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。 Objective To investigate the levels of IFN-γ and CD4 ~ + CD25 ~ + FoxP3 ~ + regulatory T cells (Tregs) in peripheral blood of patients with tuberculosis infection and the significance of their combined detection in detecting tuberculosis activity. Methods The levels of IFN-γ and CD4 ~ + CD25 ~ + FoxP3 ~ + Treg in 44 ATB patients, 20 LTBI patients and 20 healthy controls were detected by ELISA and flow cytometry respectively. Results The strong positive rate of IFN-γ> 400 pg / ml in peripheral blood was 40.9% and 20.0% respectively in ATB group and LTBI group, and there was no significant difference in the levels of IFN-γ between ATB group and LTBI group (P> 0.05). The levels of IFN-γ in ATB group and LTBI group with IFN-γ≤400 pg / ml were significantly higher than those in control group (all P <0.01). The level of CD4 ~ + CD25 ~ + FoxP3 ~ + Treg in peripheral blood was higher in ATB group than in LTBI group and control group (all P <0.01). There was no significant difference between LTBI group and control group (P> 0.05). The area under the curve of ATB in peripheral blood CD4 ~ + CD25 ~ + FoxP3 ~ + Treg was 0.812, and the sensitivity of ATB was 72.7% with CD4 ~ + CD25 ~ + FoxP3 ~ + Treg> 9.15% Sex was 80.0%, positive predictive value was 85.0%, negative predictive value was 58.3%, and accuracy was 75.0%. Conclusion The elevated levels of IFN- and CD4 ~ + CD25 ~ + FoxP3 ~ + Treg in peripheral blood can be used as a diagnostic index for tuberculosis infection. The level of CD4 ~ + CD25 ~ + FoxP3 ~ + Treg in the diagnosis of tuberculosis activity has diagnostic value.