Alcohol state markers- facility and utility for clinical management of alcohol use disorders: study from a tertiary care centre in South India

Background: Alcoholism is broadly any drinking of alcohol resulting in significant psychological and physiological health problems. As alcoholism is not a recognized diagnostic entity the detection and monitoring of the clinical manifestations of alcoholism is of great importance in the alcohol use disorders (AUD) treatment. Hence, the use of alcohol biomarkers plays a vital role in the diagnosis, treatment and prognosis of AUDs.Methods: This study aimed to understand the utility of state markers in alcohol related distress, both for diagnosis and prognosis in a tertiary care centre. The relative number and the frequency of the alcohol biomarker tests such as AST (aspartate aminotransferase), ALT (alanine aminotransferase), MCV (mean corpuscular volume) and GGT (gamma-glutamyl transferase) investigated in the hospital departments (32 departments) were collected. Test requests and results in January to March on five consecutive years from 2016 to 2020 were analyzed, by comparing psychiatry department with all other departments and AUD with non-AUD cases.Results: The study findings revealed that, the tests AST, ALT and MCV were well utilized for the AUD treatment procedure in the tertiary care centre, irrespective of the department the patient got admitted. Since GGT was the least preferred test, the figures of GGT could not be analysed because of the exceptionally low number.Conclusions: The utility of the commonly available alcohol biomarker tests is especially useful for the clinical management of AUD patients and these are well utilized in an appreciable manner in the study centre. Development of more accurate, specific, and sensitive panel of biomarker tests may further motivate clinicians to better monitor individuals who suffer from alcoholism.

Measurement of the alcohol biomarker phosphatidylethanol (PEth) in dried blood spots and venous blood—importance of inhibition of post-sampling formation from ethanol

Phosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption by action of the enzyme phospholipase D (PLD). PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. However, in blood specimens containing ethanol, formation of PEth may continue after sampling leading to falsely elevated concentrations. This study evaluated the use of dried blood spot (DBS) and microsampling specimens to avoid post-sampling formation of PEth. Filter paper cards and three commercial devices for volumetric microsampling of finger-pricked blood were assessed, using PEth-negative and PEth-positive whole blood fortified with 2 g/L ethanol. PEth (16:0/18:1) was measured by LC–MS/MS. Post-sampling formation of PEth occurred in wet blood and in the volumetric devices, but not filter paper cards, when stored at room temperature for 48 h. Addition of an inhibitor of PLD, sodium metavanadate (NaVO3), eliminated post-sampling formation during storage and drying. In conclusion, the present study confirmed previous observations that PEth can be formed in blood samples after collection, if the specimen contains ethanol. The results further demonstrated that post-sampling formation of PEth from ethanol also occurred with commercial devices for volumetric dried blood microsampling. In order for a PEth result not to be questioned, it is recommended to use a PLD inhibitor, whether venous blood is collected in a vacutainer tube or finger-pricked blood is obtained using devices for dried blood microsampling. Graphical abstract

Performance of PEth Compared With Other Alcohol Biomarkers in Subjects Presenting For Occupational and Pre-Employment Medical Examination

Aims To compare the performance of short- and long-term alcohol biomarkers for the evaluation of alcohol drinking in employment-related health controls. Methods The 519 blood samples originated from 509 patients (80% men) presenting at occupational health units and medical centers at employment agencies for the evaluation of risky drinking. The laboratory investigation comprised the measurement of phosphatidylethanol (PEth 16:0/18:1), carbohydrate-deficient transferrin (CDT; % disialotransferrin), gamma-glutamyl transferase (GGT), mean corpuscular volume (MCV), ethanol and ethyl glucuronide (EtG). Results Many samples tested positive for acute (57%) and chronic (69%) alcohol biomarkers. PEth was the single most positive biomarker (64%; cut-off 0.05 μmol/l or 35 μg/l) and the only positive chronic biomarker in 100 cases. The highest PEth concentrations were seen in samples positive for all chronic biomarkers, followed by those also being CDT positive (cut-off 2.0%). All 126 CDT-positive samples were positive for PEth using the lower reporting limit (≥0.05 μmol/l) and for 114 cases (90%) also using the higher limit (≥0.30 μmol/l or 210 μg/l). In the CDT-positive cases, the PEth median concentration was 1.71 μmol/l, compared with 0.45 μmol/l for the CDT-negative cases (P < 0.0001). PEth and CDT values were correlated significantly (r = 0.63, P < 0.0001). Among the EtG-positive cases (≥1.0 ng/ml), 95% were also PEth positive, and all ethanol-positive cases (≥0.10 g/l) were also PEth positive. Conclusions For optimal detection of drinking habits, using a combination of short- and long-term alcohol biomarkers provided best information. PEth was the single most positive alcohol biomarker, whereas GGT and MCV offered little additional value over PEth and CDT.

