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Smith CC, Stevens J, Novelli M, Maskey D, Sutherland GT. Phosphatidylethanol in post-mortem brain: Correlation with blood alcohol concentration and alcohol use disorder. Alcohol 2024; 119:17-22. [PMID: 38763230 DOI: 10.1016/j.alcohol.2024.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/15/2024] [Accepted: 05/15/2024] [Indexed: 05/21/2024]
Abstract
Phosphatidylethanol (PEth) is an alcohol derivative that has been employed as a blood-based biomarker for regular alcohol use. This study investigates the utility of phosphatidylethanol (PEth) as a biomarker for assessing alcohol consumption in post-mortem brain tissue. Using samples from the New South Wales Brain Tissue Resource Centre, we analysed PEth(16:0/18:1) levels in the cerebellum and meninges of individuals with varying histories of alcohol use, including those diagnosed with alcohol use disorder (AUD) and controls. Our findings demonstrate a significant correlation between PEth levels and blood alcohol content (BAC) at the time of death, supporting the biomarker's sensitivity to recent alcohol intake. Furthermore, this study explores the potential of PEth levels in differentiating AUD cases from controls, taking into consideration the complexities of diagnosing AUD post-mortem. The study also examined the relationship between PEth levels and liver pathology, identifying a link with the severity of liver damage. These results underscore the value of PEth as a reliable indicator of alcohol consumption and its potential contributions to post-mortem diagnostics and consequently, research into alcohol-related brain damage.
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Affiliation(s)
- Caine C Smith
- New South Wales Brain Tissue Research Centre, Charles Perkins Centre and School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Julia Stevens
- New South Wales Brain Tissue Research Centre, Charles Perkins Centre and School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Mario Novelli
- New South Wales Brain Tissue Research Centre, Charles Perkins Centre and School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Dhiraj Maskey
- New South Wales Brain Tissue Research Centre, Charles Perkins Centre and School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Greg T Sutherland
- New South Wales Brain Tissue Research Centre, Charles Perkins Centre and School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2006, Australia.
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Intérêt des dried blood spots pour stabiliser des analytes in vitro : exemple du phosphatidyléthanol 16:0/18:1. TOXICOLOGIE ANALYTIQUE ET CLINIQUE 2021. [DOI: 10.1016/j.toxac.2021.06.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Scholz C, Cabalzar J, Kraemer T, Baumgartner MR. A Comprehensive Multi-Analyte Method for Hair Analysis: Substance-Specific Quantification Ranges and Tool for Task-Oriented Data Evaluation. J Anal Toxicol 2021; 45:701-712. [PMID: 32986078 DOI: 10.1093/jat/bkaa131] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/09/2020] [Accepted: 09/17/2020] [Indexed: 12/14/2022] Open
Abstract
The aim of the present study was to quantify a large number of analytes including opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics within a single sample workup followed by a single analytical measurement. Expected drug concentrations in hair are strongly substance dependent. Therefore, three different calibration ranges were implemented: 0.5 to 600 pg/mg (group 1), 10 to 12,000 pg/mg (group 2) and 50 to 60,000 pg/mg (group 3). In order to avoid saturation effects, different strategies were applied for selected transitions including the use of parent mass ions containing one or two 13C-isotopes and detuning of the declustering potential and/or collision energy. Drugs were extracted from pulverized hair by a two-step extraction protocol and measured by liquid chromatrography--tandem mass spectrometry (LC--MS-MS) using Scheduled MRM™ Algorithm Pro. In total, 275 MRM transitions including 43 deuterated standards were measured. The method has been fully validated according to international guidelines. A MultiQuant™ software based tool for task-oriented data evaluation was established, which allows extracting selected information from the measured data sets. The matrix effects and recoveries were within the allowed ranges for the majority of the analytes. The lower limits of quantification (LLOQs) were for ∼72% of the analytes in the low-pg/mg range (0.5-5 pg/mg) and for ∼24% of the analytes between 10 and 50 pg/mg. These LLOQs considered cut-offs by the Society of Hair Testing (SoHT), if recommended. The herein established multi-analyte approach meets the specific requirements of forensic hair testing and can be used for the rapid and robust measurement of a wide range of psychoactive substances. The analyte-specific wide concentration ranges open up a wide field of applications.
