Rv1813c在结核分枝杆菌潜伏感染诊断中的价值

The Potential of Rv1813c in the Diagnosis of Mycobacterium Tuberculosis Latent Infection

目的研究重组结核分枝杆菌潜伏感染蛋白Rv1813c在诊断结核分枝杆菌潜伏感染方面的价值。方法 20例结核潜伏感染者和79例健康志愿者均行胸部X线检查、PPD皮肤试验、结核抗体检测,同时应用ELISA联合重组融合蛋白CFP10-ESAT6和潜伏感染蛋白Rv1813c进行IGRA检测。结果所有受试者中,PPD皮肤试验和抗体检测的阳性率分别为50%和28%。Rv1813c刺激潜伏感染者后产生IFN-γ的水平显著高于健康对照(P<0.05),其刺激PPD强阳性组(皮试直径≥15mm)产生的IFN-γ值低于弱阳性组(5mm≤皮试直径<15mm),但无统计学意义,而CFP10-ESAT6刺激PPD强阳性组后产生的IFN-γ值高于弱阳性组(P<0.05)。CFP10-ESAT6和Rv1813c刺激抗体阴性及阳性组后产生的IFN-γ水平没有显著性差异(P>0.05)。Rv1813c诊断结核感染的ROC曲线下面积为0.834,特异性80%时,灵敏度为85%;特异性为90%时,灵敏度为45%。结论同时检测Rv1813c及CFP10-ESAT6抗原特异的IFN-γ值有可能筛选出潜伏感染者中的活动感染人群,对于结核分枝杆菌潜伏感染诊断有重要的应用价值。

Objective To study the value of recombinant Mycobacterium tuberculosis latent infection related protein Rv1813c in the diagnosis of latent infection of Mycobacterium tuberculosis. Methods 20 LTBI subjects and 79 healthy controls were given chest X-ray examination, PPD skin test, antibody detection, and IGRAs by ELISA with recombinant protein CFP10-ESAT6 and latent infection protein Rv1813c. Results In all the subjects, the positive rates of PPD skin test and antibody test were 50% and 28% respectively. After stimulation with Rv1813c, IFN-γ level produced in LTBI was significantly higher than that in healthy controls （P 〈 0.05 ）, the strong positive group （diameter≥ 15 mm） was lower than that of the weak positive group of TST （5mm ≤ diameter 〈 15mm） though the difference was not statistically significant. After stimulation with CFP10-ESAT6, the IFN-γ level in the strong positive group was higher than the weak positive group （ P 〈 0.05 ）. There was no significant difference between antibody negative and positive groups after stimulation by CFP10-ESAT6 and Rv1813c （ P 〉 0.05 ）. The area under the ROC curve of tuberculosis infection diagnosis was 0. 834. While specificity was 80%, sensitivity was 85%. And while specificity was 90%, sensitivity was 45%. Conclusion Combined detection of Rv1813c and CFP10-ESAT6 specific IFN-γ values is helpful to screen the high risk population of latent infection, which has important application value for diagnosis of LTBI.