VEGF and activated eosinophils in children with asthma and eosinophilic bronchitis

Abstract

Purpose: Vascular endothelial growth factor (VEGF) is an important mediator of airway inflammation and remodeling in asthma. We aimed to explore whether VEGF is expressed at elevated levels in asthmatic airways or eosinophilic bronchitis (EB) and associated with eosinophilic inflammation, pulmonary function, and airway hyperresponsiveness (AHR) in children. Methods: One hundred seventeen asthmatic children, 77 children with EB, and 84 healthy children were enrolled. Sputum supernatants were collected and VEGF and eosinophil cationic protein (ECP) levels were measured. Results: Asthmatic children had significantly higher levels of VEGF in induced sputum [89.04 (29.95-178.09) pg/mL] compared to children with EB [25.30 (11.02-80.23) pg/mL] and healthy children [37.37 (16.56-71.30) pg/mL; P=0.0003]. VEGF in sputum positively correlated with sputum ECP (r=0.524; P<0.0001). Negative significant correlations were found between sputum VEGF and FEV1, (r=-0.252; P=0.001) or post-bronchodilator FEV1 (r=-0.181; P=0.038) whereas nonsignificant correlations were found between sputum VEGF and sputum eosinophils. Conclusion: Our findings suggest that VEGF is associated with activated eosinophils in the asthmatic airway, but not EB. Sputum VEGF could be a supportive marker that represents activation of airway eosinophils and persistent airflow limitation in asthmatic children.