目的 了解2014年驻京某部队入伍新兵结核感染情况,同时对一种新的结核潜伏感染筛查方法进行评价.方法 194名入伍新兵,行胸部X线检查、结核菌素试验(PPD)、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Rv2628进行IGRA检测.结果 PPD皮肤试验和抗体检测的阳性率分别为49.7%和15.5%.CFP10-ESAT6刺激后γ干扰素释放试验(IGRA)检测发现194名新兵中潜伏感染率为22.2%.Rv2628刺激结核潜伏感染(latent tuberculosis infection,LTBI)人群后产生IFN-γ的水平显著高于健康对照(P<0.05),其刺激PPD弱阳性组(5 mm≤皮试直径<15 mm)产生的IFN-γ值显著高于强阳性组(皮试直径≥15 mm)(P<0.05),而CFP10-ESAT6刺激后产生的IFN-γ水平在这两组间差异不显著(P>0.05).CFP10-ESAT6和Rv2628刺激后产生的IFN-γ水平在抗体阴、阳性组间无显著性差异(P>0.05).Rv2628诊断结核感染的ROC曲线下面积为0.84,约登指数为0.621,此时特异度为94.7%,敏感度为67.4%.结论 联合检测抗原Rv2628及CFP10-ESAT6特异的IFN-γ值在鉴别结核活动或潜伏感染方面具有一定潜能和价值.
Objective To investigate the Mycobacterium tuberculosis infections in 2014 among Beijing army recruits, and evaluate a new method for screening latent tuberculosis infections.Methods A total of 194 army recruits were subjected to chest X-ray examination purified protein derivative(PPD) skin test, antibody detection, and interferon gamma release assay(IGRA) by ELISA combined with recombinant protein CFP10-ESAT6 and latent infection protein Rv2628.Results The positive rates of PPD skin test and antibody test were 49.7% and 15.5%, respectively.The latent infection rate of IGRA test was 22.2% in 194 cases after CFP10-ESAT6 stimulation.After stimulation of latent tuberculosis infection(LTBI) with Rv2628, IFN-γ level was significantly higher than that in healthy control group (P<0.05).The weak positive group of TST (5 mm≤diameter<15 mm) had a significantly higher level of IFN-γ than the strong positive group(diameter≥15 mm)(P<0.05),but after stimulation with CFP10-ESAT6,IFN-γ levels were not significantly different between the two groups(P>0.05).There was no significant difference between antibody negative and positive groups after stimulation by CFP10-ESAT6 and Rv2628 (P>0.05).The area under the ROC curve of Rv2628 diagnosis of tuberculosis infection was 0.84.When Youden index was 0.621,the specificity was 94.7% and sensitivity was 67.4%.ConclusionCombined detection of antigens Rv2628 and CFP10-ESAT6 specific IFN-γ values can be potentially used for differential diagnosis of active or latent tuberculosis infections.