GeneXpert Mtb/RIF检测技术在临床耐药结核病诊断中的应用价值

Application of GeneXpert Mtb/RIF assay for diagnosis of drug-resistant tuberculosis

关键词:  GeneXpert  结核病  耐药  快速诊断

Key words:  GeneXpert  tuberculosis  multidrug-resistant  rapid diagnosis

摘要:

目的 评估GeneXpert Mtb/RIF检测技术在临床耐药结核病诊断中的应用效果。方法 收取240例结核病住院患者的晨痰样本分别进行痰涂片镜检、MGIT960液体培养及GeneXpert Mtb/RIF快速检测,对于MGIT960液体培养与GeneXpert同为阳性的样本进一步进行MGIT960药敏检测。以MGIT960液体法作为金标准,评估GeneXpert Mtb/RIF检测技术的敏感性和特异性以及Kappa值。结果 224例有效样本中涂片镜检阳性检测率为26.8%,MGIT960液体培养阳性检出率为45.1%,GeneXpert检测阳性检出率为46.9%；以MGIT960液体培养作为金标准,涂片镜检法的敏感度为59.4%,特异度为75.0%,GeneXpert检测法敏感度为91.1%,特异度为92.4%；以MGIT960药敏检测为金标准,GeneXpert检测法与之相比两种方法的一致性为96.7%,敏感度为92.3%,特异度为98.5%。结论 GeneXpert Mtb/RIF检测技术是一个敏感、特异和快速有效方法,有利于结核病的早期诊断。

Abstract:

Objective To evaluate the application of GeneXpert MTB/RIF for clinical diagnosis of drug-resistant tuberculosis(TB). Methods Morning sputum samples from 240 TB inpatients were collected and tested with AFB smear, MGIT 960 system liquid culture and GeneXpert MTB/RIF. Drug susceptible testing(DST) was performed for samples with both positive MGIT960 liquid method and GeneXpert MTB/RIF assay. The liquid method was used as the gold standard to evaluate the sensitivity, specificity and the Kappa value for GeneXpert MTB/RIF assay. Results Among 224 valid samples, the positive detection rates were 26.8% for smear test, 45.1% for MGIT960 and 46.9% for GeneXpert MTB/RIF. With MGIT 960 liquid culture method as gold standard, the sensitivity and specificity of smear method were 59.4% and 75.0% while the sensitivity and specificity for GeneXpert MTB/RIF were 91.1% and 92.4% respectively. Compared with MGIT 960 DST testing, the concordance of GeneXpert MTB/RIF was 96.7%, with a sensitivity of 92.3% and a specificity of 98.5%. Conclusion GeneXpert Mtb/RIF is a rapid and effective method for diagnosis of drug-resistant TB cases.