GeneXpert MTB/RIF技术对结核病及对利福平耐药性检测的价值

The value of GeneXpert MTB/RIF technology in tuberculosis detection and resistance to rifampin

目的分析基层结核病防治所采用GeneXpert MTB/RIF(简称"GeneXpert")技术对结核病及其对利福平耐药性检测的可行性。方法回顾性分析2019年1月1日至12月31日就诊于北京市昌平区结核病防治所的全部肺结核可疑症状者,共计1719例。对1719例肺结核可疑症状者开展痰涂片、罗氏固体培养、GeneXpert检查,其中经临床和实验室检测结果证实为其他疾病的患者587例,非活动性肺结核患者550例,共确诊582例活动性肺结核患者。582例活动性肺结核患者中,237例患者有实验室病原学依据(同一例患者同一份痰标本同时经过罗氏固体培养后采用结核分枝杆菌MPB64抗原进行菌种鉴定,以及采用GeneXpert检测系统进行检测),诊断为病原学阳性患者,其余345例患者为临床诊断患者。对237例患者的痰标本分别进行阳性检出率的比较,以及采用罗氏固体比例法和GeneXpert技术对利福平耐药性进行检测。采用χ^2检验对计数资料进行比较;当理论频数小于5时,采用Fisher精确概率法进行比较,以P<0.05为差异有统计学意义。结果237例病原学阳性患者中,痰涂片阳性检出率为25.3%(60/237),罗氏固体培养为79.7%(189/237),GeneXpert技术为96.2%(228/237);GeneXpert的阳性检出率明显高于罗氏固体培养和痰涂片检查,差异均有统计学意义(χ^2=249.742,P<0.001;χ^2=30.332,P<0.001)。以罗氏固体比例法利福平耐药性检测结果为参考标准,GeneXpert技术对利福平耐药的敏感度、特异度、阳性预测值、阴性预测值、一致率分别为99.6%(232/233)、100.0%(4/4)、100.0%(232/232)、80.0%(4/5)、99.6%(236/237)。结论GeneXpert技术对病原学阳性患者的检出率和对利福平耐药性检出率均较高,对基层开展结核病检测及耐利福平结核病检测具有较高的价值。

Objective To analyze the feasibility of GeneXpert MTB/RIF technology to detect tuberculosis(TB)and resistance to rifampin in basic TB control institutions.Methods Retrospective analysis was performed on all patients with suspected symptoms of TB who visited Changping Institute for Tuberculosis Control and Prevention from January 1 st to December 31 st,2019,which was a total of 1719 cases.Sputum smears,Roche solid culture,and GeneXpert tests were performed on the 1719 patients.Among them,587 patients with other diseases were confirmed by clinical and laboratory test results,550 patients with inactive TB were diagnosed and 582 active cases were diagnosed.Among the 582 active TB cases,237 patients had laboratory etiological evidence(the same sputum sample of the same patient was also cultured by Roche and the M.tuberculosis MPB64 antigen was used for strain identification,and the GeneXpert detection system was used as well),was diagnosed as etiological positive patient,and the remaining 345 patients were clinically diagnosed patients.The positive detection rates of sputum specimen of the 237 TB cases by smear,culture and GeneXpert were compared,and rifampin resistance related indexes were compared as well.Chi-square test was used to compare the count data.When the theoretical frequency was lower than 5,the Fisher exact probability method was used for comparison.The difference was statistically significant with P <0.05.Results Of 237 etiologically positive patients,the detection rates were 25.3%(60/237),79.7%(189/237)and 96.2%(228/237)by smear,culture and GeneXpert,respectively.The detection rate of GeneXpert was significantly higher than that of culture and smear(χ2=249.742,P<0.001;χ2=30.332,P<0.001).Took Roche solid ratio method rifampicin resistance test result as the reference standard,the sensitivity,specificity,positive predictive value,negative predictive value and consistency were 99.6%(232/233),100.0%(4/4),100.0%(232/232),80.0%(4/5)and 99.6%(236/237)respectively.Conclusion GeneXpert has a high detection rate for etiologically positive patients and rifampin resistance.It is of great value to carry out TB detection and rifampin resistant TB detection at the basic level.