Laboratorio Domecq & Lafage, Hospital Alemán, Buenos Aires, Argentina.
Laboratorio Domecq & Lafage, Hospital Alemán, Buenos Aires, Argentina.
Clin Biochem. 2021 Apr;90:62-65. doi: 10.1016/j.clinbiochem.2021.01.013. Epub 2021 Feb 2.
Automated immunoassays are extensively used in routine laboratory diagnostics of endocrine disorders because of their advantages, such as high sensitivity, precision, and specificity. However, these methods are limited by the susceptibility of the immunochemical reaction to various interferences. They may present interferences related to the assay's design, for example, the endogenous presence of anti-streptavidin antibodies (ASA) in platforms that use the biotin-streptavidin interaction. To date, there have been few reports in the literature of interference from endogenous ASA. However, such antibodies would potentially lead to falsely decreased or increased results of hormones that can lead to incorrect diagnoses. We report six patients with unusual thyroid function tests, incongruent to their clinical findings. They present elevated concentrations of total T3 and T4 and TSH values within the reference range when measured at Cobas 8000® e801 module (Roche Diagnostics®). Neither patient had been taking biotin; however, all demonstrated the presence of ASA causing falsely high results on competitive assays and also falsely low results on sandwich assays. The hormone panel was also analyzed in the same samples using a different platform available in our laboratory: Cobas 6000® e601 module (Roche Diagnostics®). Nine samples were sent to an external laboratory to be measured with the chemiluminescent method: ADVIA Centaur® (Siemens® Healthcare Diagnostics). The interference seems to affect e801 module and competitive assays the most without affecting results obtained by this chemiluminescent method. This interference could potentially affect other assays performed on the same platform, such as ATPO and estradiol. Finally, laboratories should suspect the presence of interference when there is no correlation between the hormone profile and the patient's clinic. The biotin neutralization protocol demonstrated its effectiveness to eliminate ASA interference.
自动化免疫分析因其高灵敏度、精密度和特异性等优势，被广泛应用于内分泌紊乱的常规实验室诊断。然而，这些方法受到免疫化学反应对各种干扰的敏感性限制。它们可能会受到与测定设计相关的干扰，例如在使用生物素-链霉亲和素相互作用的平台中，内源性存在抗链霉亲和素抗体 (ASA)。迄今为止，文献中关于内源性 ASA 干扰的报道很少。然而，这些抗体可能导致激素的检测结果假性降低或升高，从而导致错误的诊断。我们报告了六例甲状腺功能检测异常的患者，与他们的临床发现不一致。当在 Cobas 8000® e801 模块（罗氏诊断®）上测量时，他们的总 T3、T4 和 TSH 值升高，且在参考范围内。这两个患者都没有服用生物素；然而，所有患者都表现出 ASA 的存在，导致竞争性测定结果假性升高，同时夹心测定结果假性降低。在我们实验室可用的另一个平台 Cobas 6000® e601 模块（罗氏诊断®）上，也对同一样本进行了激素检测。将 9 个样本送到外部实验室，用化学发光法测量：ADVIA Centaur®（西门子®医疗诊断）。这种干扰似乎最影响 e801 模块和竞争性测定，而不影响该化学发光法的测定结果。这种干扰可能会影响在同一平台上进行的其他测定，如 ATPO 和雌二醇。最后，当激素谱与患者的临床症状不相关时，实验室应怀疑存在干扰。生物素中和方案证明其可有效消除 ASA 干扰。
