Correlation between the airway inflammations and levels of stromal cell-derived factor 1 in induced sputum of asthmatic patients

Abstract

To evaluate concentrations of stromal cell-derived factor 1 (SDF-1) and IL-17 in induced sputum supernatants from asthmatic patients before and after treatment with glucocorticosteroids. Induced sputum was collected from 30 healthy controls and 99 patients with chronic persistent asthma from 2009-2010. Sputum samples were obtained before and after 4 week treatment with inhaled glucocorticosteroids. The sputum concentrations of SDF-1 and IL-17 were measured by ELISA. The FEV(1)% and the asthma control score of patients with severe asthma were decreased as compared with patients with moderate persistent and mild persistent asthma (F = 457.448 and 79.271, all P < 0.01). The concentrations of SDF-1, IL-17 and the percentage of eosinophils were increased in asthma group compared with control subjects (all P < 0.01), but the percentage of sputum neutrophils was lower than that in the healthy controls (P < 0.01). The percentage of sputum neutrophils and eosinophils and the level of SDF-1 and IL-17 in patients with severe persistent asthma were significantly higher than those in patients with mild persistent asthma (all P < 0.05). The percentage of sputum neutrophils and eosinophils were negatively correlated with FEV(1)% (r = -0.409 and -0.316, all P < 0.05). The levels of IL-17 and SDF-1 were positively correlated with the percentage of sputum neutrophils and eosinophils (all P < 0.01). The levels of IL-17 were positively correlated with the levels of SDF-1 (r = 0.872, P < 0.01). After glucocorticosteroid therapy, the percentage of eosinophils and neutrophils, the levels of IL-17 and SDF-1 decreased significantly in all patients (all P < 0.01), while the percentage of sputum neutrophils and the levels of IL-17 and SDF-1 in uncontrolled patients increased significantly compared with the controlled and partly controlled groups (all P < 0.05). SDF-1 and IL-17 may contribute to airway inflammation in asthma by chemotactic activity towards neutrophils. The concentration of SDF-1 may be used to evaluate the inflammation and the therapeutic effects.