STUDY OBJECTIVES: Experimental studies on asthma have indicated that interleukin (IL)-13 induces airway hyperreactivity (AHR). However, it remains unproven that IL-13 is responsible for AHR in asthmatic patients. Eosinophilic bronchitis (EB) shows normal airway responsiveness despite eosinophilic airway inflammation of severity similar to that of asthma. This study evaluated the role of IL-13 in asthma by comparing the sputum IL-5 and IL-13 levels in both groups. METHODS: Comparisons between asthma and EB would clarify the role of IL-13 in AHR. IL-5 and IL-13 were assayed in the sputum and culture supernatants of peripheral blood mononuclear cells (PBMCs) from 22 asthmatic patients, 12 EB patients, and 11 healthy control subjects. RESULTS: IL-13 levels were higher in the asthmatic patients than in the EB patients or healthy control subjects (p = 0.001). IL-5 levels were similar in the asthmatic patients and EB patients, who had significantly higher levels than those of healthy control subjects. Sputum IL-13, but not IL-5, is inversely correlated with the provocative concentration of a substance causing a 20% fall in FEV1 for methacholine in asthmatic patients (r = -0.502; p = 0.017). IL-13 production by PBMCs was significantly higher in asthmatic patients than in EB patients (p = 0.015), but the levels between EB patients and healthy control subjects was comparable. CONCLUSION: The results of the present study indicate that IL-13 is related to AHR in asthmatic patients.
STUDY OBJECTIVES: Experimental studies on asthma have indicated that interleukin (IL)-13 induces airway hyperreactivity (AHR). However, it remains unproven that IL-13 is responsible for AHR in asthmatic patients. Eosinophilic bronchitis (EB) shows normal airway responsiveness despite eosinophilic airway inflammation of severity similar to that of asthma. This study evaluated the role of IL-13 in asthma by comparing the sputum IL-5 and IL-13 levels in both groups. METHODS: Comparisons between asthma and EB would clarify the role of IL-13 in AHR. IL-5 and IL-13 were assayed in the sputum and culture supernatants of peripheral blood mononuclear cells (PBMCs) from 22 asthmatic patients, 12 EB patients, and 11 healthy control subjects. RESULTS:IL-13 levels were higher in the asthmatic patients than in the EB patients or healthy control subjects (p = 0.001). IL-5 levels were similar in the asthmatic patients and EB patients, who had significantly higher levels than those of healthy control subjects. Sputum IL-13, but not IL-5, is inversely correlated with the provocative concentration of a substance causing a 20% fall in FEV1 for methacholine in asthmatic patients (r = -0.502; p = 0.017). IL-13 production by PBMCs was significantly higher in asthmatic patients than in EB patients (p = 0.015), but the levels between EB patients and healthy control subjects was comparable. CONCLUSION: The results of the present study indicate that IL-13 is related to AHR in asthmatic patients.
Authors: Annette T Hastie; Wendy C Moore; Deborah A Meyers; Penny L Vestal; Huashi Li; Stephen P Peters; Eugene R Bleecker Journal: J Allergy Clin Immunol Date: 2010-04-15 Impact factor: 10.793
Authors: Barry Moynihan; Barbara Tolloczko; Marie-Claire Michoud; Meiyo Tamaoka; Pasquale Ferraro; James G Martin Journal: Am J Physiol Lung Cell Mol Physiol Date: 2008-04-25 Impact factor: 5.464
Authors: Salman Siddiqui; Glenn Cruse; Susan McKenna; William Monteiro; Vijay Mistry; Andrew Wardlaw; Christopher Brightling Journal: BMC Pulm Med Date: 2009-07-14 Impact factor: 3.317