Dwelle T L, Dunkle L M, Blair L
J Clin Microbiol. 1987 May;25(5):856-8. doi: 10.1128/jcm.25.5.856-858.1987.
Detection of endotoxinlike activity in cerebrospinal fluid by Limulus amebocyte lysate gelation has been suggested as a useful technique for the diagnosis of gram-negative bacterial meningitis. We prospectively screened 1,503 cerebrospinal fluid specimens with a Limulus amebocyte lysate microassay. The limit of sensitivity of the assay was 0.01 ng/ml. All specimens that were positive for endotoxinlike activity were subjected to confirmatory retesting, after which 38 (86%) remained positive. Comparison with available culture results revealed that 33 of 38 specimens (86%) were culture positive; 3 of the 5 culture-negative specimens were from patients on therapy for gram-negative bacterial meningitis, and 1 was from a neonate. The overall specificity of confirmed positive tests was 99.5%, with a positive predictive value of 97.3%. There was one false-negative specimen, giving an overall sensitivity of 97.3% and a negative predictive value of 99.9%. Endotoxinlike activities of greater than or equal to 150 ng/ml correlated with present illness of less than 2 days' duration (P = 0.024), elevated cerebrospinal fluid protein (P less than 0.05), and seizures (P = 0.004); levels of greater than or equal to 3,000 ng/ml correlated with neutropenia (P = 0.032), and levels of greater than or equal to 3.2 X 10(6) ng/ml correlated with death (P = 0.001). We conclude that the Limulus amebocyte lysate microslide gelation test has prognostic value as a sensitive, specific, simple, inexpensive screening test for gram-negative bacterial meningitis.
通过鲎试剂凝胶法检测脑脊液中的类内毒素活性，已被认为是诊断革兰氏阴性菌脑膜炎的一种有用技术。我们采用鲎试剂微量分析法对1503份脑脊液标本进行了前瞻性筛查。该检测方法的灵敏度极限为0.01 ng/ml。所有类内毒素活性检测呈阳性的标本均进行了确认性复测，复测后38份（86%）仍为阳性。与现有培养结果对比发现，38份标本中有33份（86%）培养呈阳性；5份培养阴性标本中，3份来自正在接受革兰氏阴性菌脑膜炎治疗的患者，1份来自新生儿。确认阳性检测的总体特异性为99.5%，阳性预测值为97.3%。有1份假阴性标本，总体灵敏度为97.3%，阴性预测值为99.9%。类内毒素活性大于或等于150 ng/ml与病程小于2天（P = 0.024）、脑脊液蛋白升高（P < 0.05）及癫痫发作（P = 0.004）相关；大于或等于3000 ng/ml与中性粒细胞减少（P = 0.032）相关，大于或等于3.2×10⁶ ng/ml与死亡（P = 0.001）相关。我们得出结论，鲎试剂微量玻片凝胶试验作为一种用于革兰氏阴性菌脑膜炎的敏感、特异、简单且廉价的筛查试验具有预后价值。
