结核分枝杆菌重组Mtb81蛋白抗原血清学诊断价值的研究

目的研究重组Mtb81(rMtb81)蛋白的抗原性,评价其在结核病血清学诊断中的价值,寻找更有效的结核病诊断试剂。方法应用基因工程技术表达、纯化rMtb81蛋白,通过酶联免疫吸附试验(ELISA)方法检测192名健康者和210例肺结核患者血清中抗结核抗体。结果 rMtb81蛋白在大肠埃希菌细胞内以包涵体形式高效表达,表达量占菌体总蛋白的30%左右,相对分子量约80.7kD,具有良好的抗原特异性。在210例结核病患者血清中,103例菌阳患者和107例菌阴患者抗rMtb81抗体的阳性率分别为37.9%和41.1%,总的灵敏度为39.5%。在192例正常人血清中,95例PPD阴性者和97例PPD阳性者抗Mtb81抗体的阳性率分别为1.1%和6.2%。结论 rMtb81蛋白可能成为结核病血清学诊断的组合抗原之一。

Serodiagnostic value of recombinant Mtb81 protein from M. tuberculosis for tuberculosis

Objective To evaluate the value of recombinant Mtb81 （rMTB81） protein from M.tuberculosis on the serodiagnosis of tuberculosis （TB）, and to develop more effective diagnostic reagents for TB. Methods The rMTB81 protein was expressed and purified by metal chelation chromatography. The antibody IgG against M.tuberculosis rMtb81 antigen in 402 human sera were detected by ELISA. Results The rMTB81 protein existed in inclusion bodies of E. coli, and amounted to 30% of total bacterial proteins. Its molecular weight was estimated about 80.7 kilodalton. Of 210 sera from TB patients, the sensitivities of antibody detection using rMTB81 protein were 37.86% in 103 bacterium-positive TB patients and 41.12% in 107 bacterium-negative TB patients. The overall sensitivity was 39.52%. Of 192 healthy subjects, their specificities of antibody detection using rMtb81 protein were 1.05% and 6.19%, respectively. The overall specificity was 3.65%. Conclusions The rMtb81 protein might be used as one of multiple antigens in the serodiagnosis of TB.