Clinical Biochemistry Department, Hospital Sant Joan de Déu, Barcelona, Spain.
CIBERER-Instituto de Salud Carlos III, Barcelona, Spain.
Fluids Barriers CNS. 2019 Nov 14;16(1):34. doi: 10.1186/s12987-019-0154-5.
Cerebrospinal fluid (CSF) metabolomic investigations are a powerful tool for studying neurometabolic diseases. We aimed to assess the effect of CSF contamination with blood on the concentrations of selected biomarkers.
CSF samples were spiked in duplicate with increasing volumes of whole blood under two conditions: (A) pooled CSF spiked with fresh whole blood and frozen to cause red blood cell (RBC) lysis; (B) pooled CSF spiked with fresh blood and centrifuged (the supernatant with no RBCs was frozen until the moment of analysis). CSF concentrations of amino acids, biogenic amines, pterins, and vitamins were analysed by HPLC coupled with tandem mass spectrometry, electrochemical and fluorescence detection.
Aspartate, glutamate, taurine, ornithine, glycine, citrulline, pyridoxal 5´-phosphate, 5-methyltetrahydrofolate, and thiamine showed higher values when RBCs were lysed when compared with those of CSF with no RBC, while arginine, 5-hydroxyindoleacetic and homovanillic acids showed lower values. When RBCs were removed from CSF, only some amino acids, thiamine and pyridoxal 5´-phosphate showed moderately higher values when compared with the non-spiked CSF sample.
CSF-targeted metabolomic analysis is feasible even when substantial RBC contamination of CSF has occurred since CSF centrifugation to remove RBC prior to freezing eliminated most of the interferences observed.
脑脊液（CSF）代谢组学研究是研究神经代谢疾病的有力工具。我们旨在评估 CSF 与血液混合对选定生物标志物浓度的影响。
将 CSF 样本在两种情况下进行双重重复加标，增加全血的体积：（A）用新鲜全血和冷冻来引起红细胞（RBC）裂解的混合 CSF 加标；（B）用新鲜血液和离心（无 RBC 的上清液在分析前冷冻）的混合 CSF 加标。通过 HPLC 与串联质谱、电化学和荧光检测分析 CSF 中氨基酸、生物胺、蝶呤和维生素的浓度。
与无 RBC 的 CSF 相比，当 RBC 裂解时，天冬氨酸、谷氨酸、牛磺酸、鸟氨酸、甘氨酸、瓜氨酸、吡哆醛 5′-磷酸、5-甲基四氢叶酸和硫胺素的浓度更高，而精氨酸、5-羟色胺和高香草酸的浓度更低。当从 CSF 中去除 RBC 时，与未加标 CSF 样本相比，只有一些氨基酸、硫胺素和吡哆醛 5′-磷酸的浓度显示出中等程度的升高。
即使 CSF 中存在大量 RBC 污染，也可以进行 CSF 靶向代谢组学分析，因为在冷冻前通过 CSF 离心去除 RBC 可以消除大多数观察到的干扰。
