BACKGROUND: Nonasthmatic eosinophilic bronchitis is a condition characterized by the presence of eosinophilic airway inflammation in the absence of airflow obstruction or airway hyperresponsiveness. In asthma, the T H 2-type cytokine IL-13 has been implicated in the development of airway inflammation and hyperresponsiveness. Whether the expression of IL-13 is different between these 2 conditions is unknown. OBJECTIVE: We sought to investigate whether IL-13 expression is increased in asthma compared with eosinophilic bronchitis. METHODS: Sputum samples from subjects with mild asthma (n = 30) and eosinophilic bronchitis (n = 15) and normal controls (n = 16) were dialyzed, and IL-13 concentration was measured by ELISA. In a subgroup of these patients, IL-13 protein expression in bronchial biopsies was assessed by immunohistochemistry. RESULTS: The concentration of sputum IL-13 was higher in patients with mild asthma than in normal controls ( P = .03) and in patients with eosinophilic bronchitis ( P = .03). The median (interquartile range) number of IL-13 + cells/mm 2 submucosa was significantly higher in asthma 4 (8) than eosinophilic bronchitis 1.7 (1.9) and normal controls 0.5 (1.1; P = .004). Eighty-three percent of the cells expressing IL-13 in the submucosa were eosinophils, and 8% were mast cells. The median (interquartile range) proportion of eosinophils that expressed IL-13 was higher in the subjects with asthma, 16 (10)%, than those with eosinophilic bronchitis, 7 (3)% ( P = .02). CONCLUSION: The increased expression of IL-13 in asthma compared with eosinophilic bronchitis supports the concept that IL-13 may play a critical role in the pathophysiology of asthma.
BACKGROUND: Nonasthmatic eosinophilic bronchitis is a condition characterized by the presence of eosinophilic airway inflammation in the absence of airflow obstruction or airway hyperresponsiveness. In asthma, the T H 2-type cytokine IL-13 has been implicated in the development of airway inflammation and hyperresponsiveness. Whether the expression of IL-13 is different between these 2 conditions is unknown. OBJECTIVE: We sought to investigate whether IL-13 expression is increased in asthma compared with eosinophilic bronchitis. METHODS: Sputum samples from subjects with mild asthma (n = 30) and eosinophilic bronchitis (n = 15) and normal controls (n = 16) were dialyzed, and IL-13 concentration was measured by ELISA. In a subgroup of these patients, IL-13 protein expression in bronchial biopsies was assessed by immunohistochemistry. RESULTS: The concentration of sputum IL-13 was higher in patients with mild asthma than in normal controls ( P = .03) and in patients with eosinophilic bronchitis ( P = .03). The median (interquartile range) number of IL-13 + cells/mm 2 submucosa was significantly higher in asthma 4 (8) than eosinophilic bronchitis 1.7 (1.9) and normal controls 0.5 (1.1; P = .004). Eighty-three percent of the cells expressing IL-13 in the submucosa were eosinophils, and 8% were mast cells. The median (interquartile range) proportion of eosinophils that expressed IL-13 was higher in the subjects with asthma, 16 (10)%, than those with eosinophilic bronchitis, 7 (3)% ( P = .02). CONCLUSION: The increased expression of IL-13 in asthma compared with eosinophilic bronchitis supports the concept that IL-13 may play a critical role in the pathophysiology of asthma.
Authors: Jinming Zhao; Valerie B O'Donnell; Silvana Balzar; Claudette M St Croix; John B Trudeau; Sally E Wenzel Journal: Proc Natl Acad Sci U S A Date: 2011-08-09 Impact factor: 11.205
Authors: Michael J Holtzman; Jeffrey W Tyner; Edy Y Kim; Mindy S Lo; Anand C Patel; Laurie P Shornick; Eugene Agapov; Yong Zhang Journal: Proc Am Thorac Soc Date: 2005
Authors: Jeffrey W Tyner; Edy Y Kim; Kyotaro Ide; Mark R Pelletier; William T Roswit; Jeffrey D Morton; John T Battaile; Anand C Patel; G Alexander Patterson; Mario Castro; Melanie S Spoor; Yingjian You; Steven L Brody; Michael J Holtzman Journal: J Clin Invest Date: 2006-02 Impact factor: 14.808
Authors: Robert D Gray; Gordon MacGregor; Donald Noble; Margaret Imrie; Maria Dewar; A Christopher Boyd; J Alastair Innes; David J Porteous; Andrew P Greening Journal: Am J Respir Crit Care Med Date: 2008-06-19 Impact factor: 21.405