Polymorphisms in the interleukin 4, interleukin 4 receptor and interleukin 13 genes and allergic phenotype: A case control study

Purpose: Interleukin 4 (IL4), interleukin 4 receptor (IL4R) and interleukin 13 (IL13) play a key role in the pathogenesis of allergy and asthma development. IL4 and IL13 strongly influence bronchial hyperreactivity in response to allergen, airway remodeling, airway inflammation and airway smooth muscle proliferation. Both IL4 and IL13 exert biologic effect via interleukin 4 receptor. The aim of this study was to evaluate the impact of the polymorphisms within interleukin 4 (rs2243250, rs2227284), interleukin 4 receptor α chain (rs1805010, rs1805011) and interleukin 13 (rs20541) genes on the incidence of allergic phenotype in Polish pediatric population.

Material/methods: We compared 177 asthmatic pediatric patients with 194 healthy children. Five polymorphisms within IL4, IL13 and IL4Rα genes were analyzed. Genotypes of four polymorphisms (rs2243250, rs2227284, rs1805011, rs20541) were assigned by TaqMan SNP Genotyping Assays (Applied Biosystems), whereas rs18050100 polymorphism was established using PCR-RFLP method.

Results: We observed an association of rs1805011 polymorphism of IL4Rα gene with allergy (p=0.021), mild asthma (p=0.00005) and atopic dermatitis (p=0.0056). Significant correlation was found between rs20541 in IL-13 gene and the positive skin prick test results (p=0.029), along with rs2243250 polymorphism with clinical atopy (p=0.033) and rs2227284 with total IgE levels (p=0.00047). No associations were found for rs1805010.

Conclusions: Our results indicate that rs1805011 polymorphism of IL4Rα gene seems to influence allergy risk, especially mild asthma and atopic dermatitis predisposition in Polish children. Subgroup analysis of three other SNPs revealed possible influence on allergy development.