纤维支气管镜灌洗液Xpert MTB/RIF检测对肺结核诊断和利福平耐药菌株筛选的临床价值

The Clinical Value of Xpert MTB / RIF Test Todetect Mycobacterium Tuberculosis and Drug Resistance of Branchofiberoscope Lavage Fluid in Diagnosing of Tuberculosis

目的探讨利福平耐药实时荧光定量核酸扩增(Xpert MTB/RIF)技术对肺结核诊断和利福平耐药菌株筛选的价值。方法选取2014年4月至2015年4月武汉市结核病防治所收治的疑诊为肺结核的患者193例,进行纤维支气管镜(纤支镜)灌洗液抗酸涂片、结核培养以及Xpert MTB/RIF检测,对结果进行分析,以罗氏比例法药物敏感试验作为金标准对RIF耐药情况进行分析。结果193例疑诊肺结核患者中153例确诊和临床诊断为肺结核,其中结核培养阳性61例,结核培养阴性92例,余40例为非结核肺部疾病患者。纤支镜灌洗液抗酸涂片、结核培养和Xpert MTB/RIF检测结核分枝杆菌(MTB)诊断肺结核的灵敏度、特异度、阳性预测值、阴性预测值及准确度分别为20.3%、39.9%、62.1%;90.0%、95.0%、100.0%;88.6%、96.8%、100.0%;22.8%、29.2%、40.8%;34.7%、51.3%、69.9%。三种检测方法的受试者工作特征曲线曲线下面积分别为0.551、0.674、0.810,显示Xpert MTB/RIF检验诊断效能最大,与结核培养和抗酸涂片比较,差异均有统计学意义(P<0.01)。92份结核培养阴性标本经Xpert MTB/RIF方法检出MTB 35份,其中循环阈值为中等含量者7份,低含量16份,极低含量12份。Xpert MTB/RIF检测RIF耐药的灵敏度为100.0%(14/14),特异度为93.6%(44/47)。结论 Xpert MTB/RIF技术对结核辅助诊断的临床价值优于抗酸涂片和结核培养,在结核分枝杆菌及其对利福平耐药快速检测方面有良好的应用前景。

Objective To discuss the clinical value of Xpert MTB/RIF test in diagnosing pulmonary tuberculosis （FIB） and screening Rifampin resistant strains. Methods 193 suspected PTB patients were selected from Apr.2014 to Apr. 2015 in the Tuberculosis Prevention and Control institution of Wuham The acid-fast staining, mycobacterium culture test and Xpert MTB/RIF test of branchofiberoscope lavage fluid were all taken among them. Considering the results of conventional proportion method for the drug susceptibil- ity as golden standard,the results of three methods were compared respectively. Results 153 of 193 patients were clinically or definitely diagnosed as PTB ,while 61 of them had a positive result of mycobacterium cul- ture and 92 of them had a negative result. 40 of 193 patients were diagnosed as other pulmonary disease. The sensitivity, specificity, positive predictive value, negative predictive value, acc.uracy rate of acid fast strai- ning,mycobacterium culture and Xpert MTB/RIF of branchefiberescope lavage fluid were 20. 3% ,39. 9%, 62. 1% ;90. 0% ,95.0% ,100. 0% ;88. 6% ,96. 8% ,100. 0% ;22. 8% ,29. 2% ,40. 8% ;34. 7% ,51.3%, 69.9% ,respectively. Xport MTB/RIF test was superior to acid-fast staining and mycobacterium culture in all index except specificity. The difference was statistically significant （ P 〈 0. 05 ）. There were 62 patients had positive results of Xpert MTB/RIF in 92 patients who had negative results of mycohacterium culture. 7 of them was in moderate level of circulation threshold value of MTB, 16 of them was in low level of circulation threshold value of MTB, while 12 of them was in extremely low level of circulation threshold value of MTB. The sensitivity of RFP-resistance which was carried out by Xpert MTB/RIF test was 100. 0% （ 14/ 14）, while the specificity was 93.6% （44/47）, Conclusion The clinical value of Xpert MTB/RIF test was superiorto acid-fast staining smear test and mycobacterium culture in upplementary diagnosis of tubercu- losis. Application foreground of Xpert MTB/RIF test in quickly detecting MTB and RFP-resistance was looked forward.