Jain Mahim, Kennedy Adam D, Elsea Sarah H, Miller Marcus J
Dept. of Molecular and Human Genetics, Medical Genetics Laboratory, Baylor College of Medicine, Houston, TX, United States.
Metabolon Inc., Durham, NC, United States.
Clin Chim Acta. 2017 Mar;466:105-111. doi: 10.1016/j.cca.2017.01.005. Epub 2017 Jan 6.
Delaying plasma separation after phlebotomy (processing delay) can cause perturbations of numerous small molecule analytes. This poses a major challenge to the clinical application of metabolomics analyses. In this study, we further define the analyte changes that occur during processing delays and generate a model for the post hoc detection of this preanalytical error.
Using an untargeted metabolomics platform we analyzed EDTA-preserved plasma specimens harvested after processing delays lasting from minutes to days. Identified biomarkers were tested on (i) a test-set of samples exposed to either minimal (n=28) or long delays (n=40) and (ii) samples collected in a clinical setting for metabolomics analysis (n=141).
A total of 149 of 803 plasma analytes changed significantly during processing delays lasting 0-20h. Biomarkers related to erythrocyte metabolism, e.g., 5-oxoproline, lactate, and an ornithine/arginine ratio, were the strongest predictors of plasma separation delays, providing 100% diagnostic accuracy in the test set. Together these biomarkers could accurately predict processing delays >2h in a pilot study and we found evidence of sample mishandling in 4 of 141 clinically derived specimens.
Our study highlights the widespread effects of processing delays and proposes that erythrocyte metabolism creates a reproducible signal that can identify mishandled specimens in metabolomics studies.
静脉穿刺后延迟血浆分离（处理延迟）可导致多种小分子分析物发生扰动。这对代谢组学分析的临床应用构成了重大挑战。在本研究中，我们进一步明确了处理延迟期间发生的分析物变化，并生成了一个用于事后检测这种分析前误差的模型。
我们使用非靶向代谢组学平台分析了在持续数分钟至数天的处理延迟后采集的乙二胺四乙酸（EDTA）保存的血浆标本。在（i）一组暴露于最短（n = 28）或最长延迟（n = 40）的样本测试集，以及（ii）临床环境中收集用于代谢组学分析的样本（n = 141）上对鉴定出的生物标志物进行了测试。
在持续0 - 20小时的处理延迟期间，803种血浆分析物中有149种发生了显著变化。与红细胞代谢相关的生物标志物，如5 - 氧脯氨酸、乳酸以及鸟氨酸/精氨酸比值，是血浆分离延迟的最强预测指标，在测试集中提供了100%的诊断准确性。在一项初步研究中，这些生物标志物共同能够准确预测超过2小时的处理延迟，并且我们在141份临床来源的标本中有4份发现了样本处理不当的证据。
我们的研究突出了处理延迟的广泛影响，并提出红细胞代谢产生了一个可重复的信号，该信号可在代谢组学研究中识别处理不当的标本。