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Affiliation(s)
- C Scholz
- Center for Forensic Hair Analytics, Zurich Institute of Forensic Medicine, University of Zurich, CH-8006 Zurich, Switzerland
| | - J Cabalzar
- AB Sciex Switzerland GmbH, SCIEX, CH-5401 Baden, Switzerland
| | - T Kraemer
- Department of Forensic Pharmacology and Toxicology, Zurich Institute of Forensic Medicine, University of Zurich, CH-8006 Zurich, Switzerland
| | - M R Baumgartner
- Center for Forensic Hair Analytics, Zurich Institute of Forensic Medicine, University of Zurich, CH-8006 Zurich, Switzerland
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Comments on "Evaluation and review of ways to differentiate sources of ethanol in post-mortem blood". Int J Legal Med 2021; 135:1477-1479. [PMID: 33611668 DOI: 10.1007/s00414-021-02529-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/03/2021] [Indexed: 10/22/2022]
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Luginbühl M, Young RSE, Stoeth F, Weinmann W, Blanksby SJ, Gaugler S. Variation in the Relative Isomer Abundance of Synthetic and Biologically Derived Phosphatidylethanols and Its Consequences for Reliable Quantification. J Anal Toxicol 2021; 45:76-83. [PMID: 32248226 DOI: 10.1093/jat/bkaa034] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/21/2020] [Accepted: 03/11/2020] [Indexed: 12/21/2022] Open
Abstract
Phosphatidylethanol (PEth) in human blood samples is a marker for alcohol usage. Typically, PEth is detected by reversed-phase liquid chromatography coupled with negative ion tandem mass spectrometry, investigating the fatty acyl anions released from the precursor ion upon collision-induced dissociation (CID). It has been established that in other classes of asymmetric glycerophospholipids, the unimolecular fragmentation upon CID is biased depending on the relative position (known as sn-position) of each fatty acyl chain on the glycerol backbone. As such, the use of product ions in selected-reaction-monitoring (SRM) transitions could be prone to variability if more than one regioisomer is present in either the reference materials or the sample. Here, we have investigated the regioisomeric purity of three reference materials supplied by different vendors, labeled as PEth 16:0/18:1. Using CID coupled with ozone-induced dissociation, the regioisomeric purity (% 16:0 at sn-1) was determined to be 76, 80 and 99%. The parallel investigation of the negative ion CID mass spectra of standards revealed differences in product ion ratios for both fatty acyl chain product ions and ketene neutral loss product ions. Furthermore, investigation of the product ion abundances in CID spectra of PEth within authentic blood samples appears to indicate a limited natural variation in isomer populations between samples, with the cannonical, PEth 16:0/18:1 (16:0 at sn-1) predominant in all cases. Different reference material isomer distributions led to variation in fully automated quantification of PEth in 56 authentic dried blood spot (DBS) samples when a single quantifier ion was used. Our results suggest caution in ensuring that the regioisomeric compositions of reference materials are well-matched with those of the authentic blood samples.
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Affiliation(s)
| | - Reuben S E Young
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
| | - Frederike Stoeth
- Institute of Forensic Medicine Bern, Forensic Toxicology and Chemistry, University of Bern, Bern, Switzerland
| | - Wolfgang Weinmann
- Institute of Forensic Medicine Bern, Forensic Toxicology and Chemistry, University of Bern, Bern, Switzerland
| | - Stephen J Blanksby
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, Australia
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Quantitative determination of phosphatidylethanol in dried blood spots for monitoring alcohol abstinence. Nat Protoc 2020; 16:283-308. [PMID: 33288956 DOI: 10.1038/s41596-020-00416-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022]
Abstract
Phosphatidylethanol (PEth), which is formed by enzymatic reaction between ethanol and phosphatidylcholine, is a direct marker for alcohol usage. PEth has a long elimination half-life (~5-10 d) and specimens can be sampled using minimally invasive microsampling strategies. In combination with rapid analysis procedures PEth has proved to be advantageous for the detection of abstinence over other direct (e.g., ethyl glucuronide in blood, urine or hair) and indirect (e.g., carbohydrate-deficient transferrin in serum) alcohol markers. Although PEth determination is widely applied around the world, laboratory protocols are not standardized. Here we provide general guidelines for the analysis of PEth in dried blood spots (DBSs), including reference material evaluation, synthesis of a deuterated internal standard, preparation of calibration samples (reference material in teetotaller blood), and analyte separation and detection. The protocol contains information to extract the DBSs either manually or with a fully automated autosampler. Extraction of the analytes from DBS filter paper cards is performed using an organic extraction, followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). For accurate and reliable measurement of PEth, the two most abundant analogs, PEth 16:0/18:1 and PEth 16:0/18:2, are quantified. We show data that provide guidelines on how to interpret the results for both demographic studies and forensic applications. The described protocol can be applied by experienced laboratory staff with basic LC-MS/MS knowledge and takes 2 d to perform.
