Mariani M, Luzzi E, Proietti D, Mancianti S, Casini D, Costantino P, van Gageldonk P, Berbers G
Laboratorio di Immunochimica e Sierologia Sperimentale, Dipartimento Immunologia, Centro Ricerche, CHIRON S.p.A., Siena, Italy.
Clin Diagn Lab Immunol. 1998 Sep;5(5):667-74. doi: 10.1128/CDLI.5.5.667-674.1998.
A competitive ELISA method is described for the measurement of total antibodies to the capsular polysaccharide of Haemophilus influenzae type b (HibCPS) in human sera. The competitive method showed an excellent correlation to the radioantigen binding assay (RABA, or Farr assay) and improved correlation of sera with low titers with respect to the more conventional noncompetitive method. Overestimation of samples in the low concentration range was no longer observed with the competitive ELISA method. The free HibCPS competition allowed us to eliminate the day-to-day background variation typical of some sera; thus, only values representing the true anti-HibCPS response were determined. The use of precoated microplates, which could be stored up to 8 months, greatly improved the speed of the procedure. An overall correlation coefficient of 0. 9660 was found when 407 serum samples with a wide variety of anti-HibCPS antibody levels were tested with the competitive ELISA and RABA. The regression line was very close to the ideal line, with a slope of 1.0045 and an intercept of -0.1996. A subset of 96 serum samples representative of all pre- and postimmunization samples was used to compare the competitive ELISA with a previously described ELISA method. The competitive method performed in two laboratories in different countries showed a better correlation with the RABA. The correlation factors were 0.9770 and 0.9816, respectively, while a factor of 0.9547 was found with the previously described noncompetitive procedure, which was better for this method than previously reported (r = 0.917). Therefore, the competitive ELISA is proposed for the assay of anti-HibCPS titers in sera from vaccinated subjects.
本文描述了一种用于检测人血清中b型流感嗜血杆菌荚膜多糖（HibCPS）总抗体的竞争性酶联免疫吸附测定（ELISA）方法。该竞争法与放射抗原结合试验（RABA，或Farr试验）显示出极佳的相关性，并且相对于更传统的非竞争法，在低滴度血清方面具有更好的相关性。使用竞争ELISA法不再观察到低浓度范围内样本的高估现象。游离的HibCPS竞争使我们能够消除某些血清中典型的日常背景变化；因此，仅测定代表真正抗HibCPS反应的值。使用可储存长达8个月的预包被微孔板，极大地提高了检测速度。当用竞争ELISA法和RABA法检测407份具有广泛抗HibCPS抗体水平的血清样本时，总体相关系数为0.9660。回归线非常接近理想线，斜率为1.0045，截距为 -0.1996。使用一组96份代表所有免疫前和免疫后样本的血清样本，将竞争ELISA法与先前描述的ELISA法进行比较。在不同国家的两个实验室进行的竞争法与RABA显示出更好的相关性。相关系数分别为0.9770和0.9816，而先前描述的非竞争法的相关系数为0.9547，该方法在此处比先前报道的情况更好（r = 0.917）。因此，建议使用竞争ELISA法检测接种疫苗受试者血清中的抗HibCPS滴度。
