Saturday, 17 October 2015
Hall D1 Foyer (Floor 3) (Coex Convention Center)
Background: Airway hyperresponsiveness and airway inflammation are the characteristic features in bronchial asthma. Airway hyperresponsiveness is usually measured with direct stimuli such as methacholine or histamine. Adenosine 5'-monophosphate, which acts indirectly via the secondary release of mediators, is another stimulus to measure brochial hyperresponsiveness. The aim of this study was to investigate the relationship among the provocative concentration of methacholine producing a 20% decline in FEV1 (PC20 methacholine), PC20 adenosine and inflammatory markers in newly diagnosed asthmatics and to compare the changes in each after inhaled corticosteroid treatment. Methods: We performed a prospective analysis of data from 20 patients with a diagnosis of persistent bronchial asthma (17-67 years, FEV1>60% predicted). Patients were assigned into two groups according to severity of the disease of either mild (mean FEV1 91.6±4.7%, n=12) or moderate(mean FEV1 62.9±2.9%, n=8). Methacholine and adenosine bronchial provocation test, sputum induction, blood sampling were performed before and after treatment with corticosteroid for 4weeks. Results: The sensitivity of methacholine and adenosine bronchial provocation test in diagnosis of bronchial asthma are 65% and 60%, respectively. Both PC20 methacholine and PC20 adenosine are improved after corticosteroid treatment. Devided into two groups according to severity, in mild group, improvement in PC20 methacholine (p<0.05) after corticosteroid treatment was found but not in PC20 adenosine. In moderate group, improvement in PC20 adenosine (p<0.05) after corticosteroid treatment was found but not in PC20 methacholine. Pre-treatment (pre-) MMP-9 was correlated with PC20 methacholine and PC20 AMP (p<0.05; p<0.05). Strong correlations between pre- IL-8 and pre- MMP-9 (Rho=0.655, p<0.05) and between pre- IL-8 and pre- TIMP-1 (Rho=0.815, p<0.001) was observed. We found that changes in PC20 methacholine and PC20 adenosine after treatment with inhaled corticosteroid are correlated with eosinophil percentage in blood and pre- TIMP-1 in sputum, respectively (Rho=0.488, p<0.05; Rho=0.464, <0.05). All inflammatory markers such as IL-5, IL-8, MMP-9 ,TIMP-1 and ECP decreased after treatment but no significance was found. Conclusions: Our findings show that PC20 adenosine and PC20 methacholine are useful markers to assess the efficacy of antiinflammatory therapy. In moderate persistent asthma, PC20 adenosine may be more valuable to evaluate the efficacy of treatment than PC20 methacholine.