VDR gene expression in asthmatic children patients in relation to vitamin D status and supplementation

Abstract

Background Asthma is a common and heterogeneous respiratory disease characterized by airway obstruction and chronic inflammation. Innate and adaptive immune system plays an important role in its pathogenesis. Vitamin D has regulatory effects on the immune system via gene expression. Its functions are mediated by the transcription factor vitamin D receptor (VDR). Our aim was to analyze VDR gene expression and vitamin D status in asthmatic children, and to evaluate the effect of vitamin D supplementation on asthma severity as well as VDR mRNA level.

Methods VDR mRNA expression was measured by real-time PCR in 50 patients and 20 healthy controls. Serum vitamin D, asthma exacerbations and spirometry level were evaluated. Patients with deficiency were supplemented for two months and the level of serum Vitamin D and VDR expression level were remeasured.

Results Results showed that Vitamin D level was low in all patients. VDR mRNA level significantly upregulated in patients than the control group (P = 0.01) and significantly down regulated in response to 2 months of Vit D supplementation (P < 0.01). Significant improvement of the level of asthma control and spirometry readings accompanied the elevation of vitamin D level.

Conclusion VDR expression level associated with bronchial asthma and may serve as a predictor. The present study provides some molecular evidences about vitamin D effectiveness in bronchial asthma treatment.