Validation and characterisation of a DNA methylation alcohol biomarker across the life course

Background Recently, an alcohol predictor was developed using DNA methylation at 144 CpG sites (DNAm-Alc) as a biomarker for improved clinical or epidemiologic assessment of alcohol-related ill health. We validate the performance and characterise the drivers of this DNAm-Alc for the first time in independent populations. Results In N = 1049 parents from the Avon Longitudinal Study of Parents and Children (ALSPAC) Accessible Resource for Integrated Epigenomic Studies (ARIES) at midlife, we found DNAm-Alc explained 7.6% of the variation in alcohol intake, roughly half of what had been reported previously, and interestingly explained a larger 9.8% of Alcohol Use Disorders Identification Test (AUDIT) score, a scale of alcohol use disorder. Explanatory capacity in participants from the offspring generation of ARIES measured during adolescence was much lower. However, DNAm-Alc explained 14.3% of the variation in replication using the Head and Neck 5000 (HN5000) clinical cohort that had higher average alcohol consumption. To investigate whether this relationship was being driven by genetic and/or earlier environment confounding, we examined how earlier versus concurrent DNAm-Alc measures predicted AUDIT scores. In both ARIES parental and offspring generations, we observed associations between AUDIT and concurrent, but not earlier DNAm-Alc, suggesting independence from genetic and stable environmental contributions. Conclusions The stronger relationship between DNAm-Alcs and AUDIT in parents at midlife compared to adolescents despite similar levels of consumption suggests that DNAm-Alc likely reflects long-term patterns of alcohol abuse. Such biomarkers may have potential applications for biomonitoring and risk prediction, especially in cases where reporting bias is a concern.

Dose–Response Characteristics of the Alcohol Biomarker Phosphatidylethanol (PEth)—A Study of Outpatients in Treatment for Reduced Drinking

AimMeasurement of whole-blood phosphatidylethanol (PEth) offers high sensitivity and specificity as alcohol biomarker. A remaining issue of importance for the routine application is to better establish the relationship between PEth concentration and amount and duration of drinking.MethodsThe study included 36 subjects (32–83 years) voluntarily attending outpatient treatment for reduced drinking. At ~ 3- to 4-week intervals, they provided a diary on their daily alcohol intake and gave blood samples for measurement of PEth and carbohydrate-deficient transferrin (CDT). Whole-blood PEth 16:0/18:1 was measured by liquid chromatography-tandem mass spectrometry and serum CDT (%disialotransferrin) by high-performance liquid chromatography.ResultsAt start, the self-reported past 2-week alcohol intake ranged 0–1260 (median 330) g ethanol, the PEth 16:0/18:1 concentration ranged 0.05–1.20 (median 0.23) μmol/L, and the CDT value ranged 0.7–13.0% (median 1.5%). At the final sampling after 5–20 (median 12) weeks, neither reported alcohol intake nor PEth and CDT levels differed significantly from the starting values. The PEth concentration showed best association with past 2-week drinking, followed by for intake in the next last week. The changes in PEth concentration vs past 2-week alcohol intake between two successive tests revealed that an increased ethanol intake by ~ 20 g/day elevated the PEth concentration by on average ~ 0.10 μmol/L, and vice versa for decreased drinking.ConclusionsThe PEth concentration correlated well with past weeks alcohol intake, albeit with a large inter-individual scatter. This indicates that it is possible to make only approximate estimates of drinking based on a single PEth value, implying risk for misclassification between moderate and heavy drinking.