摘要目的:探讨宏基因组二代测序(mNGS)技术检测支气管肺泡灌洗液(BALF)的病原微生物在异常肺部影像诊断中的临床应用价值。方法:回顾性研究。空军特色医学中心2018年9月至2020年11月收治的58例异常肺部影像患者的临床资料，BALF均行mNGS检测和常规病原微生物检测(普通细菌及真菌培养，涂片包括：抗酸染色、Grocntt六胺银染色、吉姆萨染色，病毒核酸检测)，比较2种方法在病原检测上的特点。结果:确诊为感染性肺部疾病42例(感染组)，非感染性肺部疾病16例(非感染组)，感染组BALF中的中性粒细胞百分比高于非感染组( P<0.05)；mNGS检测病原微生物的检出率(81.0%，47/58)明显高于常规方法(8.6%，5/58)，差异有统计学意义( χ2＝61.486， P<0.001)。mNGS的检测时间少于常规方法(2.00±0.01) d比(3.25±0.50) d( P＝0.002)；mNGS的检测法较常规检测法检测病原的敏感度、准确度、阴性预测值均较高，假阴性较低，88.1%比9.5%、74.1%比32.8%、54.5%比28.3%、11.9%比90.1%。 结论:异常肺部影像患者，mNGS检测技术检测BALF中病原微生物检出率、敏感度、准确度高，结合临床，可快速且精准诊断，阴性结果有排除感染性疾病的价值。

abstractsObjective:To analyze the metagenomic next-generation sequencing (mNGS) of pathogenic microorganism in bronchoalveolar lavage fluid (BALF) from patients with abnormal lung imaging, and to demonstrate the diagnostic value of mNGS in the patients.Methods:A retrospective study was performed in 58 patients with abnormal lung imaging were recruited between September 2018 and November 2020 from our hospital.The differences in the pathogens in BALF were analyzed by mNGS and conventional method (including bacteria, fungus, acid-fast staining, hexamine silver staining, etc).Results:There were 42 patients with pulmonary infection (infected group) and 16 patients without pulmonary infection (non-infected group). The percentage of neutrophils in BALF of infected group was higher than that of non-infected group ( P<0.05). The detection rate of mNGS (81.0%, 47/58 respectively) was significantly higher than that of conventional microbiological detection (8.6%, 5/58)( χ2=61.486, P<0.001). The detection days of mNGS were less than those of conventional microbiological detection (2.00±0.01) vs (3.25±0.50) d( P=0.002). Compared with conventional method, mNGS method had higher sensitivity, accuracy, and lower false negative rate 88.1% vs 9.5%, 74.1% vs 32.8%, 54.5% vs 28.3%, 11.9% vs 90.1%. Conclusions:mNGS could quickly detect the BALF pathogens in the patients with abnormal lung imaging, with significant higher sensitivity, detection rate and accuracy.Combined with clinical manifestations, mNGS could be used as a fast and accurate diagnosis method.After removing the possible factors, negative results have the value of infectious disease exclusions.