaluating the association of IL-7Rα SNP of rs987106 and also serum levels of IL-7 with the risk of atopy are among the secondary objectives. Methods To seek possible relations of SNPs rs6897932 and rs987106 with the risk of atopy, we recruited 101 atopic patients and 201 sex-age matched healthy controls from Iranian ethnicity and used the data for evaluation. Results Statistical analysis revealed that the T allele variant of IL-7Rα gene at the SNP of rs6897932 is more prevalent among the atopic patients (53.5%) than in the controls (26.9%) and have a considerable association with the disease (p < 0.0001, OR: 3.13 (95% CI- 1.90 to 5.16)). Also, the higher frequency of T allele variant of rs987106 in atopic patients (64.4%) versus control (31.3%) was associated with around a 4-fold increase in the risk of atopy (p < 0.0001, OR: 3.95 (95% CI- 2.39 to 6.55)). However, there was no significant association between IL-7 serum levels and atopic disorders (p > 0.05). Conclusion Our study in the Iranian population may support that T allele variants of rs6897932 and rs987106 are risk factors for atopy. However, serum levels of IL-7 were not significantly associated with a heightened risk of atopy.