Determination of mRNA Expression and Serum Levels for IL-4 and IL-13 in Asmathic Patients

Abstract

INTORDUCTION: Immune and inflammatory responses that mediated by cytokines play an important relo in the pathophisiology of asthma. These responses are associated with over expression of Th2 cytokines such as IL-4 and IL13. These two sytokines use shared receptors for signaling that lead to identical immunological effects and the requlation of the Th1/Th2 balance. The aim of this study was to determine whether patients during asthmatic attack had over-expression of IL-4 and IL-13 genes. MATERIALS AND METHODS: Using RT-PCR, we examined IL4 and IL-13 mRNA gene expression in twenty asthmatic cases and twenty healty individual who had not symptoms or history of asthma and other allergic disease. Extracted mRNA form activated PBMCs of one healthy control with PHA is used as positive control. Total serum IgE and IL-4 level were determined by ELISA Method. RESULTS: IL-13 mRNA expression in 70% of patients during asthmatic attack increased in resoect to control (p-value=0.01) but no correlation exist between IL-13 mRNA and total serum IgE (p-value=0.0708). Thirty percent of patients had IL-4 gene expression by RT-PCR(P=0.01), but none of controls had IL-4 gene expression. Mean serum IgE level in patients and in normal indiciduals were 84.9 IU/ml and 62.2 IU/ml (p=0.01) respectively. Thirty percent of patients had IgE level greater than 100 IU.ml (p=0.01). There was correalation between serum IgE and IL-4 in 73% of cases. CONCLUSION AND DISCUSSION: The results showed that, there is some correlation betweem IL-4 gene expression and serum IL-4. All results indicate that serum IgE and IL-4 concentratin is considerably higher in asthmatics than non-asthmatic controls. There is a correlation between IL-4 gene expression and IL-4 glycoprotien in serum as a gene product. IL-13 mRNA expression in 70% of patients during asthmatic attack increased in respect to cintrols. Eventually, this study provides additional evidence that Th2 cytokines (IL-13, IL-4) gene expression play a key role in the imbalance of Th1/Th2 in asthmatic patients; but the role of IL-13 in more significant. KEY WORDS: Asthma, IL-4, IL-13, RT-PCR.