Clin Chem Lab Med. 2013 Dec;51(12):2287-94. doi: 10.1515/cclm-2013-0454.
Preanalytical conditions encountered during collection, processing, and storage of biospecimens may influence laboratory results. The National Children's Study (NCS) is a planned prospective cohort study of 100,000 families to examine the influence of a wide variety of exposures on child health. In developing biospecimen collection, processing, and storage procedures for the NCS, we identified several analytes of different biochemical categories for which it was unclear to what extent deviations from NCS procedures could influence measurement results.
A pilot study was performed to examine effects of preanalytic sample handling conditions (delays in centrifugation, freezing delays, delays in separation from cells, additive delay, and tube type) on concentrations of eight different analytes. A total of 2825 measurements were made to assess 15 unique combinations of analyte and handling conditions in blood collected from 151 women of childbearing age (≥ 20 individuals per handling condition).
The majority of analytes were stable under the conditions evaluated. However, levels of plasma interleukin-6 and serum insulin were decreased in response to sample centrifugation delays of up to 5.5 h post-collection (p<0.0001). In addition, delays in freezing centrifuged plasma samples (comparing 24, 48 and 72 h to immediate freezing) resulted in increased levels of adrenocorticotropic hormone (p=0.0014).
Determining stability of proposed analytes in response to preanalytical conditions and handling helps to ensure high-quality specimens for study now and in the future. The results inform development of procedures, plans for measurement of analytes, and interpretation of laboratory results.
生物标本在采集、处理和储存过程中的分析前条件可能会影响实验室结果。国家儿童研究（NCS）是一项计划中的前瞻性队列研究，涉及 10 万个家庭，旨在研究各种暴露因素对儿童健康的影响。在为 NCS 制定生物标本采集、处理和储存程序时，我们确定了一些不同生化类别的分析物，对于这些分析物，我们不清楚偏离 NCS 程序会在多大程度上影响测量结果。
进行了一项试点研究，以检查分析前样本处理条件（离心延迟、冷冻延迟、与细胞分离延迟、添加剂延迟和管类型）对 8 种不同分析物浓度的影响。共进行了 2825 次测量，以评估从 151 名育龄妇女（每个处理条件≥20 人）采集的血液中 15 种不同分析物和处理条件的 15 种独特组合。
在评估的条件下，大多数分析物是稳定的。然而，血浆白细胞介素-6 和血清胰岛素的水平在采集后长达 5.5 小时的离心延迟时降低（p<0.0001）。此外，冷冻离心后的血浆样本（比较 24、48 和 72 小时与立即冷冻）延迟导致促肾上腺皮质激素水平升高（p=0.0014）。
确定拟议分析物对分析前条件和处理的稳定性有助于确保现在和将来研究的高质量标本。结果为程序的制定、分析物测量计划以及实验室结果的解释提供了信息。
