Development and validation of an analytical method for the simultaneous determination of the alcohol biomarkers ethyl glucuronide, ethyl sulfate, N-acetyltaurine, and 16:0/18:1-phosphatidylethanol in human blood

Influence of Drugs and Toxins on Decomposition Dynamics: Forensic Implications

Drug and toxin-related deaths are common worldwide, making it essential to detect the postmortem concentration of various toxic substances at different stages of decomposition in a corpse. Indeed, determining the postmortem interval (PMI) and cause of death in an advanced stage of decomposed corpses has been a significant challenge in forensic investigations. Notably, the presence of drugs or toxins can have a significant impact on the microbial profile, potentially altering the succession of microbial communities and subsequent production of volatile organic compounds (VOCs), which, in turn, affect insect colonization patterns. This review aims to highlight the importance of investigating the interactions between drugs or toxins, microbial succession, VOC profiles, and insect behavior, which can provide valuable insights into forensic investigations as well as the ecological consequences of toxins occurring in decomposition. Overall, the detection of drugs and other toxins at different stages of decomposition can yield more precise forensic evidence, thereby enhancing the accuracy of PMI estimation and determination of the cause of death in decomposed remains.

Confounders of Serum Phosphatidylethanol: Role of Red Blood Cell Turnover and Cirrhosis

Purpose

Ethyl glucuronide (EtG), ethyl sulfate (EtS) and phosphatidylethanol (PEth) are considered specific direct biomarkers for detecting alcohol consumption. However, PEth, which is produced in red blood cells (RBC), varies considerably between patients for unknown reasons. We here studied various confounders of PEth elimination including fibrosis after alcohol withdrawal.

Patients and Methods

EtG, EtS and PEth together with routine laboratory and clinical parameters were studied in 100 Caucasian heavy drinkers prior and after alcohol detoxification. In addition, fibrosis stage and degree of steatosis were assessed by transient elastography (Fibroscan, Echosens, Paris).

Results

All three biomarkers were highly correlated (0.61-0.72) with initial serum alcohol levels, but only PEth correlated with daily alcohol consumption. After alcohol withdrawal, PEth significantly decreased within 6.1 days from 1708 to 810 ng/mL (half-life varied from 1.6 to 15.2 days). Both levels of serum alcohol but also EtG and EtS were higher in patients with liver cirrhosis as compared to patients without fibrosis despite comparable alcohol consumption suggesting a decreased alcohol elimination in patients with cirrhosis. PEth was also elevated in cirrhosis but not significantly. In contrast, PEth elimination rate was significantly higher in patients with enhanced RBC turnover and signs of alcohol-mediated hemolytic anemia with elevated ferritin, LDH and increased mean corpuscular volume (MCV).

Conclusion

We here demonstrate that alcohol elimination is decreased in patients with liver cirrhosis. In patients with cirrhosis, PEth levels are both affected in opposite directions by enhanced red blood cell turnover and elevated alcohol levels. Our data have important implications for the use and interpretation of PEth in the clinical setting.

Validation of a new method for the detection of Ethyl glucuronide in larvae of Lucilia sericata as a marker of ante-mortem alcohol consumption

Larvae and insects are an important and alternative biological matrix in the development anpost-mortem forensic toxicology. They are very useful when conventional matrices are not available, in particular when the loss of biological fluids, due to the decomposition of corpses or to a traumatic death, occurs. The purpose of this study is to develop and validate an analytical method in Ultra High-Performance Liquid Chromatography at High Resolution Mass Spectrometry (HPLC/HR-MS) for the research and quantification of Ethyl glucuronide (EtG) on larvae. The criteria taken into consideration for the validation are linearity, quantitation limits (LOD and LLOQ), accuracy, precision, carryover, interferences and ionization suppression/enhancement. The method was shown to be linear within the tested range, with a coefficient of determination higher than 0.99. LOD was 2 pg mg-1, while LLOQ was 5 pg mg-1. Accuracy, precision and ionization/suppression enhancement fulfilled the criteria indicated in the guidelines used for the validation. The establishment and validation of this method allowed the identification of Ethyl glucuronide on the larvae of Lucilia sericata (Calliphoridae) of a subject found death in an advanced state of decomposition.

