Gheesling L L, Carlone G M, Pais L B, Holder P F, Maslanka S E, Plikaytis B D, Achtman M, Densen P, Frasch C E, Käyhty H
Childhood and Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
J Clin Microbiol. 1994 Jun;32(6):1475-82. doi: 10.1128/jcm.32.6.1475-1482.1994.
A standardized enzyme-linked immunosorbent assay (ELISA) was used by 11 laboratories to measure levels of total serum antibody to Neisseria meningitidis serogroup C capsular polysaccharide in 16 unpaired pre- and postvaccination serum samples. Twelve serum samples were from adults, and four were from children aged 2, 3, 5, and 9. The between-laboratory coefficient of variation for pre- and postvaccination sera ranged from 16 to 59% and 11 to 21%, respectively. The average percent difference (absolute value) from the between-laboratory means for all prevaccination sera measured by each laboratory was 24%, whereas the average percent difference was 13% for all postvaccination sera. A postvaccination quality control serum was diluted three times to give optical densities on the high, middle, and low portions of the standard reference curve. The three dilutions were assayed by the 11 laboratories a total of 241 times and yielded an overall coefficient of variation of 20%. Antibody-binding inhibition curves showed that the standardized ELISA was specific for N. meningitidis serogroup C capsular polysaccharide antibody. Fifty percent inhibition of seven serum samples was obtained after reaction with an average concentration of 0.9 micrograms of meningococcal serogroup C polysaccharide per ml; an average of 93% inhibition was obtained with 50 micrograms of polysaccharide per ml. The acceptance and use of this standardized ELISA will reduce between-laboratory assay variability and ensure a more accurate and reproducible assessment of immunogenicity for vaccines under development.
11个实验室使用标准化酶联免疫吸附测定（ELISA）法，对16份未配对的接种疫苗前后血清样本中针对脑膜炎奈瑟菌C群荚膜多糖的总血清抗体水平进行了检测。12份血清样本来自成年人，4份来自2岁、3岁、5岁和9岁的儿童。接种疫苗前后血清的实验室间变异系数分别为16%至59%和11%至21%。每个实验室测定的所有接种疫苗前血清与实验室间均值的平均差异百分比（绝对值）为24%，而所有接种疫苗后血清的平均差异百分比为13%。将一份接种疫苗后的质量控制血清进行了三次稀释，使其光密度处于标准参考曲线的高、中、低部分。这三种稀释液由11个实验室总共检测了241次，总体变异系数为20%。抗体结合抑制曲线表明，标准化ELISA法对脑膜炎奈瑟菌C群荚膜多糖抗体具有特异性。七份血清样本在与每毫升平均浓度为0.9微克的脑膜炎奈瑟菌C群多糖反应后，获得了50%的抑制率；每毫升50微克多糖时平均获得了93%的抑制率。这种标准化ELISA法的采用和使用将减少实验室间检测的变异性，并确保对正在研发的疫苗的免疫原性进行更准确和可重复的评估。
