Article ID Journal Published Year Pages File Type
3341215 Allergology International 2007 7 Pages PDF
Abstract

ABSTRACTBackgroundExhaled nitric oxide (eNO) is a useful marker of eosinophilic airway inflammation in asthma patients. There is no study to show the relationship between the eNO measured by using an off-line method and the degree of reversibility of airflow limitation in Japanese asthma patients. We sought to investigate the relationship between the eNO level measured by using an off-line method and the degree of reversibility of bronchial constriction in Japanese asthma patients.MethodsThe study population comprised 97 asthma patients in our outpatient clinic with some patients in both groups who received inhaled corticosteroid treatment. We measured eNO levels, forced expiratory volume in one second (FEV1) before and after treatment, reversible airway obstruction (ΔFEV1) after inhalation of bronchodilator, and other parameters.ResultseNO was significantly correlated with peripheral blood eosinophil counts in asthma patients (in steroid-naïve asthma patients, r = 0.544, p < 0.0001; in asthma patients treated with inhaled corticosteroid, r = 0.463, p = 0.026), and subjects with severe eosinophilia in sputum showed high levels of eNO (mild eosino- philia versus severe, p = 0.0152). Among patients with obstructive impairment, eNO levels were correlated with ΔFEV1 regardless of whether patients received (r = 0.527, p = 0.0435) or did not receive (r = 0.64, p = 0.0056) inhaled corticosteroid. In subjects with normal pulmonary function, there was no significant relationship between eNO and AFEV1 with or without inhaled corticosteroid.ConclusionsIn patients with obstructive impairment, eNO reflects the degree of reversible airflow limitation. In subjects with normal pulmonary function, eNO may facilitate the diagnosis and management of asthma, rather than indicate reversible bronchial obstruction. eNO measurement by off-line methods is applicable as a potential tool for the diagnosis of asthma and management of asthma patients.

Related Topics
Health Sciences Medicine and Dentistry Immunology, Allergology and Rheumatology