Saunders N B, Shoemaker D R, Brandt B L, Zollinger W D
Department of Bacterial Diseases, Walter Reed Army Institute of Research, Washington, D.C. 20307-5100, USA.
J Clin Microbiol. 1997 Dec;35(12):3215-9. doi: 10.1128/jcm.35.12.3215-3219.1997.
A significant problem in efficacy trials of meningococcal vaccines has been accurate identification of all cases of meningococcal disease that occur in study populations. The accuracy of case determination would be improved by utilizing methods which confirm or disprove suspicious cases of meningococcal disease that are culture negative. A collection of serum and cerebrospinal fluid (CSF) samples from a meningococcal vaccine field trial performed in Iquique, Chile, were utilized to assess the status of patients for whom cultures, Gram stains, and clinical evaluations for meningococcal disease were available. Nested PCRs (nPCRs) for amplification of Neisseria meningitidis DNA in CSF samples and enzyme-linked immunosorbent assays (ELISAs) for quantification of serum immunoglobulin G antibodies specific for N. meningitidis were used in combination to confirm or eliminate cases classified by physicians as suspicious for meningococcal disease. Samples from 12 of 79 patients suspected of having meningococcal meningitis tested positive by both methods; specimens from 61 of the 79 were negative by both methods; and samples from 6 patients yielded ambiguous results, and these cases remained unconfirmed. Direct sequence analysis of amplified DNA from patients suspected of having meningococcal disease confirmed that 2 of the 12 newly confirmed cases were not attributable to the typical epidemic strain (B:15:P1.[7],3) while the others were due to the epidemic strain. A combination of nPCR and ELISA reduced the number of suspicious cases in this study from 79 to 6, thereby improving the potential for assessment of vaccine efficacy. Molecular identification by nPCR in conjunction with immunological assessment of patient response could be considered diagnostic of disease in future testing of meningococcal vaccines to improve efficacy analyses.
在脑膜炎球菌疫苗效力试验中，一个重大问题是准确识别研究人群中发生的所有脑膜炎球菌病病例。通过采用能够证实或排除培养结果为阴性的可疑脑膜炎球菌病病例的方法，可以提高病例判定的准确性。在智利伊基克进行的一项脑膜炎球菌疫苗现场试验中收集的血清和脑脊液（CSF）样本，被用于评估那些已有脑膜炎球菌病培养、革兰氏染色及临床评估结果的患者的状况。联合使用用于扩增脑脊液样本中脑膜炎奈瑟菌DNA的巢式聚合酶链反应（nPCR）和用于定量血清中脑膜炎奈瑟菌特异性免疫球蛋白G抗体的酶联免疫吸附测定（ELISA），以确认或排除医生判定为可疑的脑膜炎球菌病病例。79名疑似患有脑膜炎球菌性脑膜炎的患者中，有12名患者的样本经两种方法检测均呈阳性；79名患者中有61名患者的样本经两种方法检测均为阴性；6名患者的样本结果不明确，这些病例仍未得到确认。对疑似患有脑膜炎球菌病患者的扩增DNA进行直接序列分析证实，12例新确诊病例中有2例并非由典型流行菌株（B:15:P1.[7],3）引起，而其他病例则由该流行菌株引起。在本研究中，nPCR和ELISA联用将可疑病例数从79例减少至6例，从而提高了评估疫苗效力的可能性。在未来脑膜炎球菌疫苗试验中，可以考虑将通过nPCR进行的分子鉴定与患者反应的免疫学评估相结合来诊断疾病，以改进效力分析。
