Background

The purpose of this research is to examine whether or not there is a connection between polymorphisms in the IL-5 and IL-9 genes and the prevalence of allergic asthma in Iraqi patients.

Objective

To investigate the variants in the genes rs2069812T/C (IL-5) and rs1859430 C/T (IL-9) and their association with the likelihood of developing allergic asthma.

Methods

Two hundred forty, one hundred twenty without asthma and one hundred twentywith the condition, made up the healthy subjects. We determined the levels of IL-5 and IL-9 using the enzyme-linked immunosorbent assay (ELISA) after separating sera from peripheral blood. Additionally, the allele-specific PCR method was used to identify the polymorphism distribution of rs2069812 (IL-5) and rs1859430 (IL-9).

Results

Study participants with allergic asthma had significantly higher levels of interleukin (IL)-9 and interleukin (IL)-5 than those in the healthy subjects: 2 and 2.39 ± 0.18 pg/ml, compared to 1.004 ± 0.04 pg/ml and 2.21 ± 0.16 pg/ml, respectively, with a significance level of P < 0.05. In terms of age, gender, and place of residence, there was no statistically significant difference between the ill group and the healthy control group. The patients’ group had 66 cases of the heterozygous genotype TG compared to 58 cases in the control group. Thus, the TG genotype was associated with an increased risk of allergic asthma illness (etiologic fraction: 0.2963) and an odds ratio of 2.4074 (95% CI: 1.2462–4.6505). The patients’ group also had a higher frequency of the homozygous genotype GG (65 cases vs. 54 cases in the control group). The odds ratio for allergic asthma illness was 1.0578 (95% CI: 0.6386–1.7522), and the etiologic fraction was 0.0299, indicating that genotype GG was a risk factor.

Conclusions

These findings provide more evidence that interleukin-5 and interleukin-9 play critical roles in allergic asthma, particularly in eosinophilic inflammation. Consequently, it is important to target them in order to reduce asthma allergy and improve asthma treatment. It is clear that IL-5 and IL-9 levels directly influence allergic asthma in patients compared with healthy individuals.