Xpert MTB/RIF技术在肺结核诊断中的应用价值

Application of Xpert MTB/RIF Detection Test in the Diagnosis of Tuberculosis

目的探究Xpert MTB/RIF(结核分支杆菌/利福平)技术在肺结核诊断中的应用价值。方法使用Xpert MTB/RIF技术、抗酸染色涂片镜检、罗氏固体培养法对147例疑似肺结核初诊患者进行诊断,评价Xpert MTB/RIF技术检测MTB的敏感度和特异性、与金标准的一致性。结果三种诊断方法阳性率分别为抗酸染色涂片法30.61%,罗氏固体培养法38.10%,Xpert MTB/RIF法42.18%,Xpert MTB/RIF阳性率显著高于抗酸法,但与罗氏固体培养法相当(2=4.246 4,0.509 6)。以罗氏固体培养结果为金标准,Xpert MTB/RIF对涂阳患者敏感度更高(100%vs 94.12%),但对涂阴样本的特异度高于涂阳患者(33.33%vs 92.31%);全部样本敏感度为98.21%,特异度为92.31%,阳性预测值为88.71%,阴性预测值为98.82%,kappa=0.887。Xpert MTB/RIF与金标准对痰样本分级一致性适中(kappa=0.579),差异不显著(u=0.820 9,P=0.411 7)。结论 Xpert MTB/RIF技术检测肺结核阳性率、敏感度与特异度均较高,对痰样本带菌量分级与罗氏固体培养法相仿,但其检测周期短,生物安全性高,可作为临床参考。

Objective To analyze the application value of Xpert MTB/RIF test in detection of tuberculosis and ri- fampin resistance. Methods MTB/RIF technology, anti - acid staining smear microscopy, Roche solid culture methods were used to diagnose 147 cases of suspected tuberculosis. The sensitivity, specificity and consistency to the Gold standard of Xpert MTB/RIF test to detect the MTB were analyzed. Results The positive rates of anti - acid staining smear microscopy, Roche solid culture methods and Xpert MTB/RIF were 30. 61%, 38.10%, 42. 18% by clinical diagnosis as gold standard. The positive rates of Xpert MTB/RIF assay was higher than that of acid - fast stain, hut no statistical significance between Roche solid culture method （ X^2 = 4. 246 4 and O. 509 6） was observed. Regarding solid culture as the gold standard, the sensitivity of the Xpert MTB/RIF test was significantly higher in Smear positive TB patients （ 100% vs 94. 12% ）, but sensi- tivity for smear- negative sample is higher than the smear- positive patients （33.33% vs 92. 31% ）; The sensitivity was 98.21%, specificity was 92. 31%, positive predictive value was 88. 71%, negative predictive value was 98.82%, the kappa = 0. 887 for all sample. The classification consistency between MTB/RIF and gold standard in sputum samples classification was moderate （ kappa = O. 579）, with no significant difference （ u = 0. 820 9, P = 0. 411 7）. Conclusion Xpert MTB/RIF tech- nology operation has a high positive rate, sensitivity and specificity in detection of MTB, the classification pathogen of sputum samples was similar to Roche culture method, with simple and rapid detection, which is suitable for the promotion of tubercu- losis elinie~.