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Cao M, Han Q, Zhang J, Zhang R, Wang J, Gu W, Kang W, Lian K, Ai L. An untargeted and pseudotargeted metabolomic combination approach to identify differential markers to distinguish live from dead pork meat by liquid chromatography–mass spectrometry. J Chromatogr A 2020; 1610:460553. [DOI: 10.1016/j.chroma.2019.460553] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/10/2019] [Accepted: 09/16/2019] [Indexed: 12/11/2022]
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Luginbühl M, Gaugler S, Weinmann W. Fully Automated Determination of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 in Dried Blood Spots. J Anal Toxicol 2019; 43:489-496. [DOI: 10.1093/jat/bkz035] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/17/2019] [Accepted: 04/13/2019] [Indexed: 02/04/2023] Open
Abstract
Abstract
Purpose
Direct alcohol markers are widely applied during abstinence monitoring, driving aptitude assessments and workplace drug testing. The most promising direct alcohol marker was found to be phosphatidylethanol (PEth). Compared to other markers it shows a long window of detection due to accumulation in blood. To facilitate and accelerate the determination of PEth in DBS, we developed a fully automated analysis approach.
Methods
The validated and novel online-SPE-LC-MS/MS method with automated sample preparation using a CAMAG DBS-MS 500 system reduces manual sample preparation to an absolute minimum, only requiring calibration and quality control DBS.
Results
During the validation process, the method showed a high extraction efficiency (>88%), linearity (correlation coefficient >0.9953), accuracy and precision (within ±15%) for the determination of PEth 16:0/18:1 and PEth 16:0/18:2. Within a run time of about 7 min, the two monitored analogs could be baseline separated. A method comparison in liquid whole blood of 28 authentic samples from alcohol use disorder patients showed a mean deviation of less than 2% and a correlation coefficient of >0.9759. The comparison with manual DBS extraction showed a mean deviation of less than 8% and a correlation coefficient of >0.9666.
Conclusions
The automated analysis of PEth in DBS can provide a fast and accurate solution for abstinence monitoring. In contrast to the manual extraction of PEth in DBS, no laborious sample preparation is required with this automated approach. Furthermore, the application of the internal standard by a spray module can compensate for extraction bias and matrix effects.
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Affiliation(s)
- Marc Luginbühl
- Institute of Forensic Medicine, University of Bern, Bern, Switzerland
| | | | - Wolfgang Weinmann
- Institute of Forensic Medicine, University of Bern, Bern, Switzerland
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Luginbühl M, Weinmann W, Butzke I, Pfeifer P. Monitoring of direct alcohol markers in alcohol use disorder patients during withdrawal treatment and successive rehabilitation. Drug Test Anal 2019; 11:859-869. [DOI: 10.1002/dta.2567] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/21/2018] [Accepted: 12/28/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Marc Luginbühl
- Institute of Forensic MedicineUniversity of Bern Switzerland
| | | | - Ingo Butzke
- Hospital of Psychiatry Münsingen Münsingen Switzerland
| | - Philippe Pfeifer
- Hospital of Psychiatry Münsingen Münsingen Switzerland
- University Hospital of Psychiatry BernUniversity of Bern Bern Switzerland
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