酶联免疫斑点法检测在涂阴肺结核患者的诊断价值

Diagnostic value of enzyme-linked immunospot assay in patients with sputum-acid-fast-bacilli-smear negative tuberculosis

目的评价肺泡灌洗液酶联免疫斑点试验(ELISPOT)在痰涂片抗酸杆菌阴性(涂阴)肺结核患者的诊断价值。方法应用ELISPOT检测32例涂阴肺结核患者、30例非结核肺部疾病患者外周血和肺泡灌洗液中分泌结核抗原特异性干扰素的T淋巴细胞水平;绘制受试者工作特征曲线(ROC),计算曲线下面积,比较两者的诊断价值。涂阴肺结核患者的肺泡灌洗液分别进行涂片抗酸染色、分枝杆菌培养、结核分枝杆菌核酸扩增荧光检测,比较其阳性率。结果在32例涂阴肺结核患者和30例非结核肺部疾病患者中,血ELISPOT检测的敏感性和特异性分别为84.4%、90.0%,肺泡灌洗液ELISPOT检测的敏感性和特异性分别为90.6%、96.7%,两者的差异无统计学意义(P>0.05);肺泡灌洗液、血ELISPOT检测ROC曲线下面积为0.936、0.872。涂阴肺结核肺泡灌洗液ELISPOT检测阳性率(90.6%)明显高于肺泡灌洗液抗酸染色(15.6%)、分枝杆菌培养(34.4%)和结核分枝杆菌核酸扩增荧光检测(31.3%),差异均有统计学意义(P均=0.000)。结论 ELISPOT检测肺泡灌洗液中分泌结核抗原特异性干扰素γ的T淋巴细胞水平,具有敏感、特异、快速等优点,可成为涂阴肺结核的辅助诊断方法。

Objective To study the diagnostic value of enzyme-linked immunospot assay（ELISPOT） for antigens specific interferon-γ in mycobacterium tuberculosis in bronchoalveolar lavage fluid（BALF）for sputum-acid-fast-bacillismear negative tuberculosis. Methods The ELISPOT tests were tested in 32 cases of sputum-acid-fast-bacilli-smear negative tuberculosis,and in 30 cases of nontuberculosis with other pulmonary diseases. Receiver operating characteristic（ROC） curve of ELISPOT in peripheral blood and in BALF were drawn,area under curve（AUC） was calculated and their diagnostic value was compared by AUC. BALF in sputum-acid-fast-bacilli-smear negative tuberculosis was also detected by acid fast stain, mycobacterium tuberculosis culture, nucleic acid amplification technique. Results In the tuberculosis group and nontuberculosis group, the ELISPOT sensitivity and specificity were 84.4% and 90.0% in peripheral blood,90.6% and 96.7% in BALF, but the difference was not statistically significant（P〉0.05）. The AUC of ROC was 0.936 in BALF and 0.872 in peripheral blood. The positive rate of ELISPOT in BALF of the 32 patients with sputum-acid-fast-bacilli-smear negative tuberculosis（90.6%） was higher than acid fast stain（15.6%）, mycobacterium tuberculosis culture（34.4%）, mycobacterium tuberculosis nucleic acid amplification fluorescence detection（31.3%）. The difference was statistically significant（P = 0.000）. Conclusion Detecting T lymphocytes which secrete tuberculosis antigens specific interferon-γ by ELISPOT in BALF is sensitive, specific and fast. It will become an auxiliary diagnostic method in sputum of AFB smear-negative tuberculosis