结核分枝杆菌/利福平耐药实时荧光定量核酸扩增检测技术对肺外结核性脓肿的诊断价值分析

摘要 目的：探讨结核分枝杆菌/利福平耐药实时荧光定量核酸扩增检测技术（Xpert MTB/RIF）对肺外结核性脓肿的诊断价值。方法：收集2020年1月至2021年12月无锡市第五人民医院住院的122例高度疑似肺外结核性脓肿患者为研究对象，在超声引导下对脓肿病灶进行针吸穿刺活检，脓液标本分别进行Xpert MTB/RIF检测、结核杆菌脱氧核糖核酸（TB-DNA）检测、MGIT 960培养以及涂片抗酸染色。以临床综合诊断作为参考标准，比较Xpert MTB/RIF检测、TB-DNA检测、MGIT 960培养以及涂片抗酸染色四种方法对肺外结核性脓肿的诊断效能。对比Xpert MTB/RIF检测和MGIT 960药敏试验对利福平的耐药性。观察各类肺外结核性脓肿患者的诊断延迟时间。结果：122例疑似患者中，最终确诊肺外结核性脓肿患者73例，非结核性脓肿者49例。Xpert MTB/RIF检测、MGIT 960培养、TB-DNA检测以及涂片抗酸染色四种方法在肺外结核性脓肿标本中的阳性检出率结果分别为89.04%、20.55%、58.90%、36.99%，四种方法的阳性检出率整体比较差异有统计学意义（P<0.01），Xpert MTB/RIF检测的阳性检出率明显高于MGIT 960培养、TB-DNA检测以及涂片抗酸染色法，差异均有统计学意义（P<0.05）。以临床综合诊断作为参考标准，Xpert MTB/RIF检测诊断肺外结核性脓肿者的临床诊断价值最高，其敏感度、特异度、阳性预测值、阴性预测值分别为89.04%、100.00%、100.00%、85.96%。Xpert MTB/RIF检测与MGIT 960药敏试验对利福平耐药率之间差异无统计学意义（P>0.05）。肺外结核性脓肿诊断存在明显延迟，尤其以关节结核性脓肿诊断延迟时间最长，平均为103.5天；但在结核性脓胸患者中诊断延迟时间最短，平均为7.6天。结论：与MGIT 960培养、TB-DNA检测以及涂片抗酸染色比较，Xpert MTB/RIF在肺外结核性脓肿中的阳性检出率较高，临床诊断价值最佳，表明其可用作为疑似结核性脓肿患者的快速诊断工具，同时在结核耐药性方面亦可以做到快速筛查。

Diagnostic Value of Xpert Mycobacterium Tuberculosis/Rifampin in Extrapulmonary Tuberculous Abscess

ABSTRACT Objective: To explore the diagnostic value of Xpert Mycobacterium tuberculosis/Rifampin (Xpert MTB/RIF) in extrapulmonary tuberculous abscess. Methods: A total of 122 patients with highly suspected extrapulmonary tuberculous abscess hospitalized in Wuxi Fifth People''s Hospital from January 2020 to December 2021 were collected as the research objects. Needle aspiration biopsy was performed on the abscess focus under ultrasound guidance. The pus samples were tested for Xpert MTB/RIF detection,tubercle bacillus DNA(TB-DNA) detection, MGIT 960 culture and smear acid fast staining. Taking the comprehensive clinical diagnosis as the reference standard, the diagnostic efficacy of Xpert MTB/RIF detection, TB-DNA detection, MGIT 960 culture and smear acid fast staining for extrapulmonary tuberculous abscess was compared. Compare the resistance of Xpert MTB/RIF detection and MGIT 960 drug sensitivity test to rifampicin. To observe the diagnostic delay time of patients with various types of extrapulmonary tuberculous abscess. Results: Among 122 suspected patients, 73 patients with extrapulmonary tuberculous abscess and 49 patients with non tuberculous abscess were finally diagnosed. The positive detection rates of Xpert MTB/RIF detection, MGIT 960 culture, TB-DNA detection and smear acid fast staining in extrapulmonary tuberculous abscess samples were 89.04%, 20.55%, 58.90% and 36.99% respectively, and the overall difference in the positive detection rates of the four methods was statistically significant (P<0.01). The positive detection rate of Xpert MTB/RIF detection was significantly higher than that of MGIT 960 culture, TB-DNA detection and smear acid fast staining, the difference was statistically significant (P<0.05). Taking the clinical comprehensive diagnosis as the reference standard, Xpert MTB/RIF detection has the highest clinical diagnostic value in the diagnosis of extrapulmonary tuberculous abscess, its sensitivity, specificity, positive predictive value and negative predictive value were 89.04%, 100.00%, 100.00% and 85.96% respectively.There was no significant difference in rifampicin resistance between Xpert MTB/RIF detection and MGIT 960 drug sensitivity test (P>0.05). There was a significant delay in the diagnosis of extrapulmonary tuberculous abscess, especially the joint tuberculous abscess, with an average of 103.5 days; However, among patients with tuberculous empyema, the diagnosis delay time was the shortest, with an average of 7.6 days. Conclusion: Compared with MGIT 960 culture, TB-DNA detection and smear acid fast staining, Xpert MTB/RIF has a higher positive detection rate in extrapulmonary tuberculous abscess and the best clinical diagnostic value, indicating that it can be used as a rapid diagnostic tool for patients with suspected tuberculous abscess at the same time, it can also achieve rapid screening in terms of tuberculosis drug resistance.