Franco E L, Walls K W, Sulzer A J
J Clin Microbiol. 1981 May;13(5):859-64. doi: 10.1128/jcm.13.5.859-864.1981.
A reverse enzyme immunoassay (R-EIA) is described, in which polystyrene muplates are sensitized with anti-immunoglobulin M (IgM) (mu chain) antibodies and then sequentially allowed to react with patient's serum, peroxidase-labeled Toxoplasma gondii soluble antigen, and substrate. Measurement of activity of the solid-phase bound enzyme conjugate was done by colorimetric reading of the final developed color and kinetically by the initial rate of color development. This R-EIA allowed full resolution between absorbance values of a group of 36 sera which presented positive results in the Toxoplasma IgM immunofluorescence test and the remaining groups, which consisted of 39 normal individuals, 22 rheumatoid factor-positive sera, 8 Waldenstrom's macroglobulinemic sera, 3 infectious mononucleosis samples, and 6 high-titered IgG anti-T. gondii sera. No interference of rheumatoid factor IgM or inhibition by high-titered specific IgG was detected, even in the false IgM immunofluorescence-positive rheumatoid factor samples. Likewise, false-negative IgM immunofluorescence samples gave positive R-EIA even without adsorption with Staphylococcus aureus protein A. The possibility of direct tagging of the antigen with the enzyme eliminates the need for using antigen and anti-antigen conjugates as separate layers, therefore eliminating one step in the assay.
本文描述了一种反向酶免疫测定法（R-EIA），其中聚苯乙烯微孔板先用抗免疫球蛋白M（IgM）（μ链）抗体致敏，然后依次与患者血清、过氧化物酶标记的弓形虫可溶性抗原及底物反应。通过对最终显色进行比色读取以及通过显色的初始速率进行动力学测定，来测量固相结合酶结合物的活性。这种R-EIA能够完全区分一组36份在弓形虫IgM免疫荧光试验中呈阳性结果的血清与其余几组血清，其余几组包括39名正常个体、22份类风湿因子阳性血清、8份华氏巨球蛋白血症血清、3份传染性单核细胞增多症样本以及6份高滴度IgG抗弓形虫血清。即使在假IgM免疫荧光阳性的类风湿因子样本中，也未检测到类风湿因子IgM的干扰或高滴度特异性IgG的抑制作用。同样，即使未用金黄色葡萄球菌蛋白A吸附，假阴性IgM免疫荧光样本在R-EIA中也呈阳性。抗原直接用酶标记的可能性消除了将抗原和抗抗原结合物作为单独层使用的需要，因此省去了测定中的一个步骤。
