宏基因组二代测序对不同类型结核病的诊断价值

Application value of metagenomic next-generation sequencing(mNGS)in the diagnosis of different types of tuberculosis

目的研究宏基因组二代测序技术(mNGS)对不同类型结核病的诊断价值。方法回顾性分析2019年1月1日至12月31日上海市肺科医院收治的行mNGS检测并行结核分枝杆菌(MTB)抗酸染色涂片法、MTB培养法及利福平耐药实时荧光定量核酸扩增检测技术(Xpert MTB/RIF)检测的疑似结核病患者,研究共纳入疑似结核病205例,男120例,女85例,中位年龄为34(16,70)岁。其中结核病165例,男92例,女73例,中位年龄30(12,67)岁;非结核病40例,其中感染性疾病28例,恶性肿瘤12例,男28例,女12例,中位数年龄45(24,78)岁。以最终诊断为参考标准,计算mNGS对不同类型的结核病(肺结核与肺外结核)及与不同诊断方法诊断效率的差异,P<0.05为差异有统计学意义。结果以临床诊断结果作为参考标准,mNGS诊断结核病的敏感度为60%(99/165,95%CI为0.53~0.67),特异度为100%(40/40,95%CI为0.90~1.00),阳性预测值为100%(99/99,95%CI为0.95~1.00),阴性预测值为38%(40/106,95%CI为0.29~0.48)。mNGS诊断肺结核的敏感度为59%(59/100),显著高于涂片法(15%,15/100)和培养法(26%,26/100),差异均有统计学意义(均P<0.001),但与Xpert法(52%,52/100)比较差异无统计学意义(P=0.090);mNGS诊断肺外结核的敏感度为62%(40/65),显著高于涂片法(5%,3/65)、Xpert法(31%,20/65)及培养法(18%,12/65),三者比较差异均有统计学意义(均P<0.001)。结论mNGS法检测MTB快速、高效,对于结核病特别是肺外结核病的诊断优于其他常用的诊断方法。

Objective To investigate the diagnostic value of metagenomic next generation sequencing(mNGS)for different types of tuberculosis(TB).Methods A retrospective analysis was performed on suspected TB patients admitted to Shanghai Pulmonary Hospital from January 1,2019 to December 31,2019.The patients underwent mNGS test,acid-fast staining smear,Mycobacterium tuberculosis(MTB)culture and Xpert MTB/RIF(Xpert).A total of 205 TB suspects were finally included,including 120 males and 85 females,with a median age of 34(16,70)years.There were 165 cases of TB,including 92 males and 73 females,with a median age of 30(12,67)years.There were 40 non-TB patients,28 males and 12 females,with a median age of 44.6(24,78)years,including 28 cases of infectious diseases and 12 cases of malignant tumors.With the final diagnosis as the reference standard,the diagnostic efficiency of mNGS in different types of tuberculosis(including pulmonary tuberculosis and extrapulmonary tuberculosis)and differences in diagnostic sensitivities between mNGS and other detection methods were calculated,respectively.P<0.05 was considered to be statistically different.Results With clinical diagnosis as the reference standard,the sensitivity of mNGS to diagnose TB in this study was 60%(99/165,95%CI:0.53-0.67),and the specificity was 100%(40/40,95%CI 0.90-1.00).The positive predictive value was 100%(99/99,95%CI:0.95-1.00),and the negative predictive value was 37.74%(40/106,95%CI:0.29-0.48).The sensitivity of mNGS in TB was 60%(99/165),higher than that of smear(10.9%,18/165),Xpert(43.64%,72/165)and culture(23.03%,38/165).All the differences were statistically significant(P=0.00).The sensitivity of mNGS in pulmonary TB was 59%(59/100),which was significantly higher than that of smear(15%,15/100)and culture(26%,26/100),all P<0.001,but the difference was not statistically significant compared with Xpert(52%,52/100,P=0.09).In the extrapulmonary tuberculosis(EPTB),the sensitivity of mNGS was 61.54%(40/65),higher than that of acid fast staining(4.62%,3/65),Xpert(30.77%,20/65)and culture(18.45%,12/65).All the differences were statistically significant(all P<0.001).Conclusion The mNGS was rapid and efficient in detection of MTB,and was superior to other traditional diagnostic methods for TB,especially for EPTB.