Bronchial asthma and airway remodeling markers

Abstract

Asthma is an inflammatory disease with extracellular matrix remodeling and collagen deposition. Vascular alterations have been suggested to contribute to airway hyper responsiveness. Vascular endothelial growth factors and metalloproteinases are mediators of airway inflammation and remodeling in asthma. There are few data regarding the potential effects of anti-asthma treatment on indices of air way remodeling. ObjectiveThis study investigates the role of VEGF, MMP-9 in the pathogenesis of asthma and their role as index of remodeling, markers of inflammation in symptomatic bronchial asthma on low dose ICS. Also we evaluate the role of adding long acting B2 agonist for 6weeks in airway remodeling for the symptomatic asthmatic patients on low dose ICS. MethodsVEGF and MMP-9 were measured in sputum of healthy control, and bronchial asthma patients before and after the addition of long acting B2 agonists. Also we evaluated whether VEGF correlated with MMP-9 in symptomatic bronchial asthma receiving low or moderate dose of ICS. ResultsLevels of VEGF and MMP-9 are significantly higher in sputum of bronchial asthma than in healthy controls. The mean level of VEGF, MMP-9 in sputum of bronchial asthma patients on low to moderate dose of ICS was 2500pg/ml±750, 33.3ng/ml±16.7. After 6weeks of treatment with long acting B2 agonists there was a reduction in the mean levels of both VEGF, MMP-9 1750pg/ml±250, 27.4ng/ml±l3. Also there was a significant correlation between the levels of VEGF and MMP-9 in healthy subjects and patients with bronchial asthma. There was a significant correlation between both VEGF MMP-9 and the sputum eosinophils and neutrophil in patients with bronchial asthma before adding long acting B2 agonists. ConclusionSymptomatic patients with bronchial asthma on a low dose ICS have elevated levels of VEGF, MMP-9. There was an interrelationship between VEGF and MMP-9, this finding suggests that VEGF signaling regulates MMP-9 expression, and plays a critical role in the maintenance of asthma. VEGF, MMP-9 could be considered as important markers of airway remodeling in asthma. The addition of regular long acting B2 agonist to low or moderate dose ICS in symptomatic bronchial asthma patients had a beneficial effect on the air way remodeling markers in a way that they may potentate the anti-inflammatory effects of ICS on inflammatory cells.