Xpert MTB/RIF技术在基层实验室结核病诊断中的应用研究

Application research of Xpert MTB/RIF test for diagnosis of tuberculosisin in the primary laboratory

目的评估结核分枝杆菌/利福平耐药实时荧光定量核酸扩增检测技术(Xpert MTB/RIF)在基层实验室结核病诊断中的可行性与准确性。方法对1 042例来自区级结核病防治单位门诊初诊者的痰液样品,分别进行涂片镜检、固体培养、传统比例法药敏试验和Xpert MTB/RIF检测,分析比较Xpert MTB/RIF法和传统方法检测痰标本中的Mtb及其耐药性的敏感度、特异度及检测耗时。结果以固体培养试验结果作为金标准,Xpert Mtb/RIF方法检测痰标本Mtb的敏感度和特异度分别93.7%(655/699)和87.5%(300/343)。以传统比例法药敏试验结果为金标准,Xpert Mtb/RIF方法检测利福平耐药的敏感度和特异度分别为86.8%(79/91)和95.3%(531/557)。Xpert MTB/RIF系统平均检测耗时为2 h。结论 Xpert Mtb/RIF检测操作简单、快速,检测敏感度高于涂片镜检法,与固体培养法有极好的一致性,同时该方法可以诊断患者是否对利福平耐药,在我国县(区)级实验室具有非常好的应用前景。

Objective To investigate the feasibility and accuracy of Xpert MTB/RIF assay in the diagnosis of tuberculosis in primary laboratory. Methods 1 042 sputum samples from patients with clinically suspected tuberculosis from clinics in Shenzhen were collected. And the sensitivity, specificity and test time of different detection methods, including smear test, solid culture, traditional proportion method drug susceptibility test, and Xpert MTB/RIF test, in the detection rate of mycobacterium tuberculosis （MTB） and rifampicin resistance, were analyzed. Results Compared with the results of the solid culture test, the sensitivity and specificity of the Xpert MTB/RIF for MTB respectively were 93.7% （655/699） and 87.5% （300/343）. Compared with the results of traditional proportion method drug susceptibility test, the sensitivity and specificity of the Xpert MTB/RIF for in the detection rate of rifampicin resistance respectively were 86.8% （79/91） and 95.3% （531/557）, and the mean of test time of Xpert MTB/RIF was 2.1 hours （range, 1.8-2.6 hours）. Conclusion Compared with other test methods, Xpert MTB/RIF test significantly improved the diagnositic sensitivity and specificity for MTB. Xpert MTB/RIF test can be used to detect rifampicin resistance. And Xpert MTB/RIF test will provide a specific method for the early diagnosis of tuberculosis.