Assessment Airway Remodeling In Asthma By Use Of High-resolution CT, Biological Makers And Pulmonary Function

Objective:To explore the roles of biomarkers of MMP-9,TIMP-1 and TGF-β1 in induced sputum,high-resolution CT and pulmonary function in assessing airway remodeling in asthma.Method:Forty-eight patients with asthma were chosen in the first hospital of Shanxi medical university from June to December 2008. According whether airflow obstruction was reversible or not being used p2-receptor agonists,they were divided into two groups:irreversible airflow obstruction group and reversible airflow obstruction one,and 24 patients each group,and control group included 10 persons.The sputum was induced with Saline,and the MMP-9,TIMP-1 and TGF-β1 level of the sputum were determined with ELISA.All selected persons over the same period did pulmonary function and HRCT tests.The wall thickness two-fold to airway diameter ratio(2T/D) and the percentage of airway wall area to total airway cross sectional area(WA%) were calculated on high resolution computed tomography.Result:(1) The levels of MMP-9, TIMP-1 and TGF-β1 in asthma group were higher than those in the controlled group (P＜0.05) respectively;and those in the irreversible airflow obstruction group were higher than ones in the reversible airflow obstruction group (P＜0.05) respectively.The MMP-9/TIMP-1 ratio in asthma group was lower than in control group (P＜0.05);and the irreversible airflow obstruction group was lower than the reversible airflow obstruction group,(P＜0.05).(2) 2T/D and WA%were higher in asthma group than in control group (P＜0.05) respectively;and the irreversible airflow obstruction group was higher than the reversible airflow obstruction group,(P＜0.05).(3) The MMP-9 level of induced sputum was positively correlated with 2T/D and WA%(r=0.755,0.751,P＜0.05);The TIMP-1 level was positively correlated with 2T/D and WA%(r=0.639,0.630,P＜0.05);The TGF-β1 level was also positively correlated with 2T/D and WA%(r=0.872,0.868,P＜0.05).(4) MMP-9, TIMP-1, TGF-β1,2T/D and WA%were negatively correlated with FEV1%(r=-0.496,-0.468,-0.607,-0.599,-0.586,P＜0.05);those were negatively correlated with FVC%(r=0.312,-0.359,-0.399,-0.407,-0.388,P＜0.05);those were also negatively correlated with FEF25-75%(r=-0.558,-0.477,-0.649,-0.645,-0.651,P＜0.05)Conclusion:(1) The airway remodeling can be assessed by HRCT.(2) MMP-9, TIMP-1 and TGF-β1 in induced sputum could be as biomarkers as airway remodeling in asthma. (3) MMP-9,TIMP-1,TGF-β1 in induced sputum and HRCT could find airway remodeling earlier,which may be guiding clinical treatment and monitoring therapeutic effect. (4) It was a safe and effective way that airway secretions were obtained through the induced sputum.