The Hormone Laboratory, Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.
Scand J Clin Lab Invest. 2021 Apr;81(2):92-103. doi: 10.1080/00365513.2020.1858493. Epub 2021 Jan 27.
All immunological methods are vulnerable to different kinds of interference. The purpose of this work was to study the cause and frequency of method-dependent interference in the Roche thyroid immunoassays. Serum samples with discordant thyroid function tests (TFT) were selected from samples sent to the Hormone Laboratory, Oslo University Hospital from June 2013 to September 2018. We identified 93 patients with discordant pathological TFT when analysed with the Roche methods and normal results when analysed with alternative methods. 42 of these samples were sent to Roche Diagnostics (Germany) for investigation of the interfering substance. Roche found interference to be caused by the presence of endogenous anti-streptavidin antibodies (ASA) (34 of 42 patients), ruthenium or the idiotype of the ruthenium labelled antibody (3 of 42 patients) and mouse antigens (1 of 42 patients). Method-dependent interference was estimated to affect 0.37% of the patients investigated in our laboratory. Interference due to the presence of endogenous ASA were further explored in other (non-thyroid) immunoassays by comparing analyte levels before and after pre-adsorption of the patients' sera with streptavidin-coated paramagnetic beads. An underestimation of hormone levels was observed in sandwich immunoassays, while an overestimation was found in competitive assays. Method-dependent interference in Roche thyroid immunoassays is caused mainly by ASA and is not a very rare phenomenon. Misleading results may lead to misdiagnosis and inappropriate medical treatment. The supplier of the assay should be alerted when the available alternative methodology reveals method-dependent errors.
所有免疫学方法都容易受到各种干扰。本研究旨在探讨罗氏甲状腺免疫分析中与方法相关的干扰的原因和频率。从 2013 年 6 月至 2018 年 9 月期间，我们从送到奥斯陆大学医院激素实验室的样本中选择了甲状腺功能检测（TFT）结果不一致的血清样本。当使用罗氏方法分析时，我们发现 93 例患者的 TFT 结果存在病理差异，但当使用其他方法分析时，结果则是正常的。其中 42 个样本被送到罗氏诊断公司（德国）以调查干扰物质。罗氏发现干扰是由内源性抗生物素蛋白抗体（ASA）的存在引起的（42 例患者中的 34 例）、钌或标记抗体的独特型（42 例患者中的 3 例）以及鼠抗原（42 例患者中的 1 例）。据估计，在我们的实验室中，约有 0.37%的受调查患者受到方法相关干扰的影响。我们通过比较患者血清与链霉亲和素包被的超顺磁珠预吸附前后分析物水平，进一步研究了其他（非甲状腺）免疫分析中由于内源性 ASA 存在引起的方法相关干扰。在夹心免疫测定中观察到激素水平的低估，而在竞争测定中则发现了高估。罗氏甲状腺免疫分析中的方法相关干扰主要由 ASA 引起，而且不是一种非常罕见的现象。误导性的结果可能导致误诊和不适当的治疗。当现有的替代方法学揭示与方法相关的错误时，应向检测试剂盒供应商发出警报。
