Ossewaarde J M, de Vries A, van den Hoek J A, van Loon A M
Laboratory of Virology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
J Clin Microbiol. 1994 Jun;32(6):1419-26. doi: 10.1128/jcm.32.6.1419-1426.1994.
Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.
采用两种不同方法来防止交叉反应抗体与属反应性衣原体脂多糖（LPS）结合，以提高用于检测沙眼衣原体抗体的酶免疫测定的特异性。包被的原体用高碘酸钠处理以氧化LPS的抗原位点，或用 Triton X-100处理以提取LPS。通过使用这些新的酶免疫测定、标准酶免疫测定和全包涵体荧光（WIF）测定，检测了不同患者组和对照组血清中的沙眼衣原体抗体。来自经培养证实患有泌尿生殖系统沙眼衣原体感染患者的配对血清样本在所有三种测定中显示出相似的反应。来自鹦鹉热衣原体感染患者的配对血清样本在WIF测定和标准酶免疫测定中显示出相似的反应，而在用处理过的抗原进行的酶免疫测定中滴度显著降低，尤其是在恢复期血清样本中。对有沙眼衣原体感染症状的患者、孕妇和献血者的血清样本进行了所有三种类型的测定。在WIF测定滴度处于较低水平（IgG，1:≤256；IgA，1:≤32；IgM，1:≤16）的血清中，观察到免疫球蛋白G（IgG）、IgA和IgM滴度有80%显著降低。从这些结果我们得出结论，高碘酸钠对抗原的氧化是一种简单有效的方法，可产生特异性增强的酶免疫测定，这对诊断目的和血清流行病学研究可能有用。