Phospholipid metabolites of GHB as potential biomarkers in whole blood: Synthesis, analytics, and in vitro formation of homolog 16:0/18:1

Gamma-hydroxybutyric acid (GHB) is a common drug of abuse, and the detection of a consumption or administration is a longstanding research objective in clinical and forensic toxicology. However, until now, the short detection window of GHB could not be enlarged by the use of GHB metabolites. Therefore, new biomarkers for the detection of a GHB intake are needed. In analogy to phosphatidylethanols as long-time biomarkers of ethanol, phospholipids with GHB might represent a promising compound class. While the availability of reference compounds often represents a bottleneck in clinical and forensic toxicological research, two phospholipids-phosphatidyl-GHB (16:0/18:1) and its isomer phosphatidyl beta-hydroxybutyric acid (16:0/18:1)-were successfully synthesized by a new highly versatile synthetic route. Structural characterization data, together with ¹ H-, ¹³ C-, and ³¹ P-NMR and high-resolution mass spectrometry (HRMS) spectra, are reported. Subsequently, a HPLC-MS/MS method was established for the determination of both compounds (limits of detection [LOD] ≤ 2 ng/ml), and the formation of these metabolites was investigated in two in vitro experiments. The formation of phosphatidyl-GHB (16:0/18:1) was observed in an incubation experiment by converting phosphatidylcholine (16:0/18:1) and GHB with phospholipase D and in whole blood samples spiked with 50 mM GHB, respectively. Therefore, phosphatidyl-GHB (16:0/18:1) might represent a valuable new metabolite of GHB with the potential for an extension of the detection window as GHB biomarker.

Falsely low phosphatidylethanol may be associated with biomarkers of haemolytic disease

AIMS

Falsely lower or even negative phosphatidylethanol (PEth) levels may theoretically be seen in patients with haemolytic diseases, and the present study aimed to elucidate this hypothesis.

METHODS

PEth and carbohydrate-deficient transferrin (CDT) from 9893 serum and whole blood samples were included along with markers of haemolysis (i.e. haptoglobin, HbA1c, reticulocytes, LD and Hb). Cases showing discrepancy between PEth and CDT, that is, a low PEth value and a high CDT value, were considered to be possibly caused by falsely lowered PEth despite high alcohol consumption. These cases (N = 233) were compared to the control group without PEth and CDT mismatch.

RESULTS

The levels of haptoglobin were significantly lower in the cases showing low PEth and high CDT (estimate = -0.62, p = 0.002). The levels of HbA1c (estimate = -3.26, p = 0.001) and Hb (estimate = -0.507, p < 0.001) were also significantly lower in this group. These findings indicate haemolytic diseases in the low PEth/high CDT group. There were no significant differences for reticulocytes and LD concentrations between the low PEth/high CDT group and the control group.

CONCLUSIONS

These results indicate that falsely low PEth values could be associated with markers of haemolytic diseases, although more research is needed to highlight this further.

Common Laboratory Parameters Are Useful for Screening for Alcohol Use Disorder: Designing a Predictive Model Using Machine Learning

The diagnosis of alcohol use disorder (AUD) remains a difficult challenge, and some patients may not be adequately diagnosed. This study aims to identify an optimum combination of laboratory markers to detect alcohol consumption, using data science. An analytical observational study was conducted with 337 subjects (253 men and 83 women, with a mean age of 44 years (10.61 Standard Deviation (SD)). The first group included 204 participants being treated in the Addictive Behaviors Unit (ABU) from Albacete (Spain). They met the diagnostic criteria for AUD specified in the Diagnostic and Statistical Manual of mental disorders fifth edition (DSM-5). The second group included 133 blood donors (people with no risk of AUD), recruited by cross-section. All participants were also divided in two groups according to the WHO classification for risk of alcohol consumption in Spain, that is, males drinking more than 28 standard drink units (SDUs) or women drinking more than 17 SDUs. Medical history and laboratory markers were selected from our hospital's database. A correlation between alterations in laboratory markers and the amount of alcohol consumed was established. We then created three predicted models (with logistic regression, classification tree, and Bayesian network) to detect risk of alcohol consumption by using laboratory markers as predictive features. For the execution of the selection of variables and the creation and validation of predictive models, two tools were used: the scikit-learn library for Python, and the Weka application. The logistic regression model provided a maximum AUD prediction accuracy of 85.07%. Secondly, the classification tree provided a lower accuracy of 79.4%, but easier interpretation. Finally, the Naive Bayes network had an accuracy of 87.46%. The combination of several common biochemical markers and the use of data science can enhance detection of AUD, helping to prevent future medical complications derived from AUD.