The Study of IL-10 and IL-17A Genes Expression in Patients with Different Stages of Asthma: a Case-Control Study

Abstract

Background: Asthma is considered as a complex disorder in which genetics and environment play crucial role in its susceptibility. In addition to the huge financial costs that significantly reduce the quality of life of the patients and their families, it causes high prevalence of lung diseases. Finding contributing new genetic factors involved in early diagnosis or progression of asthma can provide novel approaches for treatment or managing of asthma. In the present study, the potential role of two key cytokines of IL-10 and IL-17A was investigated in asthma pathogenesis.

Materials and methods: Using real-time PCR technique, we analyzed the expression levels of target genes in two groups of mild and severe asthma patient in comparison with healthy individuals.

Results: In comparison with control population, obtained data showed 4 and 7-fold down-regulation of IL-17A in the group of mild and severe asthma, respectively. Down-regulation of IL-17A showed a significant correlation with progression of asthma severity. While IL-10 showed up to 10-fold down-regulation in the group of severe asthma, its expression level was not correlated with severity of asthma.

Conclusion: Obtained data revealed that deregulation IL-10 and IL-17A have potential to play crucial role in pathogenesis and prognosis of asthma. Observed down-regulation of these cytokines in blood cells suggests their usefulness as a marker in diagnosis of asthmatic types in patients.

Keywords: Asthma; Cytokine expression; IL-10; IL-17A; PBMC, qPCR.

Figure 1.

Comparison of normalized and fold change expression of IL-17Aand IL10 in control, mild and severe asthma. The normalized expression of IL-17A is statistically different between severe asthma and control group (P value = 0.006) (A). While IL-17A is down-regulated in both mild and severe asthma samples, IL-10 down-regulation is limited to severe asthma (B). The fold change analysis of gene expression in IL-17A showed a significant decrease of 3.8 and 8.2-times in mild and severe asthma in comparison to the control, respectively (C). This analysis for IL-10 gene expression showed a diverse pattern in mild (about 2-times) increasing and in severe asthma (about 10 –times) decreasing in comparison to the control group (D).

Figure 2.

Correlation of IL-17Aand IL-10 expression level in normal (A), mild (B) and severe (C) cases. Patients with mild asthma showed no correlation between these genes, while there is a statistical significance correlation between expression of two target genes of IL-17Aand IL-10 in severe asthma patients.

Figure 3.

Relationship between the expression level of IL-17Aand IL-10 genes and ages of individuals with healthy (A and D), mild asthma (B and E) and severe asthma (C and F) situations. As shown, the scattering of expression levels (denoted as non-fill points) is not statistically significant.