Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài:" Exhaled nitric oxide and clinical phenotypes of childhood asthma. | Mahut et al. Respiratory Research 2011 12 65 http content 12 1 65 RESPIRATORY RESEARCH RESEARCH Open Access Exhaled nitric oxide and clinical phenotypes of childhood asthma Bruno Mahut1 2 3 Séverine Peyrard5 and Christophe Delclaux2 3 4 5 Abstract Whether exhaled NO helps to identify a specific phenotype of asthmatic patients remains debated. Our aims were to evaluate whether exhaled NO is independently associated 1 with underlying pathophysiological characteristics of asthma such as airway tone bronchodilator response and airway inflammation inhaled corticosteroid ICS -dependant inflammation and 2 with clinical phenotypes of asthma. We performed multivariate exhaled NO as dependent variable and k-means cluster analyses in a population of 169 asthmatic children age SD years recruited in a monocenter cohort that was characterized in a cross-sectional design using 28 parameters describing potentially different asthma domains atopy environment tobacco control exacerbations treatment inhaled corticosteroid and long-acting bronchodilator agonist and lung function airway architecture and tone . Two subject-related characteristics height and atopy and two disease-related characteristics bronchodilator response and ICS dose 200 pg d explained 36 of exhaled NO variance. Nine domains were isolated using principal component analysis. Four clusters were further identified cluster 1 47 boys unexposed to tobacco with well-controlled asthma cluster 2 26 girls unexposed to tobacco with well-controlled asthma cluster 3 6 girls or boys unexposed to tobacco with uncontrolled asthma associated with increased airway tone and cluster 4 21 girls or boys exposed to parental smoking with small airway to lung size ratio and uncontrolled asthma. was not different in these four clusters. In conclusion is independently linked to two pathophysiological characteristics of asthma ICS-dependant inflammation and bronchomotor tone but does
