Vascular remodeling is a feature of asthma and nonasthmatic eosinophilic bronchitis

RationaleIncreased vascularity and expression of vascular endothelial growth factor (VEGF) are recognized features of the asthmatic airway. The association of vascular remodeling with airway hyperresponsiveness (AHR) is unclear.ObjectiveTo assess vascular remodeling and sputum VEGF concentration in subjects with asthma, subjects with nonasthmatic eosinophilic bronchitis (EB), and healthy controls.MethodsIn cohort 1, 19 patients with asthma (Global Initiative for Asthma [GINA] 1-2, n = 9; GINA 3-5, n = 10), 10 patients with EB, and 11 healthy matched controls were recruited. Expression of the endothelial marker EN4 was assessed in bronchial biopsy samples. Vessels were counted using the validated mean Chalkley count by a blind observer. For cohort 2, a second independent cohort of 31 patients with asthma (GINA 1-2, n = 11; GINA 3-5, n = 20), 14 patients with EB, and 15 matched controls was recruited. Induced sputum supernatant VEGF was measured by ELISA.ResultsThe mean chalkley count was significantly greater in GINA 3-5 asthma (5.2 [0.4]) and EB (4.8 [0.3]) compared with controls (3.5 [0.5]) and demonstrated a significant inverse correlation with the postbronchodilator FEV1% predicted in patients with asthma (R2 = 0.28; P = .02). Sputum VEGF concentration was also increased in GINA 3-5 asthma (2365 [1361-4110] pg/g) and EB (4699 [2818-7834] pg/g) compared with controls (1094 [676-1774] pg/g) and was inversely related to postbronchodilator FEV1% predicted in asthma (R2 = 0.2; P = .01).ConclusionVascular remodeling is a feature of asthma, and EB and is inversely associated with the postbronchodilator FEV1 in asthma, suggesting that vascular remodeling is associated with airflow obstruction but not AHR.Clinical implicationsVascular remodeling is dissociated from AHR in asthma and associated with airflow limitation.