Centre for Biotechnology, Maharshi Dayanand University, Rohtak-124001, India.
Diagn Microbiol Infect Dis. 2012 Feb;72(2):166-74. doi: 10.1016/j.diagmicrobio.2011.10.010.
Immuno-polymerase chain reaction (I-PCR) combines the versatility of enzyme-linked immunosorbent assay (ELISA) with the exponential amplification power of PCR. The present study was designed to detect antibodies to Mycobacterium tuberculosis complex-specific region of difference (RD) antigens, i.e., early secretory antigenic target-6, culture filtrate protein-10, culture filtrate protein-21, and mycobacterial protein from species tuberculosis-64, as well as antigens in pulmonary tuberculosis patients by I-PCR assay. We could detect ESAT-6 and other RD antigens up to 0.1 fg by I-PCR assay, thus resulting in 10(7) times higher sensitivity than that observed with ELISA. With paired sample analysis based on the detection of antibodies in serum and antigens in sputum of the same individual, the sensitivity of RD multi-antigen cocktail-based I-PCR assay was 72% in smear-negative cases and 91% in smear-positive cases of pulmonary tuberculosis with high specificity values. In extrapulmonary tuberculosis patients, higher sensitivity was observed by detecting cocktail of antigens by I-PCR assay as compared to sensitivity earlier observed in the same samples by ELISA.
免疫聚合酶链反应（I-PCR）将酶联免疫吸附测定（ELISA）的多功能性与 PCR 的指数扩增能力相结合。本研究旨在通过 I-PCR 检测针对结核分枝杆菌复合体特异性差异区（RD）抗原的抗体，即早期分泌抗原靶-6、培养滤液蛋白-10、培养滤液蛋白-21 和来自结核分枝杆菌-64 种的分枝杆菌蛋白，以及肺结核患者的抗原。我们可以通过 I-PCR 检测到 ESAT-6 和其他 RD 抗原，低至 0.1 fg，因此比 ELISA 观察到的灵敏度高 10 倍。通过对个体血清中抗体和痰中抗原的配对样本分析，基于 RD 多抗原鸡尾酒的 I-PCR 检测在涂片阴性的肺结核病例中的灵敏度为 72%，在涂片阳性的肺结核病例中的灵敏度为 91%，特异性值较高。与 ELISA 早期在相同样本中观察到的灵敏度相比，通过 I-PCR 检测抗原鸡尾酒，在肺外结核患者中观察到更高的灵敏度。
