摘要目的 评估新一代结核分枝杆菌(Mycobacterium tuberculosis,MTB)/利福平(rifampin,RIF)耐药实时荧光定量核酸扩增(Xpert MTB/RIF Ultra)技术在快速检测MTB和RIF耐药中的临床应用价值.方法 2016年3月至2016年12月河南省胸科医院就诊的疑似肺结核和复治结核病患者,最终共111例纳入研究,其中结核发现组(case detection group,CDG)33例和耐药高风险组(drug resistant high-risk group,DRG)78例.收集患者痰标本,分析比较Xpert MTB/RIF Ultra技术与痰涂片、固体罗氏(Lowenstein-Jensen,L-J)培养、液体分枝杆菌(mycobacterial growth indicator tube,MGIT)培养和MTB/RIF耐药实时荧光定量核的扩增(Xpert MTB/RIF)技术检测MTB的灵敏度和特异度,采用Xpert MTB/RIF Ultra技术、表型药物敏感试验和Xpert MTB/RIF技术检测RIF耐药性.计数资料比较采用卡方检验,计量资料比较采用t检验.结果 以临床诊断为标准,CDG患者Xpert MTB/RIF Ultra技术检测MTB的灵敏度(75.8%)分别与痰涂片(66.7%)、L-J培养(63.6%)、MGIT培养(75.6%)、Xpert MTB/RIF技术(66.7%)比较,差异均无统计学意义(x2分别为0.67、1.15、0.00和0.67,均P>0.05).DRG患者Xpert MTB/RIF Ultra技术检测MTB的灵敏度(94.9%)优于L-J培养(55.1%)和MGIT培养(80.8%),差异均有统计学意义(x2分别为32.80和7.25,均P<0.05),与痰涂片(84.6%)和Xpert MTB/RIF技术(91.0%)比较差异均无统计学意义(x2分别为3.41和0.39,均P>0.05).Xpert MTB/RIF Ultra技术取得最终检测结果所需时间最短,为(1.76±0.18)h,与痰涂片[(5.04±0.49)h]、L-J培养[(31.67±0.56)d]、MGIT培养[(22.36±9.68)h]、Xpert MTB/RIF技术[(2.00±0.30)h]比较差异均有统计学意义(t分别为16.90、31.98、24.38和7.05,均P<0.01).以MTB培养阳性结果为标准,Xpert MTB/RIF技术和Xpert MTB/RIF Ultra技术检测MTB的灵敏度分别为93.2%和98.9%,特异度均为100%.在23例痰涂片阴性肺结核患者中,Xpert MTB/RIF Ultra技术灵敏度(52.2%)显著优于Xpert MTB/RIF技术(21.7%),差异有统计学意义(x2=4.98,P=0.025),特异度均为100%.以表型药物敏感试验结果为标准,44例有药物敏感试验结果的培养阳性患者中,以Xpert MTB/RIF和Xpert MTB/RIF Ultra技术检测RIF耐药的灵敏度分别为90.9%和93.2%,特异度分别为89.5%和92.9%.结论 在痰涂片阴性的肺结核患者中,采用Xpert MTB/RIF Ultra检测法比Xpert MTB/RIF检测法对MTB有更高的检出率.在耐药肺结核患者中,Xpert MTB/RIF Ultra检测法有较高的灵敏度,且所需时间较短,可快速检测出MTB及其对RIF的耐药性,具有很好的临床实用价值.

abstractsObjective To investigate the clinical value of a new-generation cartridge Xpert MTB/RIF Ultra assay on detection of Mycobacterium tuberculosis(MTB)and rifampin(RIF)resistance.Methods A total of 111 patients from He'nan Provincial Chest Hospital with suspected tuberculosis(TB)and retreated TB were enrolled into this study from March to December 2016,including 33 cases of tuberculosis detection group(CDG)and 78 cases of drug resistant high-risk group(DRG).The sputum samples of patients were collected.The sensitivity and specificity of Xpert MTB/RIF Ultra,sputum smear,solid Lowenstein-Jensen(L-J)culture and mycobacterial growth indicator tube(MGIT)culture for MTB were evaluated.RIF resistance was performed by Xpert MTB/RIF Ultra,traditional phenotypic drug sensitivity test and Xpert MTB/RIF assay.Measurement data were compared using t-test,and categorical data were compared using chi-squared test.Results Using clinical diagnosis result as the standard,in the CDG,the sensitivity of Xpert MTB/RIF Ultra for MTB detection(75.8%)was not significantly different from those of sputum smear(66.7%),L-J culture(63.6%),MGIT culture(75.6%)and Xpert MTB/RIF(66.7%)(x2=0.67,1.15,0.00 and 0.67,respectively,all P>0.05).In the DRG,the sensitivity of Xpert MTB/RIF Ultra(94.9%)was better than those of L-J culture(55.1%)and MGIT culture(80.8%)with statistical significance(x2=32.8 and7.25,respectively,both P <0.05).The sensitivity of Xpert MTB/RIF Ultra was not significantly different from sputum smear(84.6%)and Xpert MTB/RIF(91.0%)(x2=3.41 and 0.39,respectively,both P>0.05).Xpert MTB/RIF Ultra took the shortest time to obtain the final results,which was(1.76±0.18)h and significantly shorter than smear test([5.04±0.49]h),L-J culture([31.67±0.56]h),MGIT culture([22.36±9.68]h),Xpert MTB/RIF([2.00±0.30]h)(t=16.90,31.98,24.38 and 7.05,respectively,all P <0.01).Using culture result as the standard,the sensitivity for MTB detection of Xpert MTB/RIF and Xpert MTB/RIF Ultra were 93.2% and 98.9%,and the specificity of Xpert MTB/RIF and Xpert MTB/RIF Ultra were both 100%.The sensitivity for MTB detection of Xpert MTB/RIF Ultra(52.2%)was significantly better than that of Xpert MTB/RIF(21.7%)in 23 smear-negative pulmonary TB patients with statistical significance(x2=4.98,P=0.025).Using traditional drug susceptibility test as the standard,the sensitivities for RIF resistance detection of Xpert MTB/RIF and Xpert MTB/RIF Ultra in culture-positive TB patients were 90.9% and 93.2%,respectively,and the specificities were 89.5% and 92.9%,respectively.Conclusions Xpert MTB/RIF Ultra has a higher MTB detection rate than Xpert MTB/RIF in smear-negative pulmonary TB patients.In drug-resistant pulmonary TB patient,MTB/RIF Ultra has high sensitivity,and it takes shorter time to detect MTB and RIF resistance.Thus,Xpert MTB/RIF Ultra has a good application prospect in clinical work.