The integrity of blood plasma/serum (P/S) specimens can be impacted by preanalytical handling and storage conditions that result in thawed-state exposures (> −30°C). We recently reported a simple dilute-and-shoot, intact-protein liquid chromatography/mass spectrometry (LC/MS) assay called ΔS-Cys-Albumin that quantifies cumulative exposure of P/S to thawed conditions based on the change in relative abundance of the oxidized (S-cysteinylated) proteoform of albumin (S-Cys-Albumin) in the native sample to that of an aliquot of the sample intentionally driven to its maximum oxidation state. Herein, we evaluated the effect of prestorage delay and initial storage temperature on sample integrity by applying the ΔS-Cys-Albumin assay to a set of plasma samples (n = 413) collected under a single clinical study but from 12 different collection sites. Major differences (p < 0.0001) were observed between different groups of samples with modestly inconsistent initial handling conditions (i.e., initial processing of whole blood to plasma and placement at −80°C completed in under 3 hours, 3–13 hours, and over 17 hours). ΔS-Cys-Albumin was significantly inversely correlated with delay time at 4°C before centrifugation and total delay before final storage at −80°C (p < 0.0001). Samples from two collection sites had much lower ΔS-Cys-Albumin values relative to samples from other sites, in accordance with the fact that they were stored at −20°C for an average of 7.6 months before shipment to the central repository for final storage at −80°C. Based on the rate law for S-Cys-Albumin formation in plasma ex vivo, the average time that each plasma specimen had been exposed to the equivalent of room temperature (23°C) was back calculated from the measured ΔS-Cys-Albumin values. A survey of clinical analytes in P/S whose measured concentrations are sensitive to the initial handling/storage conditions documented in this study is provided and the ramifications of the plasma integrity findings from this multisite clinical study are discussed.

中文翻译：

---

多站点收集研究中血浆解冻状态暴露时间的生化跟踪变异性。

血浆/血清 (P/S) 样本的完整性可能会受到分析前处理和储存条件的影响，这些条件会导致解冻状态暴露 (> −30°C)。我们最近报道了一种称为 ΔS-Cys-白蛋白的简单的稀释和注射、完整蛋白质液相色谱/质谱 (LC/MS) 测定法，它根据相对丰度的变化量化 P/S 在解冻条件下的累积暴露量将天然样品中白蛋白 (S-Cys-Albumin) 的氧化（S-半胱氨酰化）蛋白转化为有意驱动至其最大氧化状态的样品等分试样。在此，我们通过将 ΔS-Cys-白蛋白测定法应用于一组血浆样品 ( n = 413) 在一项临床研究下从 12 个不同的收集点收集。 在具有适度不一致的初始处理条件（即，将全血初始处理为血浆并放置在 -80°C 下，在 3 小时、3-13 小时和更长时间内完成）的不同样本组之间观察到主要差异 ( p < 0.0001) 17 小时）。ΔS-Cys-白蛋白与离心前 4°C 的延迟时间和 -80°C 最终储存前的总延迟显着负相关（p < 0.0001）。来自两个采集点的样本的 ΔS-Cys-白蛋白值相对于来自其他站点的样本要低得多，这是因为它们在运往中央储存库进行最终存储之前在 -20°C 下平均储存了 7.6 个月在-80°C。根据离体血浆中 S-Cys-白蛋白形成的速率定律，每个血浆样本暴露于相当于室温 (23°C) 的平均时间是根据测量的 ΔS-Cys-白蛋白值反算得出的. 提供了 P/S 中临床分析物的调查，其测量浓度对本研究中记录的初始处理/储存条件敏感，并讨论了该多中心临床研究的血浆完整性结果的影响。