Beever K, Bradbury J, Phillips D, McLachlan S M, Pegg C, Goral A, Overbeck W, Feifel G, Smith B R
RSR Ltd., Pentwyn, Cardiff, U.K.
Clin Chem. 1989 Sep;35(9):1949-54.
These highly sensitive assays are based on the interaction between thyroid autoantibodies and 125I-labeled autoantigens. Serum samples are incubated with labeled thyroid peroxidase (TPO) or thyroglobulin (Tg) to allow the formation of antibody-labeled antigen complexes. The complexes are then precipitated by addition of solid-phase Protein A. In the presence of high concentrations of TPO antibody or Tg antibody, more than 50% of the respective labeled antigen was precipitated, whereas only 1-2% was precipitated in the absence of autoantibody. Interassay CVs were 3.2% and 5.7%, respectively, for the anti-TPO and anti-Tg assays. There was no cross-reactivity between Tg antibody and TPO antibody. Results correlated highly significantly with results from other assay systems based on antigen-coated cells or plastic supports, but the assays described here were considerably more sensitive. Scatchard analysis of the assay data provided information on the affinity and serum concentration of TPO autoantibodies (ka approximately 10(9) L/mol and concentrations up to 1 g/L) and Tg autoantibodies (ka approximately 4 x 10(10) L/mol and concentrations up to 1 g/L). Overall, these assays provide a sensitive, precise, and convenient system for measuring and investigating the properties of thyroid autoantibodies.
这些高灵敏度检测方法基于甲状腺自身抗体与125I标记的自身抗原之间的相互作用。血清样本与标记的甲状腺过氧化物酶（TPO）或甲状腺球蛋白（Tg）一起孵育，以形成抗体-标记抗原复合物。然后通过加入固相蛋白A使复合物沉淀。在高浓度的TPO抗体或Tg抗体存在下，超过50%的相应标记抗原沉淀，而在无自身抗体时只有1-2%沉淀。抗TPO和抗Tg检测的批间变异系数分别为3.2%和5.7%。Tg抗体和TPO抗体之间没有交叉反应。结果与基于抗原包被细胞或塑料支持物的其他检测系统的结果高度显著相关，但此处描述的检测方法灵敏度要高得多。对检测数据进行Scatchard分析可提供有关TPO自身抗体（亲和常数约为10(9) L/mol，浓度高达1 g/L）和Tg自身抗体（亲和常数约为4 x 10(10) L/mol，浓度高达1 g/L）的亲和力和血清浓度的信息。总体而言，这些检测方法为测量和研究甲状腺自身抗体的特性提供了一个灵敏、精确且方便的系统。
