A MCh Test Pre-post Esophageal Acidification in Detecting GER-related Asthma |
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Authors: | Roberto Walter Dal Negro Silvia Tognella Claudio Micheletto Marco Sandri Massimo Guerriero |
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Affiliation: | 1. Ospedale Orlandi, Lung Department, Bussolengo, Italy;2. University of Brescia, Department of Quantitative Methods, Brescia, Italy;3. University of Verona, ESI Dept, Verona, Italy |
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Abstract: | The direct effect of gastro-esophageal reflux (GER) on lung function is still debated. Objective. To investigate the role of esophageal acidification in affecting airway response to MCh in GER-related versus atopic asthmatics and to assess specificity and sensitivity of events. Subjects. A total of 56 never-smoking, mild asthmatics: 27 non-atopic asthmatics and acid GER (GER+ve) and 29 atopic asthmatics without any GER (GER–ve). Methods. Each subject performed an MCh challenge in baseline (MChb), and 30 minutes after an acid drink (125 mL at pH = 2; MChac), one day apart. PD20FEV1 MChb and MChac were compared by estimating the area under the ROC curve (AU-ROC). Results. GER+ve and GER-ve subjects (well matched in baseline) had a different duration of esophageal acid contact (24-hour monitoring; pH-24h AU4), and PD20FEV1 MChac (both p < 0.001). AU-ROC was 86.3% (76% to 97%, 95%CI). Sensitivity and specificity of changes were 82.8% (72.9% to 92.7%, 95%CI) and 85.2% (75.9% to 94.5%, 95%CI), respectively. The difference in MCh threshold that maximized both the sensitivity and specificity level was 100 μ g. Conclusions. The esophageal acidification identified GER-related asthma with a good level of both sensitivity and specificity by enhancing the MCh response only in the presence of acid GER. Data are supporting the effectiveness of this procedure for clinical purposes. |
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Keywords: | gastro-oesophageal reflux bronchial asthma bronchial hyperreactivity lung function GER-related asthma oesophageal acidification |
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