Robertson P W, Reinbott P, Duffy Y, Binotto E, Tapsall J W
Department of Microbiology, The Prince of Wales Hospital, Randwick, NSW, Australia.
Pathology. 2001 Aug;33(3):375-8.
The sensitivity of laboratory confirmation of invasive meningococcal disease (IMD) by culture or PCR is affected by prior antibiotic treatment and decreasing use of early lumbar puncture. Serological diagnosis of IMD is not widely used because of reliance on paired serum samples. The application of single point estimations of IgM antibodies in the diagnosis of IMD was explored.
Outer membrane proteins from a mix of commonly encountered meningococcal serotypes were partially purified and used as an antigen in an enzyme immunoassay for the detection of IgM antibody. The cut-off for the assay was derived using sera from blood bank donors and the accuracy then evaluated with sera from patients with culture-confirmed IMD, other bacterial infections and culture-proven nasopharyngeal colonisation with Neisseria meningitidis.
The coefficient of variability of the assay was < 10% in negative, mid- and high-range positive sera and the specificity of the assay was at least 93%. In sera collected from 49 adult patients at various times after positive blood or CSF culture-confirmed IMD, the assay had a sensitivity of 100% in specimens collected between 5 and 18 days. At the time of isolation of meningococci from either blood or CSF, eight of 29 sera were IgM-positive, but beyond 70 days no positive results were detected. No differences were seen in the IgM responses in patients from whom different serogroups of N. meningitidis were recovered.
Serological examination by single point IgM enzyme immunoassay (EIA) offers the possibility of an expanded laboratory confirmation of IMD in adults for samples taken between 5 and 18 days after onset.
侵袭性脑膜炎球菌病（IMD）通过培养或聚合酶链反应（PCR）进行实验室确诊的敏感性受先前抗生素治疗及早期腰椎穿刺使用减少的影响。IMD的血清学诊断因依赖双份血清样本而未被广泛应用。本研究探索了IgM抗体单点估计在IMD诊断中的应用。
将常见脑膜炎球菌血清型混合物中的外膜蛋白进行部分纯化，并用作酶免疫测定中检测IgM抗体的抗原。该检测的临界值通过血库供者的血清得出，然后用培养确诊的IMD患者、其他细菌感染患者以及经培养证实的脑膜炎奈瑟菌鼻咽定植患者的血清评估其准确性。
该检测在阴性、中范围和高范围阳性血清中的变异系数<10%，检测特异性至少为93%。在49例经血或脑脊液培养确诊为IMD后的不同时间采集血清的成年患者中，该检测在发病后5至18天采集的样本中敏感性为100%。在从血液或脑脊液中分离出脑膜炎球菌时，29份血清中有8份IgM呈阳性，但70天之后未检测到阳性结果。从分离出不同血清群脑膜炎奈瑟菌的患者中观察到的IgM反应无差异。
通过单点IgM酶免疫测定（EIA）进行血清学检查为发病后5至18天采集的样本在成人中扩大IMD的实验室确诊提供了可能。
