ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States.
ARUP Institute of Clinical & Experimental Pathology, Salt Lake City, UT, United States; Department of Pathology, University of Utah, Salt Lake City, UT, United States.
Prostaglandins Leukot Essent Fatty Acids. 2020 Dec;163:102211. doi: 10.1016/j.plefa.2020.102211. Epub 2020 Nov 19.
Long-chain fatty acids (LCFAs), including omega-3 and omega-6 fatty acids, play essential roles in health maintenance and outcomes. Insufficient intake or the inability to absorb LCFAs from the diet can cause a number of health problems. Evaluation of fatty acid profiles in plasma, serum or red blood cells (RBCs) is routinely used to monitor patients at risk of developing deficiency. Quantitation of LCFAs in RBCs offers advantages over serum/plasma due to low intra-individual variability. Fatty acid composition in RBCs also reflects long-term dietary intake, providing additional information about the patient's nutritional status. However, the literature does not currently address the impact of pre-analytical factors (conditions of RBC collection, sample handling and short-term storage) on LCFA measurements. This study evaluated the effect of several anticoagulants, interferents, different storage conditions and fasting status on quantitation of the twenty-one most abundant LCFAs in RBCs by gas chromatography negative chemical ionization-mass spectrometry (GCNCI-MS). LCFA results were assessed quantitatively (nmol/mL) or as a percent of total. Most common tube types (containing citrate, sodium heparin or EDTA) were all appropriate for blood collection. Whole blood and lysed RBCs were stable at least 24 h at room temperature and up to 7 days refrigerated. Lysed RBCs were also stable for up to three freeze/thaw cycles. The presence of icterus or lipemia did not affect results. LCFAs concentrations in RBCs did not change ~4 h after high-fat intake when the lipid concentration in circulation reaches a peak, while plasma levels of most fatty acids increased up to 40% in response. In summary, RBCs are a reliable sample type for LCFA quantitation in the clinical laboratory. In contrast to plasma or serum, RBCs isolated from non-fasting, hemolyzed or lipemic whole blood specimens are all acceptable for testing. Therefore, RBCs might be a preferable sample type for evaluation of nutritional status of young pediatric patients and in patients with conditions associated with hemolytic anemia or hyperlipidemia.
长链脂肪酸（LCFAs），包括 omega-3 和 omega-6 脂肪酸，在维持健康和改善健康结果方面发挥着重要作用。从饮食中摄入不足或无法吸收 LCFAs，可能会导致许多健康问题。评估血浆、血清或红细胞（RBC）中的脂肪酸谱，通常用于监测有发生缺乏风险的患者。由于个体内变异较小，因此 RBC 中的 LCFAs 定量分析优于血清/血浆。RBC 中的脂肪酸组成也反映了长期的饮食摄入，为患者的营养状况提供了更多信息。然而，目前文献并未探讨分析前因素（RBC 采集条件、样本处理和短期储存）对 LCFA 测量的影响。本研究通过气相色谱负化学电离-质谱法（GCNCI-MS）评估了几种抗凝剂、干扰物、不同储存条件和禁食状态对 RBC 中 21 种最丰富的 LCFAs 定量的影响。LCFA 结果以纳摩尔/毫升（nmol/mL）或总百分比的形式进行定量评估。最常见的管类型（含有柠檬酸盐、肝素钠或 EDTA）均适合血液采集。全血和溶血 RBC 在室温下至少稳定 24 小时，冷藏条件下可稳定 7 天。溶血 RBC 也可稳定三个冻融循环。黄疸或脂血对结果没有影响。当循环中脂质浓度达到峰值时，高脂饮食后 4 小时内 RBC 中的 LCFAs 浓度不会改变，而大多数脂肪酸的血浆水平会增加 40%。总之，RBC 是临床实验室中 LCFA 定量的可靠样本类型。与血浆或血清不同，来自非禁食、溶血或脂血的全血标本分离的 RBC 均可用于检测。因此，RBC 可能是评价年轻儿科患者营养状况和伴有溶血性贫血或高脂血症患者营养状况的首选样本类型。
