BACKGROUND Daratumumab (DARA) is a fully human anti-CD38 IgG1-κ monoclonal antibody drug used in the treatment of multiple myeloma (MM). While serum protein electrophoresis (SPEP) is an important assay for diagnosis and monitoring of patients with MM, DARA can appear in the γ-region as a single band and interfere with the interpretation of SPEP results. An approach to detect the interference is measuring the quantity of DARA in serum samples and assessing its impact on SPEP results. Immunoassays based on label-free technologies, i.e. label-free immunoassays (LFIA's), can achieve real-time immunometric measurement without attaching a reporter molecule (enzyme, fluorophore, etc.) to the immunocomplex. The recorded time course of the immunocomplex formation allows for quantitation on initial binding rate, which facilitates rapid measurement within a few minutes. Based on the thin-film interferometry (TFI) technology, a rapid LFIA was established for the quantitation of DARA in serum samples. METHODS The TFI-based LFIA for DARA was validated for imprecision (CV), accuracy, limit of quantitation (LOQ), and analytical measurement range (AMR). Interference to the LFIA was evaluated using a group of protein samples, as well as hemolytic, lipemic, and icteric clinical samples. RESULTS The precision of the TFI-based LFIA's for DARA ranged from 6.5% to 10.7% (within-run CV), and 7.4% to 11.6% (between-run CV), with a bias of -2.1% to 10.1%. The LOQ was 10 μg/ml (n = 4, CV 9.8%), with an AMR ranging from the LOQ to 1000 μg/ml. The LFIA was used to measure 37 patient samples submitted for SPEP testing. The LFIA results were 100% consistent with the history of DARA use as documented in the medical record. CONCLUSIONS The TFI-based LFIA was successful at accurately identifying DARA in serum samples and can be used to identify DARA interference in SPEP testing. This work demonstrates the applicability of label-free technologies, particularly the TFI technology, to clinical diagnostic needs. Given the simplicity and the speed of the testing process, the TFI technology provides a unique testing approach for the measurement of proteins in clinical samples.

中文翻译：

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一种基于薄膜干涉术的无标记免疫测定法，用于检测血清蛋白电泳中的daratumumab干扰。

背景技术Daratumumab（DARA）是用于治疗多发性骨髓瘤（MM）的完全人类抗CD38IgG1-κ单克隆抗体药物。尽管血清蛋白电泳（SPEP）是诊断和监测MM患者的重要方法，但DARA可能在γ区以单条带出现，并干扰SPEP结果的解释。一种检测干扰的方法是测量血清样品中DARA的量，并评估其对SPEP结果的影响。基于无标记技术的免疫测定，即无标记免疫测定（LFIA），可以实现实时免疫测定，而无需将报告分子（酶，荧光团等）附着到免疫复合物上。所记录的免疫复合物形成的时间过程允许对初始结合率进行定量，这有助于在几分钟之内进行快速测量。基于薄膜干涉仪（TFI）技术，建立了快速LFIA定量分析血清样品中DARA的方法。方法对基于TFI的DARA LFIA进行不精确度（CV），准确性，定量限（LOQ）和分析测量范围（AMR）的验证。使用一组蛋白质样品以及溶血，脂血和黄疸型临床样品评估对LFIA的干扰。结果基于TFI的LFIA的DARA精度范围为6.5％至10.7％（运行内CV）和7.4％至11.6％（运行间CV），偏差为-2.1％至10.1％。LOQ为10μg/ ml（n = 4，CV为9.8％），AMR为LOQ至1000μg/ ml。LFIA用于测量提交给SPEP测试的37个患者样品。LFIA结果与病历中记载的DARA使用历史一致100％。结论基于TFI的LFIA成功地准确鉴定了血清样品中的DARA，可用于鉴定SPEP测试中的DARA干扰。这项工作证明了无标签技术（尤其是TFI技术）对临床诊断需求的适用性。鉴于测试过程的简便性和速度，TFI技术为临床样品中蛋白质的测量提供了独特的测试方法。特别是TFI技术，以满足临床诊断需求。鉴于测试过程的简便性和速度，TFI技术为临床样品中蛋白质的测量提供了独特的测试方法。特别是TFI技术，以满足临床诊断需求。鉴于测试过程的简便性和速度，TFI技术为临床样品中蛋白质的测量提供了独特的测试方法。