Association of airway pentosidine levels with bronchodilator response mediated by salbutamol administration in asthmatic patients

BackgroundRecently, increased levels of pentosidine, an intermolecular cross-linking type of advanced glycation end products, are observed in the airways of asthmatic patients. This study was designed to determine whether differences in bronchodilator response among individuals with asthma are attributable to pentosidine levels in their airways.MethodsFifty-six asthmatic patients (21 with airway obstruction, 35 without airway obstruction) and 10 normal controls were included in this study. For asthmatic patients, we evaluated the spontaneous reversibility of airway obstruction or the reversibility that can be obtained after methacholine provocation. And we also measured pentosidine levels and percentage of sputum eosinophils in induced sputum, and exhaled nitric oxide (NO) levels.ResultsThe pentosidine levels did not significantly differ between the two asthmatic subgroups with and without airway obstruction. In asthmatic patients without airway obstruction, airway hyperresponsiveness to methacholine (PC20 methacholine) was significantly correlated with sputum eosinophils and exhaled NO levels. In contrast, PC20 methacholine was not significantly correlated with pentosidine levels. In asthmatic patients with or without airway obstruction, bronchodilator response was not significantly correlated with sputum eosinophils and exhaled NO levels. However, bronchodilator response was closely correlated with pentosidine levels (asthmatics without airway obstruction: r = −0.54, p = 0.002; asthmatics with airway obstruction: r = −0.48, p = 0.03).ConclusionsOur results showed that pentosidine might be a potential biomarker reflecting the reduced bronchodilator response in asthma. This study will provide new insights into the mechanisms underlying persistent airway obstruction.