An investigation of airway acidification in asthma using induced sputum - A study of feasibility and correlation
An investigation of airway acidification in asthma using induced sputum - A study of feasibility and correlation
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DOI：
10.1164/rccm.200607-940oc
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发表时间：
2007-05-01
影响因子：
24.7
通讯作者：
Confalonieri, Marco
中科院分区：
文献类型：
--
作者：
Kodric, Metka;Shah, Ajay N.;Confalonieri, Marco
原理：气道酸化似乎与哮喘的病理生理有关，但其评估可能很困难。目的：本研究的目的是评价诱导痰法测定气道酸化的可行性、有效性及其在哮喘中的临床意义。方法：对57例门诊哮喘患者进行诱导痰标本采集。在14名哮喘患者的独立人群中测量48小时后的样本间重复性。使用pH计测量pH。通过哮喘控制问卷确定哮喘控制情况。测量和主要结果：pH值测量在所有样本中均可行，并且在样本内（组内相关系数[ICC]，0.96）和样本间（ICC，0.621）均可重复。平均pH值在健康受试者和哮喘患者之间存在显著差异，包括那些控制哮喘的患者。（平均pH：健康受试者为7.54，哮喘控制受试者为7.28; p = 0.0105）和疾病未控制受试者（平均pH值：健康受试者为7.54，疾病未控制受试者为7.06;哮喘稳定期和哮喘控制不佳的患者之间（分别为7.28 vs. 7.06; p = 0.0134）。用受试者工作特征曲线和诱导痰pH值下限评估该方法的有效性（临界值为7.3;敏感性为72.1%;特异性为100%）。结论：哮喘患者的pH值低于健康受试者。哮喘控制不佳的患者诱导痰pH值似乎最低，与GINA（全球哮喘防治倡议）严重程度无关。结论：诱导痰是一种可行的、可重复的、无创性的气道pH测定方法，诱导痰pH值与嗜酸性粒细胞反映哮喘的不同方面，并与不同的病理生理因素有关。
Rationale: Acidification of the airways seems to be involved in asthma pathophysiology, but its assessment might be difficult. Objectives: The aim of our study is to assess the feasibility and validity of airway acidification measurement by induced sputum and its clinical significance in asthma. Methods: Induced-sputum samples were obtained in 57 outpatients with asthma. The between-sample repeatability after 48 hours was measured in an independent population of 14 patients with asthma. pH was measured using a pH meter. The control of asthma was established by the Asthma Control Questionnaire. Measurements and Main Results: The pH measurement was feasible in all samples and repeatable both within (intraclass correlation coefficient [ICC], 0.96) and between samples (ICC, 0.621). The mean pH was significantly different between healthy subjects and patients with asthma, including in those with controlled (mean pH: 7.54 in healthy subjects vs. 7.28 in subjects with controlled asthma; p = 0.0105) and uncontrolled disease (mean pH: 7.54 in healthy subjects vs. 7.06 in subjects with uncontrolled disease; p < 0.0001), and between patients with stable asthma and those with poorly controlled asthma (7.28 vs. 7.06, respectively; p = 0.0134). The validity of the method was assessed with the receiver operating characteristic curves and induced-sputum lower pH values (with a cutoff value of 7.3; sensitivity, 72.1%; specificity, 100%). Conclusions: Patients with asthma show lower pH than healthy subjects. Patients with poorly controlled asthma seem to have the lowest induced-sputum pH, independent of the GINA (Global Initiative for Asthma) severity level. In conclusion, induced sputum is a feasible, repeatable, noninvasive method to measure airway pH. The pH in induced sputum may reflect a different aspect of asthma from sputum eosinophils and be related to different pathophysiologic factors.