痰标本PCR-反向斑点杂交法对疑似非结核分枝杆菌肺病的诊断价值

The diagnostic value of sputum PCR-reverse dot blot hybridization in the diagnosis of suspected NTM pulmonary disease

目的 探讨痰PCR-反向斑点杂交法对疑似非结核分枝杆菌（NTM）肺病的诊断价值。方法 搜集2014年1月至2017年10月同济大学附属上海市肺科医院收治的、通过临床症状和影像学检查疑诊为NTM肺病的患者334例,分别取痰液行PCR-反向斑点杂交法分枝杆菌菌种鉴定基因检测及分枝杆菌传统培养法[对硝基苯甲酸（PNB）、噻吩-2-羧酸肼（TCH）培养基生长试验]检测,最终确诊为NTM肺病患者218例（NTM肺病组）、结核病患者42例（结核病组）、其他肺部疾病患者74例（研究中予以排除）。以最终确诊结果为金标准,对痰PCR-反向斑点杂交法诊断临床疑诊NTM肺病患者的敏感度、特异度、阳性预测值和符合率进行分析。结果 疑诊NTM肺病的334例患者中,培养法分枝杆菌检出率为67.66%（226/334）,PCR-反向斑点杂交法分枝杆菌检出率为64.67%（216/334）,两种方法分枝杆菌检出率的比较,差异无统计学意义（χ^2=0.67,P=0.231）。确诊的218例NTM肺病患者中,PCR-反向斑点杂交法检出NTM的敏感度为82.57%（180/218）,阳性预测值为98.36%（180/183）;培养法检出NTM的敏感度为87.61%（191/218）,阳性预测值为100.00%（191/191）;两种方法检出NTM的敏感度比较,差异无统计学意义（χ^2=1.20,P=0.169）。以42例结核病组患者作为对照,PCR-反向斑点杂交法检测的特异度为78.57%（33/42）,诊断结核病的阳性预测值为100.00%（33/33）;培养法的特异度为83.33%（35/42）,诊断结核病的阳性预测值为100.00%（35/35）;两种检测方法特异度的比较,差异无统计学意义（χ^2=0.31,P=0.391）。PCR-反向斑点杂交法在两组患者中的诊断符合率为83.08%（216/260）,培养法在两组患者中的诊断符合率为86.92%（226/260）,差异无统计学意义（χ^2=1.51,P=0.134）。 结论 以胸部CT检查为诊断基础的疑似NTM肺病患者中,应用PCR-反向斑点杂交法行痰液NTM检测具有较高的敏感度和特异度,对临床的快速准确诊断和及时治疗有一定的参考意义。

Objective To investigate the diagnostic value of sputum PCR-reverse dot blot （RDB） hybridization in the diagnosis of suspected NTM pulmonary disease.Methods Three hundred and thirty four cases of suspected NTM pulmonary disease were selected from January 2014 to October 2017 at the Shanghai Pulmonary Hospital Affiliated to Tongji University School of Medicine based on respiratory symptoms and thoracic CT findings. Sputum samples were collected and underwent PCR-RDB hybridization Mycobacterium species identification, and traditional PNB-TCH growth culture, 218 patients were diagnosed with NTM pulmonary disease （NTM pulmonary disease group）, 42 with tuberculosis （TB group）, and 74 with other lung diseases （excluded from the study）. The sensitivity, specificity, positive predictive values and conformity rate of PCR-RDB were calculated.Results The positive culture detection rate for the 334 cases of suspected NTM pulmonary disease was 67.66% （226/334）, while the PCR-RDB detection rate was 64.67% （216/334）. Differences in the results for the two methods were not statistically significant （χ^2=0.67, P=0.231）. The sensitivity of PCR-RDB and culture for the 218 cases of NTM pulmonary disease was 82.57% （180/218） and 87.61% （191/218）, respectively, and no statistically significant difference between the two methods was found （χ^2=1.20, P=0.169）. The positive predictive values for PCR-RDB and culture were 98.36% （180/183） and 100.00% （191/191）, respectively. The specificity of PCR-RDB and culture for the 42 cases of TB was 78.57% （33/42） and 83.33% （35/42）, respectively, and no statistically significant difference was found （χ^2=0.31, P=0.391）.The positive predictive values of PCR-RDB and culture for diagnosing TB were 100.00% （33/33） and 100.00% （35/35）, respectively. The conformity rate of PCR-RDB was 83.08% （216/260）, and that of culture was 86.92% （226/260）, and no statistically significant difference was found （χ^2=1.51, P=0.134）. Conclusion Sputum PCR-RDB hybridization has high sensitivity and specificity and is a simple and rapid method that can be used to identify bacteria directly. It is a helpful guide for clinicians during diagnosis and may lead to more rapid and accurate treatment.