Institute of Legal and Traffic Medicine, University Hospital Heidelberg, Heidelberg, Germany.
Anal Bioanal Chem. 2011 Sep;401(4):1163-6. doi: 10.1007/s00216-011-5221-y. Epub 2011 Jul 9.
Phosphatidylethanol (PEth), which is formed extrahepatically by the action of phospholipase D on phosphatidylcholine in the presence of ethanol, has been suggested as a promising marker of alcohol misuse. Analysis of dried blood spots (DBS) is particularly advantageous for the determination of delicate analytes such as PEth. Therefore, measurement of PEth species (18:1/18:1, 16:0/18:1) in DBS versus whole blood was performed to ascertain whether respective results are directly comparable. Samples were obtained from subjects (n = 40) undergoing alcohol detoxification treatment. Analysis involved liquid-liquid extraction from both, DBS and whole blood (100 μL, respectively), with phosphatidylpropanol as the internal standard. Extracts were subjected to LC gradient separation using multiple reaction monitoring of deprotonated molecules. Results from measurements of corresponding DBS and whole blood specimens were compared by estimating the respective mean values and by a Bland and Altman analysis. Concentrations of PEth 18:1/18:1 ranged from 46.1 to 3,360 ng/mL in whole blood (mean, 461.7 ng/mL) and from 35.8 to 3,360 ng/mL in DBS (mean, 457.6 ng/mL); for PEth 16:0/18:1, concentrations were from 900 to 213,000 ng/mL (mean, 23,375 ng/mL) and 922-213,000 ng/mL (mean, 23,470 ng/mL) in blood and DBS, respectively. Estimated mean differences were -4.3 ng/mL for PEth 18:1/18:1 and 95.8 ng/mL for PEth 16:0/18:1. The Bland-Altman plot of both PEth species showed that the variation around the mean difference was similar all through the range of measured values and that all differences except one were within the limits of agreement. It could be shown that the determination of PEth species in DBS is as reliable as in whole blood samples. This assay may facilitate monitoring of alcohol misuse.
磷酰乙醇（PEth）是在乙醇存在的情况下，磷脂酶 D 作用于磷脂酰胆碱而在肝外形成的，已被认为是一种有前途的酒精滥用标志物。分析干血斑（DBS）对于确定 PEth 等精细分析物尤其有利。因此，对 DBS 与全血中的 PEth 种（18:1/18:1、16:0/18:1）进行了测定，以确定各自的结果是否直接可比。样本取自接受酒精解毒治疗的受试者（n=40）。分析包括从 DBS 和全血（分别为 100μL）中进行液-液提取，以磷脂丙醇作为内标。提取物采用 LC 梯度分离，通过去质子化分子的多重反应监测进行分离。通过估计各自的平均值和 Bland 和 Altman 分析来比较 DBS 和全血标本测量结果。全血中 PEth 18:1/18:1 的浓度范围为 46.1-3360ng/mL（平均值为 461.7ng/mL），DBS 中的浓度范围为 35.8-3360ng/mL（平均值为 457.6ng/mL）；对于 PEth 16:0/18:1，浓度范围为 900-213000ng/mL（平均值为 23375ng/mL）和 922-213000ng/mL（平均值为 23470ng/mL）在血液和 DBS 中。PEth 18:1/18:1 的估计平均差异为-4.3ng/mL，PEth 16:0/18:1 的估计平均差异为 95.8ng/mL。两种 PEth 种的 Bland-Altman 图显示，在整个测量值范围内，均值差异周围的变化相似，除一个差异外，所有差异均在一致性限内。结果表明，DBS 中 PEth 种的测定与全血样本一样可靠。该测定方法可能有助于监测酒精滥用。
