Department of Pathology, University of Otago, and Department of Infectious Diseases, Christchurch Hospital, Christchurch, New Zealand.
Curr Opin Pulm Med. 2012 May;18(3):228-32. doi: 10.1097/MCP.0b013e328351f98b.
Breath testing has developed over the last 20 years. New techniques that can identify fingerprints for specific diseases and specific markers of respiratory pathogens have been applied to breath analysis. This review discusses the recent advances in breath analysis for the diagnosis of bacterial and fungal lower respiratory tract infections.
The current techniques continue to develop rapidly, but preconcentration techniques are needed to analyse many target volatile organic compounds for most systems. Breath testing with an electronic nose is promising for the diagnosis of tuberculosis (TB), and specific volatiles identifiable by gas chromatography with mass spectrometry have been identified in breath for Mycobacterium tuberculosis, Pseudomonas aeruginosa and Aspergillus fumigatus, but are found at very low concentrations in breath. Contamination from the environment is an ongoing confounding influence. Exhaled breath condensate (EBC) is disappointing as a diagnostic sample.
Careful attention needs to be paid to the sensitivity and specificity of a technique and confounding from the environment. The role of technologies such as selected ion flow tube-mass spectrometry is emerging. The electronic nose requires further validation for TB. The identification of specific microbial biomarkers aids the quest for improved accuracy. EBC is currently of limited value.
呼吸测试在过去 20 年中得到了发展。已经将能够识别特定疾病指纹和呼吸道病原体特定标志物的新技术应用于呼吸分析。本文讨论了用于诊断细菌和真菌下呼吸道感染的呼吸分析的最新进展。
目前的技术继续快速发展，但大多数系统都需要预浓缩技术来分析许多目标挥发性有机化合物。电子鼻呼吸测试对结核病（TB）的诊断很有前景，通过气相色谱-质谱法可识别结核分枝杆菌、铜绿假单胞菌和烟曲霉呼吸中的特定挥发性物质，但在呼吸中浓度非常低。来自环境的污染是一个持续存在的混杂因素。呼出气冷凝液（EBC）作为诊断样本令人失望。
需要仔细注意技术的敏感性和特异性以及环境的混杂因素。选择离子流管-质谱等技术的作用正在显现。电子鼻需要进一步验证用于结核病。鉴定特定的微生物生物标志物有助于提高准确性。目前 EBC 的价值有限。
