Comprehensive Assessment of M-Proteins Using Nanobody Enrichment Coupled to MALDI-TOF Mass Spectrometry
Comprehensive Assessment of M-Proteins Using Nanobody Enrichment Coupled to MALDI-TOF Mass Spectrometry
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DOI：
10.1373/clinchem.2015.253740
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发表时间：
2016-10-01
影响因子：
9.3
通讯作者：
Murray, David L.
中科院分区：
文献类型：
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作者：
Mills, John R.;Kohlhagen, Mindy C.;Murray, David L.
背景：血清和尿液蛋白的电泳分离在诊断和监测浆细胞疾病中发挥着核心作用。尽管分辨率和分析灵敏度有限，而且需要辅助方法，但蛋白质凝胶电泳和免疫固定电泳 (IFE) 仍然是一线测试。方法：我们开发了一种基于 MALDI 质谱的检测方法，该方法操作简单、可自动化、分析灵敏，适用于分析临床上遇到的各种单克隆蛋白（M 蛋白）。这种测定方法称为 MASS-FIX，利用不同 Ig 同种型的独特分子质量特征与纳米抗体免疫富集相结合，生成信息丰富的质谱，从中可以对 M 蛋白进行鉴定、同种型和定量。将 MASS-FIX 的性能与当前基于凝胶的电泳检测进行了比较。结果：MASS-FIX 检测到了可通过尿液或血清蛋白电泳检测到的所有 M 蛋白。在连续稀释研究中，MASS-FIX 的分析灵敏度比 IFE 更高。对于患者样本，MASS-FIX 为 98% 的血清 M 蛋白 (n = 152) 和 95% 的尿液 M 蛋白 (n = 55) 提供了相同的主要同种型信息。 MASS-FIX 准确定量 M 蛋白
BACKGROUND: Electrophoretic separation of serum and urine proteins has played a central role in diagnosing and monitoring plasma cell disorders. Despite limitations in resolution and analytical sensitivity, plus the necessity for adjunct methods, protein gel electrophoresis and immunofixation electrophoresis (IFE) remain front-line tests.METHODS: We developed a MALDI mass spectrometry-based assay that was simple to perform, automatable, analytically sensitive, and applicable to analyzing the wide variety of monoclonal proteins (M-proteins) encountered clinically. This assay, called MASS-FIX, used the unique molecular mass signatures of the different Ig isotypes in combination with nanobody immunoenrichment to generate information-rich mass spectra from which M-proteins could be identified, isotyped, and quantified. The performance of MASS-FIX was compared to current gel-based electrophoresis assays.RESULTS: MASS-FIX detected all M-proteins that were detectable by urine or serum protein electrophoresis. In serial dilution studies, MASS-FIX was more analytically sensitive than IFE. For patient samples, MASS-FIX provided the same primary isotype information for 98% of serum M-proteins (n = 152) and 95% of urine M-proteins (n = 55). MASS-FIX accurately quantified M-protein to