Chair of Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany.
Analyst. 2020 Mar 21;145(6):2378-2388. doi: 10.1039/c9an01880h. Epub 2020 Feb 10.
Quantitative analysis of oxylipins in blood samples is of increasing interest in clinical studies. However, storage after sampling and transport of blood might induce artificial changes in the apparent oxylipin profile due to ex vivo formation/degradation by autoxidation or enzymatic activity. In the present study we investigated the stability of free (i.e. non-esterified) and total oxylipins in EDTA-plasma and serum generated under clinical conditions assessing delays in sample processing and automated transportation: Free cytochrome P450 monooxygenase and 5-lipoxygenase (LOX) formed oxylipins as well as autoxidation products were marginally affected by storage of whole blood up to 4 h at 4 °C, while total (i.e. the sum of free and esterified) levels of these oxylipins were stable up to 24 h and following transport. Cyclooxygenase (COX) products (TxB, 12-HHT) and 12-LOX derived hydroxy-fatty acids were prone to storage and transport induced changes due to platelet activation. Total oxylipin patterns were generally more stable than the concentration of free oxylipins. In serum, coagulation induced higher levels of COX and 12-LOX products showing a high inter-individual variability. Overall, our results indicate that total EDTA-plasma oxylipins are the most stable blood oxylipin marker for clinical samples. Here, storage of blood before further processing is acceptable for a period up to 24 hours at 4 °C. However, levels of platelet derived oxylipins should be interpreted with caution regarding potential ex vivo formation.
在临床研究中，对血液样本中的氧化脂类进行定量分析越来越受到关注。然而，采样后储存和血液运输可能会由于自氧化或酶活性导致体外形成/降解，从而对明显的氧化脂类谱产生人为变化。在本研究中，我们研究了 EDTA 血浆和血清中游离（即非酯化）和总氧化脂类的稳定性，这些氧化脂类是在临床条件下评估样品处理和自动运输延迟下产生的：游离细胞色素 P450 单加氧酶和 5-脂氧合酶（LOX）形成的氧化脂类以及自氧化产物受 4°C 下全血储存长达 4 小时的影响很小，而这些氧化脂类的总水平（即游离和酯化的总和）在 24 小时内和运输后保持稳定。环加氧酶（COX）产物（TxB、12-HHT）和 12-LOX 衍生的羟脂肪酸由于血小板激活，容易受到储存和运输诱导的变化。总氧化脂类模式通常比游离氧化脂类的浓度更稳定。在血清中，凝血诱导更高水平的 COX 和 12-LOX 产物，表现出高度的个体间变异性。总的来说，我们的结果表明，总 EDTA 血浆氧化脂类是临床样本中最稳定的血液氧化脂类标志物。在此，在 4°C 下，进一步处理前血液储存长达 24 小时是可以接受的。然而，对于潜在的体外形成，血小板衍生的氧化脂类水平应谨慎解释。
