ESAT-6/CFP-10融合蛋白的抗原性分析及其对诊断结核临床应用价值

目的 分析ESAT-6/CFP-10融合蛋白作为结核抗原的特性,并探讨以其作为抗原的酶联免疫斑点实验(ELISPOT)在结核诊断中的应用价值.方法 以ESAT-6/CFP- 10融合蛋白为刺激抗原的EIISPOT法(ESAT-6/CFP-10-ELISPOT)检测经结核特异性抗原刺激后分泌γ干扰素的效应T淋巴细胞数量方法,测定65例单纯结核病患者,16例HIV/结核双重感染患者,20例HIV感染患者,32例非结核呼吸道疾病患者,30名健康体检者外周血单个核细胞中结核菌抗原特异的T淋巴细胞的频率.结果 ESAT-6/CFP- 10-ELISPOT与结核菌素皮肤试验(TST)在所有81例结核患者中的比较,ESAT-6/CFP- 10-ELISPOT阳性率98.8％,TST阳性率为56.8％;ESAT-6/CFP-10-ELISPOT在涂阳结核组、涂阴结核组、HIV/结核双重感染组阳性率分别为100.0％、97.1％、100.0％,其敏感性远高于痰涂片检查,且各组结果差异无统计学意义；20例HIV感染组有1例阳性,非结核呼吸道疾病患者组与健康对照组均为阴性,提示ESAT-6/CFP- 10-ELISPOT方法的特异度为98.8％.结论 ESAT-6/CFP-10融合蛋白可以很好的刺激效应T淋巴细胞分泌γ干扰素,适合作为结核诊断中的特异性抗原,因而可以用于ELISPOT的检测,ESAT-6/CFP- 10-ELISPOT对结核诊断有应用价值.

Clinical application and antigenicity of ESAT-6/CFP-10 fusion protein in diagnosis of tuberculosis

OBJECTIVE To analyze the specificity of ESAT-6/CFP-10 fusion protein as an antigen of tuberculosis and explore the clinical application of ESAT-6/CFP-10 enzyme-linked immunospot(ELISPOT) assay in diagnosis of tuberculosis.METHODS ESAT-6/CFP-10-ELISPOT assay was performed for detection of IFN-γ-secreting T cells which were specific for M.tuberculosis antigens.Blood samples were from 65 patients only with tuberculosis,16 patients with co-infection of HIV and TB,32 patients with other respiratory diseases,and 30 healthy individuals.RESULTS As compared with ESAT-6/CFP-10-ELISPOT assay and TST for 81 patients with tuberculosis,the positive rate of ESAT-6/CFP-10-ELISPOT was 98.8%,and the positive rate of TST was 56.8%;the positive rates of ESAT-6/CFP-10-ELISPOT in smear positive tuberculosis group,smear negative tuberculosis group,and co-infection HIV and TB group were 100.0%,97.1% and100.0% respectively,suggesting significantly higher sensitivity than that of sputum smear test,and the differences were not statistically significant.There was one positive case in HIV infection group,both the non-tuberculosis respiratory tract disease group and the control group were negative,which indicated that the specificity of ESAT-6/CFP-10-ELISPOT was 98.8%.CONCLUSION ESAT-6/CFP-10 fusion protein excellently stimulated T cells to secret IFN-γ.It can serveas specific antigen which is suitable for the diagnosis of tuberculosis and be applied for the detection of ELISPOT.ESAT-6/CFP-10-ELISPOT is valuable for the diagnosis of tuberculosis.