Evaluation of airway inflammation by quantitative Th1/Th2 cytokine mRNA measurement in sputum of asthma patients. Issue 3 (31st January 2006)

• Record Type: Journal Article
• Authors: Truyen, E; Coteur, L; Dilissen, E; Overbergh, L; Dupont, L J; Ceuppens, J L; Bullens, D M A
• Is Part Of: Thorax. Volume 61:Issue 3(2006)
• Page Start: 202
• Page End: 208
• Publication Date: 2006-01-31
• Subjects: ASS, asthma symptom score -- eNO, exhaled nitric oxide -- FEV1, forced expiratory volume in 1 second -- ICS, inhaled corticosteroids -- IFN-γ, interferon γ -- IL, interleukin -- mAb, monoclonal antibody -- mRNA, messenger RNA -- PC20, histamine concentration provoking a 20% decrease in FEV1 -- Th, T helper; induced sputum -- Th1/Th2 cytokines -- asthma -- severity; Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thx.2005.052399
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : Background: Asthma is a chronic inflammatory disorder of the airways driven by T cell activation. Th2 cells and their cytokines are thought to play a role in the pathophysiology of allergic as well as non-allergic asthma. Methods: Airway cells were obtained by sputum induction from 15 healthy and 39 asthmatic individuals and the airway T cell cytokine profiles (interleukin (IL)-4, IL-5, IL-13, IL-10 and interferon (IFN)-γ) at the mRNA level were studied by real time RT-PCR. Results: Asthma patients had increased expression of IL-5 (p = 0.001) and IL-13 (p = 0.03) mRNA in sputum compared with non-asthmatic controls. IL-4 mRNA and IFN-γ mRNA were detectable in the sputum of 44% and 21% of patients, respectively, but not in controls. Sputum IL-10 mRNA levels did not differ significantly between patients and controls. Sputum mRNA expression levels of IL-4, IL-5, and IL-13 were significantly correlated with the percentage of eosinophils and were higher in subjects with allergic asthma than in those with non-allergic asthma (p = 0.03, p = 0.02 and p = 0.0002, respectively); they did not differ between mild asthmatic subjects and those with moderate to severe asthma. In contrast, IFN-γ mRNA expression was higher in non-allergic than in allergic patients (p = 0.04) and higher in patients with moderate to severe asthma than in those with mild asthma (p<0.01). Sputum IL-5 mRNA levels (but not the other cytokine mRNA levels) were also correlated with exhaled nitric oxide (eNO) and with bronchial hyperreactivity expressed as the histamine concentration resulting in a 20% decrease in forced expiratory volume in 1 second. Conclusion: Real time RT-PCR analysis of mRNA in induced sputum confirms a predominance of Th2 cytokines in both allergic and non-allergic asthma. IL-5 levels reflect eosinophil infiltration as well as eNO levels and hyperreactivity, and levels of the Th1 cytokine IFN-γ indicate asthma severity. The technique is a promising tool for use in further studies of asthma severity and disease activity.