Changes in sputum eosinophils predict less of asthma control
Changes in sputum eosinophils predict less of asthma control
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DOI：
10.1164/ajrccm.161.1.9809100
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发表时间：
2000-01-01
影响因子：
24.7
通讯作者：
Barnes, PJ
中科院分区：
文献类型：
--
作者：
Jatakanon, A;Lim, S;Barnes, PJ
哮喘的加重可能是由于气道炎症的增加。我们研究了减少吸入糖皮质激素剂量引起的哮喘急性发作中气道炎症的非侵入性标志物。在2周的导入期后，在用中等至高剂量吸入性皮质类固醇（二丙酸倍氯米松每日大于或等于800 μ g或等效剂量）控制的稳定哮喘受试者中，通过将其转换为从干粉吸入器（都保）每日给予200 μ g布地奈德，诱导轻度加重。15名受试者入组，在类固醇减量后每周两次，持续8周。在每次访问时，呼出的一氧化氮（NO），乙酰甲胆碱气道反应性进行了测量和肺功能测定和痰诱导。轻度急性发作定义为：（1）与导入期最后7天的平均值相比，至少连续两天的晨间呼气峰流量（PEF）降低大于或等于20%但< 30%;（2）连续两个晚上因哮喘而醒来;或（3）增加短效β（2）受体激动剂的使用，每天8次或更多。8例受试者在8周研究期间未发生急性加重，而7例受试者在第4周（n = 1）、第6周（n = 1）和第8周（n = 5）发生轻度急性加重。这两组在基线时的唯一显著差异是随后加重的受试者的基线痰嗜酸性粒细胞计数较高（p < 0.05）。痰嗜酸性粒细胞和呼出气NO的增加与气道功能的降低相关，包括早晨PEF和FEV 1的降低。然而，多元回归分析表明，痰嗜酸性粒细胞的变化是一个潜在的有用的标志物，在预测哮喘控制的损失反映了气道功能的损失。
Exacerbations of asthma are likely to be due to an increase in airway inflammation. We have studied noninvasive markers of airway inflammation in asthma exacerbations induced by reducing the dose of inhaled corticosteroids. Following a 2-wk run-in period, mild exacerbations were induced in subjects with stable asthma controlled with medium- to high-dose inhaled corticosteroids (beclomethasone dipropionate greater than or equal to 800 mu g or equivalent daily) by switching them to budesonide 200 mu g daily given from a dry-powder inhaler (Turbohaler). Fifteen subjects were enrolled and were seen twice weekly for 8 wk after steroid reduction. At each visit, exhaled nitric oxide (NO), and methacholine airway responsiveness were measured and spirometry and sputum induction were performed. Mild exacerbation was defined as: (1) a decrease in morning peak expiratory flow (PEF) of greater than or equal to 20% but < 30% on at least two consecutive days as compared with the mean for the last 7 d of the run-in period; (2) awakening on two consecutive nights because of asthma; or (3) increased use of a short-acting beta(2)-agonist to eight or more puffs daily. Eight subjects did not develop exacerbations during the 8-wk study, whereas seven subjects developed mild exacerbations at Week 4 (n = 1), Week 6 (n = 1), and Week 8 (n = 5). The only significant difference between these two groups at baseline was a higher baseline sputum eosinophil count in subjects with subsequent exacerbations (p < 0.05). The increases in sputum eosinophils and exhaled NO were correlated with decreases in airway function, including decreases in morning PEF and FEV1. However, multiple regression analysis suggested that the change in sputum eosinophils is a potentially useful marker in predicting loss of asthma control reflected by loss of airway function.