Evaluation of vascular endothelial growth factor A and endostatin levels in induced sputum and relationship to bronchial hyperreactivity in patients with seasonal allergic rhinitis.

Background: Studies about the pathogenesis of bronchial hyperreactivity (BHR) in patients with allergic rhinitis (AR) and its relationship with lower airway remodeling are extremely limited. In this study, bronchial vascular remodeling and its relationship with BHR were evaluated by measurement of vascular endothelial growth factor A (VEGF-A) and endostatin in patients with seasonal AR (SAR).

Methods: The study group consisted of 30 patients with SAR (positive skin test to grass pollens) and 14 healthy controls. Induced sputum and bronchial provocation test (BPT) to methacholine (M) were performed in season. VEGF-A and endostatin levels were measured by ELISA in induced sputum supernatant.

Results: The percentages of eosinophils in induced sputum were significantly increased in BHR+ patients (n = 10) with SAR compared with BHR(-) patients (n = 20) with SAR (p < 0.001). There was no correlation between eosinophils and provocative concentration of M required to produce a 20% decrease in forced expiratory volume in 1 second. The levels of VEGF-A were significantly higher in SAR patients with BHR than in SAR patients without BHR and healthy controls (respectively, p = 0.014 and p = 0.04). The levels of endostatin were significantly lower in SAR patients with BHR than in SAR patients without BHR and healthy controls (respectively, p = 0.020 and p = 0.014). The ratio of VEGF-A/endostatin was significantly higher in SAR patients with BHR than in SAR patients without BHR and healthy controls (respectively, p = 0.009 and p = 0.019).

Conclusion: In this first study comparing the VEGF-A and endostatin levels of patients with SAR in sputum supernatant, the presence of BHR was shown to be associated with the vascular component of remodeling "angiogenesis."