Lee B W, Tan J A, Wong S C, Tan C B, Yap H K, Low P S, Chia J N, Tay J S
Department of Paediatrics, National University Hospital, Singapore.
Singapore Med J. 1994 Aug;35(4):360-3.
DNA amplification by the polymerase chain reaction (PCR) was evaluated as a means for rapid diagnosis of tuberculous meningitis (TBM).
A 240 bp region (nts 460-700) from the MPB 64 protein coding gene specific for Mycobacterium tuberculosis (TB) was selected for amplification. Nineteen clinical samples were studied. Six were obtained from patients with TBM diagnosed by culture (4/6) or by response to therapy (2/6). The remaining 13 samples were obtained from patients with febrile seizu es (8/13), aseptic meningitis (3/13) and septic meningitis (2/13), and these served as negative controls.
We detected TB DNA in all the 6 CSF specimens obtained from patients with TBM. PCR alone was sufficient to detect TB DNA in 5 of these 6 samples. However, one sample was positive only when PCR was followed by oligonucleotide hybridisation. In the 2 patients whose CSF were obtained only after commencement of TB therapy, TB cultures were negative but positive on PCR nd oligoprobe labelling. The diagnosis of TBM was confirmed based on their remarkable response to therapy. Twelve of the thirteen negative controls were TB DNA negative. There was one false positive sample, which was thought to be due to TB DNA contamination.
Taken together, our results indicate that DNA amplification using PCR, followed by oligonucleotide hybridisation offers a rapid (5 working days) means of diagnosis of TBM, provided care is taken to ensure that cross contamination of DNA samples is avoided.
评估聚合酶链反应（PCR）进行DNA扩增作为快速诊断结核性脑膜炎（TBM）的一种方法。
选择结核分枝杆菌（TB）特异的MPB 64蛋白编码基因的一个240 bp区域（核苷酸460 - 700）进行扩增。研究了19份临床样本。6份样本来自经培养（4/6）或治疗反应确诊为TBM的患者。其余13份样本来自热性惊厥患者（8/13）、无菌性脑膜炎患者（3/13）和化脓性脑膜炎患者（2/13），这些作为阴性对照。
我们在从TBM患者获得的所有6份脑脊液标本中检测到TB DNA。仅PCR就足以在这6份样本中的5份检测到TB DNA。然而，1份样本仅在PCR后进行寡核苷酸杂交时呈阳性。在2例脑脊液仅在开始抗结核治疗后采集的患者中，结核培养阴性，但PCR和寡核苷酸探针标记呈阳性。基于他们对治疗的显著反应确诊为TBM。13份阴性对照中有12份TB DNA阴性。有1份假阳性样本，认为是由于TB DNA污染所致。
总体而言，我们的结果表明，使用PCR进行DNA扩增，随后进行寡核苷酸杂交，提供了一种快速（5个工作日）诊断TBM的方法，前提是注意确保避免DNA样本的交叉污染。
