T-SPOT.TB在肺结核早期诊断中的应用研究

Application of T-SPOT.TB in the Early Diagnosis of Tuberculosis

目的探讨结核感染T淋巴细胞酶联免疫斑点试验(tuberculosis T lymphocytes enzyme-linked immune SPOT test,T-SPOT.TB)在肺结核早期诊断中的应用价值。方法采用T-SPOT.TB,荧光定量PCR(fluorescence quantitative PCR,RQ-PCR)、结核蛋白芯片(TB-Ab protein chip)及结核菌素试验(purified protein derivative,PPD)检测189例疑似肺结核患者是否有结核菌感染。结果 T-SPOT,PCR,TB-AB和PPD方法的敏感度分别为91.54%(119/130),73.85%(96/130),63.08%(82/130)及57.69%(75/130),特异度分别为89.83%(53/59),86.44%(51/59),67.79%(40/59)及66.10%(39/59);T-SPOT.TB方法敏感度均高于荧光定量PCR法等三种方法(x^2=14.216~41.573,均P<0.05),TSPOT.TB方法特异度均高于PPD试验及结核蛋白芯片方法(x^2=8.577~9.669,P<0.05);T-SPOT.TB,荧光定量PCR,TB-Ab及PPD阳性预测值分别为95.2%(119/125),92.3%(96/104),81.2%(82/101)和78.9%(75/95).而阴性预测值分别为82.8%(53/64),60%(51/85),45.5%(40/88)和41.5%(39/94);四种检测方法的假阳性率(误诊率)分别为10.2%(6/59),13.6%(8/59),32.2%(19/59)和33.9%(20/59),而假阴性率(漏诊率)分别为8.5%(11/130),26.2%(34/130),36.9%(48/130)和42.3%(55/130);四种检测方法的阴性似然比分别为0.11,0.16,0.48和0.51,而阳性似然比分别为9.0,5.4,2.0和1.7;四种检测方法的诊断符合率分别为91.0%(172/189),77.8%(147/189),64.6%(122/189)和60.3%(114/189);T-SPOT.TB,荧光定量PCR,TB-Ab及PPD的约登指数分别为0.81,0.60,0.31和0.24。结论在实验室检测早期结核菌感染的方法中T-SPOT.TB检测法是较敏感且特异度较高的方法,对不同阶段肺结核诊断更具临床应用价值。

Objective This study aims to explore the application value of tuberculosis T lymphocytes enzyme-linked immune SPOT test （T-SPOT. TB） on early diagnosis of tuberculosis. Methods The TB infection in 189 inpatients suspected tuber- culosis in pneumology department of Shaanxi Provincial People＇s Hospital was detected with T-SPOT. TB, fluorescence RQ- PCR,tubereulosis （TB-Ab） protein chip and PPD methods. Results The sensitivity of four methods was 91.54% （119/ 130）,73.85%（96/130） ,63.08%（82/130） and 57.69%（75/130） respectively and the specificity of those was 89.83%（53/ 59） ,86.44%（51/59） ,67.79%（40/59） and 66.10%（39/59） ,respectively. The sensitivity of T-SPOT. TB method was sta- tistically higher than those of other three tests, respectively （P〈 0.05）. The specificity of T-SPOT. TB was significantly higher than those of TB-AB and PPD （P〈0.05） ,but there was no statistical difference between RQ-PCR and T SPOT. TB （P〈0. 05）. The positive predictive values of T-SPOT. TB, fluorescent quantitative PCR, TBAb and PPD assays were 95.2% （119/1250）,92.3% （96/104）,81.2% （82/101） and 78.9% （75/95） respectively while the negative predictive val- ues of those were 82.8% （53/64）,60% （51/85） ,45.5% （40/88） and 41.5% （39/94） ,respectively. The false-positive rates （misdiagnosis rate）of four assays were 10.2% （6/59）,13.6% （8/59）,32.2% （19/59）and 33.9%（20/59） respectively and the false-negative rates （rates of missed diagnosis） of those were 8.5% （11/130）,26.2% （34/130）,36.9% （48/130） and 42.3% （55/130） ,respectively. The negative likelihood ratios of T-SPOT. TB,fluorescent quantitative PCR,TB-Ab and PPD assays were 0.11,0.16,0.48 and 0.51 respectively, meanwhile the positive likelihood ratios of T-SPOT. TB, fluores-cent quantitative PCR,TB-Ab and PPD assays were 9.0,5.4,2.0 and 1.7, respectively. What＇s more, the diagnostic accord anee rates of the four assays were 91.0% （172/189）,77.8% （147/189） ,64.6% （122/189） and 60.3% （114/189）,respec- tively. Conclusion T-SPOT. TB test is a more sensitive and specific method and of great significance to the early diagnosis of TB,which has more clinical value in different stages of tuberculosis diagnosis.