荧光定量聚合酶链反应检测在肺结核诊断中的应用价值

目的分析荧光定量聚合酶链反应(PCR)检测支气管肺泡灌洗液(BALF)中结核分枝杆菌脱氧核糖核酸(TbDNA)在诊断肺结核中的应用价值。方法选择2018年1月-2020年1月湖南省儿童医院收治的21例肺结核患儿作为肺结核组,另外选择同时期21例排除肺结核感染的肺部疾病患儿作为非肺结核组。全部患儿均行痰涂片抗酸染色镜检、纤维支气管镜(纤支镜)痰涂片抗酸染色镜检和BALF中TbDNA荧光定量PCR检测。比较3种检测方法对肺结核诊断的特异度、敏感度、阳性预测值(PPV)和阴性预测值(NPV)。结果痰涂片抗酸染色镜检、纤支镜痰涂片抗酸染色镜检和荧光定量PCR的敏感度分别为19.05%、14.29%、76.19%,特异度分别为100.00%、100.00%、95.24%,PPV分别为100.00%、100.00%、94.12%,NPV分别为55.26%、53.85%、80.00%。荧光定量PCR检测BALF中TbDNA的敏感度明显高于痰涂片抗酸染色镜检和纤支镜痰涂片抗酸染色镜检(76.19%比19.05%、14.29%),差异有统计学意义(P<0.05);3种检测方法的特异度比较差异无统计学意义(P>0.05)。结论通过荧光定量PCR检测BALF中的TbDNA,具有快速、敏感度高、特异度高的特点,利于早期诊断肺结核,尤其是对于痰涂片检测呈阴性及无典型影像学特征的患儿,可以明显提高确诊率,其结果能够作为诊断肺结核的主要指标。

Application value of fluorescence quantitative polymerase chain reaction in diagnosis of pulmonary tuberculosis

Objective To analyze the value of fluorescence quantitative polymerase chain reaction(FQ-PCR) in the detection of Mycobacterium tuberculosis DNA (TbDNA) in bronchoalveolar lavage fluid (BALF) in the diagnosis of pulmonary tuberculosis infection.Methods From January 2018 to January 2020,21 children with pulmonary tuberculosis admitted in Hunan Children’s Hospital were selected as tuberculosis group,and 21 children with pulmonary diseases excluded from tuberculosis infection in the same period were selected asnon-tuberculosis group.All patients were examined by sputum smear acid fast staining microscopy,bronchoscopysputum smear acid fast staining microscopy and FQ-PCR detection of TbDNA in BALF.The specificity,sensitivity,positive predictive value (PPV) and negative predictive value (NPV) of three methods were compared.Results Using sputum smear acid fast staining microscopy,bronchoscopy sputum smear acid fast staining microscopy and FQ-PCRdetection,the sensitivity was 19.05%,14.29%,76.19%,specificity was 100.00%,100.00%,95.24%,PPV was 100.00%,100.00%,94.12%,and NPV was 55.26%,53.85%,80.00%.The sensitivity of FQ-PCR detection was significantly higher than those of sputum smear acid fast staining microscopy and bronchoscopy sputum smear acid fast staining microscopy (76.19% vs.19.05%,14.29%),with significant difference (P < 0.05),while the specificity of three methods had no significant difference (P > 0.05).Conclusions The detection of TbDNA in BALF by FQ-PCRis fast,sensitive and specific,which is helpful for the early diagnosis of pulmonary tuberculosis,especially for the children with negative sputum smear result and without typical imaging features.It can significantly improve the diagnosis rate,and the results can be used as the main basis for the diagnosis of pulmonary tuberculosis.