结核感染患者外周血IFN-γ和CD4^+ CD25^+ FoxP3^+ Treg水平联合检测的意义

The significance of combined detection of peripheral-blood IFN-γ and CD4^+ CD25^+ FoxP3^+ Treg levels in patients with tuberculosis infection

目的研究结核感染患者外周血IFN-γ和CD4^+ CD25^+ FoxP3^+ 调节性T细胞(Treg)水平及其联合检测判断结核活动性的意义。方法采用ELISA和流式细胞术分别检测44例ATB患者、20例LTBI患者和20例健康者的外周血IFN-γ和CD4^+ CD25^+ FoxP3^+ Treg水平。结果以外周血IFN-γ>400 pg/ml为强阳性标准,ATB组和LTBI组强阳性率分别为40.9%和20.0%,ATB组与LTBI组外周血IFN-γ,差异均无统计学意义(P>0.05);外周血IFN-γ≤400 pg/ml的ATB组和LTBI组患者IFN-γ水平均明显高于对照组,差异有统计学意义(P均<0.01)。外周血CD4^+ CD25^+ FoxP3^+ Treg水平ATB组高于LTBI组和对照组,差异有统计学意义(P均<0.01);LTBI组和对照组比较,差异无统计学意义(P>0.05)。外周血CD4^+ CD25^+ FoxP3^+ Treg水平诊断ATB的曲线下面积为0.812,以CD4^+ CD25^+ FoxP3^+ Treg>9.15%为界值,诊断ATB的敏感性为72.7%,特异性为80.0%,阳性预测值为85.0%,阴性预测值为58.3%,准确度为75.0%。结论外周血IFN-和CD4^+ CD25^+ FoxP3^+ Treg水平升高可作为结核感染诊断指标,CD4^+ CD25^+ FoxP3^+ Treg水平在判断结核活动性方面有诊断价值。

Abstract： Objective To study the levels of peripheral - blood IFN - γ and CD4^＋ CD25 ＋ FoxP3^＋ regulatory T lymphocytes （Treg） in patients with tuberculosis infection and the significance of combined detection to judge the activity of tuberculosis in- fection. Methods The levels of peripheral - blood IFN -γ and the levels of CD4^＋ CD25 ^＋ FoxP3^＋ Treg were determined by en- zyme linked immunosorbent assay（ELISA） and flow cytometry in 44 cases of ATB group, 20 cases of LTBI group and 20 con- trols. Results To take the level of IFN - γ larger 〉 400 pg/ml as intensely positive, the intensely positive rate was 40.9% in ATB group and 20% LTBI group, which had no statistical significance on the difference of IFN -γ between ATB group and LT- BI group（ P 〉 0.05 ）. The levels of IFN -γ in 26 ATB patients and 16 LTBI patients in IFN -γ ≤400 pg/ml were all signifi- cantly higher than those of control group, and there was no statistical significance on the difference （ P 〉 0.05 ）. The levels of peripheral - blood CD4^＋ CD25^＋ FoxP3^＋ Treg in ATB group were higher than LTBI group and control group, and there was sta- tistical significance on the difference（ P 〈 0.01 ） ; and the differences between LTBI group and the control group was not statisti- cally significant（ P 〉 O. 05 ）. The area under ROC curve of peripheral - blood CD4 ＋ CD25^＋ FoxP3^＋ Treg levels was 0. 812, with that 〉 9.15% as limit, the sensitivity of ATB diagnosis was 72.7% , specificity was 80.0%, positive predictive value was 85.0% , negative predictive value was 58.3% and accuracy was 75.0%. Conclusion The increases of peripheral - blood IFN-γ and CIM^＋ CD25^＋ FoxP3^＋ Treg can be used for the diagnosis of tuberculosis infection, and CIM^＋ CD25^＋ FoxP3^＋ Treg level has diagnostic value in judging ATB.