Piran U, Riordan W J, Silbert D R
Ciba-Corning Diagnostics Corp., E. Walpole, MA 02032.
J Immunol Methods. 1990 Oct 19;133(2):207-14. doi: 10.1016/0022-1759(90)90361-x.
We examined the effects of hapten heterology on triiodothyronine (T3) and thyroxine (T4) immunoassays configured with protein-conjugated diiodothyronine (T2), T3 or T4, using acridinium ester (AE) as a chemiluminescent label and paramagnetic particles (PMP) as a solid phase. Assays constructed with hapten-heterologous combinations, such as immobilized anti-T4 plus labeled T3 or immunobolized anti-T3 plus labeled T2, were superior to the homologous ones in their potential for attaining higher sensitivity. This was manifested in a shift of the displacement curves to lower analyte concentrations, accompanied by unexpectedly high bound-tracer/total-tracer (B/T) ratios. This effect of hapten heterology was apparent with the use of either monoclonal or polyclonal antibodies and did not depend upon which component (antibody or protein conjugated hormone) was immobilized on the solid phase. In contrast, heterologous displacement curves with unconjugated hormone (125I-labeled) or with a labeled Fab fragment exhibited both a shift to lower analyte concentration and the expected decrease of B/T ratios. These results can be explained by the existence of positive binding cooperativity in the interaction between antibodies and haptenated proteins. Assay specificity was not adversely affected by hapten heterology when utilizing monoclonal antibodies, and hormone levels measured in serum samples correlated well with values obtained in homologous immunoassays.
我们研究了半抗原异源性对用蛋白质偶联二碘甲状腺原氨酸（T2）、三碘甲状腺原氨酸（T3）或甲状腺素（T4）构建的三碘甲状腺原氨酸（T3）和甲状腺素（T4）免疫分析的影响，使用吖啶酯（AE）作为化学发光标记物，顺磁性颗粒（PMP）作为固相。用半抗原 - 异源组合构建的分析方法，如固定化抗 - T4加标记T3或免疫固定化抗 - T3加标记T2，在获得更高灵敏度的潜力方面优于同源分析方法。这表现为置换曲线向更低分析物浓度的偏移，同时伴有意外高的结合示踪剂/总示踪剂（B/T）比率。半抗原异源性的这种效应在使用单克隆抗体或多克隆抗体时都很明显，并且不取决于固相上固定的是哪个组分（抗体或蛋白质偶联激素）。相比之下，未偶联激素（125I标记）或标记Fab片段的异源置换曲线既表现出向更低分析物浓度的偏移，又表现出预期的B/T比率降低。这些结果可以通过抗体与半抗原化蛋白质之间相互作用中存在正结合协同性来解释。当使用单克隆抗体时，分析特异性不会受到半抗原异源性的不利影响，并且血清样品中测量的激素水平与同源免疫分析中获得的值相关性良好。
