Jackson Abigail S, Sandrini Alessandra, Campbell Charlotte, Chow Sharron, Thomas Paul S, Yates Deborah H
Department of Thoracic Medicine, St. Vincent's Hospital, Victoria Street, Darlinghurst, Sydney, Australia.
Am J Respir Crit Care Med. 2007 Feb 1;175(3):222-7. doi: 10.1164/rccm.200601-107OC. Epub 2006 Nov 16.
Exhaled breath condensate (EBC) is increasingly studied as a noninvasive research method of sampling the lungs, measuring several biomarkers. The exact site of origin of substances measured in EBC is unknown, as is the clinical applicability of the technique. Special techniques might be needed to measure EBC biomarkers.
To assess biomarker concentrations in clinical disease and investigate the site of origin of EBC, we compared EBC and bronchoalveolar lavage (BAL) biomarkers in 49 patients undergoing bronchoscopy for clinical indications.
We measured exhaled nitric oxide, 8-isoprostane, hydrogen peroxide, total nitrogen oxides, pH, total protein, and phospholipid (n = 33) and keratin (n = 15) to assess alveolar and mucinous compartments, respectively. EBC was collected over 10 min using a refrigerated condenser according to European Respiratory Society/American Thoracic Society recommendations, and BAL performed immediately thereafter.
8-Isoprostane, nitrogen oxides, and pH were significantly higher in EBC than in BAL (3.845 vs. 0.027 ng/ml, 28.4 vs. 3.8 microM, and 7.35 vs. 6.4, respectively; p < 0.001). Hydrogen peroxide showed no difference between EBC and BAL (17.5 vs. 20.6 microM, p = not significant), whereas protein was significantly higher in BAL (33.8 vs. 183.2 microg/ml, p < 0.001). Total phospholipid was also higher in EBC, but keratin showed no difference. No significant correlation was found between EBC and BAL for any of the biomarkers evaluated either before or after correction for dilution.
In clinical disease, markers of inflammation and oxidative stress are easily measurable in EBC using standard laboratory techniques and EBC is readily obtained. However, EBC and BAL markers do not correlate.
呼出气冷凝液（EBC）作为一种对肺部进行采样、测量多种生物标志物的非侵入性研究方法，正受到越来越多的关注。EBC中所测物质的确切来源部位尚不清楚，该技术的临床适用性也不明确。测量EBC生物标志物可能需要特殊技术。
为评估临床疾病中的生物标志物浓度并探究EBC的来源部位，我们对49例因临床指征接受支气管镜检查的患者的EBC和支气管肺泡灌洗（BAL）生物标志物进行了比较。
我们分别测量了呼出一氧化氮、8-异前列腺素、过氧化氢、总氮氧化物、pH值、总蛋白以及磷脂（n = 33）和角蛋白（n = 15），以分别评估肺泡和黏液成分。根据欧洲呼吸学会/美国胸科学会的建议，使用冷藏冷凝器在10分钟内收集EBC，随后立即进行BAL。
EBC中的8-异前列腺素、氮氧化物和pH值显著高于BAL（分别为3.845对0.027 ng/ml、28.4对3.8 microM以及7.35对6.4；p < 0.001）。过氧化氢在EBC和BAL之间无差异（17.5对20.6 microM，p = 无显著性差异），而BAL中的蛋白质显著更高（33.8对183.2 microg/ml，p < 0.001）。EBC中的总磷脂也更高，但角蛋白无差异。在对稀释进行校正之前或之后，所评估的任何生物标志物在EBC和BAL之间均未发现显著相关性。
在临床疾病中，使用标准实验室技术可轻松测量EBC中的炎症和氧化应激标志物，且EBC易于获取。然而，EBC和BAL标志物不相关。
