Testing for ethanol markers in hair: Discrepancies after simultaneous quantification of ethyl glucuronide and fatty acid ethyl esters

Biomarkers of moderate alcohol intake and alcoholic beverages: a systematic literature review

The predominant source of alcohol in the diet is alcoholic beverages, including beer, wine, spirits and liquors, sweet wine, and ciders. Self-reported alcohol intakes are likely to be influenced by measurement error, thus affecting the accuracy and precision of currently established epidemiological associations between alcohol itself, alcoholic beverage consumption, and health or disease. Therefore, a more objective assessment of alcohol intake would be very valuable, which may be established through biomarkers of food intake (BFIs). Several direct and indirect alcohol intake biomarkers have been proposed in forensic and clinical contexts to assess recent or longer-term intakes. Protocols for performing systematic reviews in this field, as well as for assessing the validity of candidate BFIs, have been developed within the Food Biomarker Alliance (FoodBAll) project. The aim of this systematic review is to list and validate biomarkers of ethanol intake per se excluding markers of abuse, but including biomarkers related to common categories of alcoholic beverages. Validation of the proposed candidate biomarker(s) for alcohol itself and for each alcoholic beverage was done according to the published guideline for biomarker reviews. In conclusion, common biomarkers of alcohol intake, e.g., as ethyl glucuronide, ethyl sulfate, fatty acid ethyl esters, and phosphatidyl ethanol, show considerable inter-individual response, especially at low to moderate intakes, and need further development and improved validation, while BFIs for beer and wine are highly promising and may help in more accurate intake assessments for these specific beverages.

What the lab can and cannot do: clinical interpretation of drug testing results

Urine drug testing is one of the objective tools available to assess adherence. To monitor adherence, quantitative urinary results can assist in differentiating "new" drug use from "previous" (historical) drug use. "Spikes" in urinary concentration can assist in identifying patterns of drug use. Coupled chromatographic-mass spectrometric methods are capable of identifying very small amounts of analyte and can make clinical interpretation rather challenging, specifically for drugs that have a longer half-life. Polypharmacy is common in treatment and rehabilitation programs because of co-morbidities. Medications prescribed for comorbidities can cause drug-drug interaction and phenoconversion of genotypic extensive metabolizers into phenotypic poor metabolizers of the treatment drug. This can have significant impact on both pharmacokinetic (PK) and pharmacodynamic properties of the treatment drug. Therapeutic drug monitoring (TDM) coupled with PKs can assist in interpreting the effects of phenoconversion. TDM-PKs reflects the cumulative effects of pathophysiological changes in the patient as well as drug-drug interactions and should be considered for treatment medications/drugs used to manage pain and treat substance abuse. Since only a few enzyme immunoassays for TDM are available, this is a unique opportunity for clinical laboratory scientists to develop TDM-PK protocols that can have a significant impact on patient care and personalized medicine. Interpretation of drug screening results should be done with caution while considering pharmacological properties and the presence or absence of the parent drug and its metabolites. The objective of this manuscript is to review and address the variables that influence interpretation of different drugs analyzed from a rehabilitation and treatment programs perspective.

Determination of ethyl glucuronide in human hair samples: Decontamination vs extraction

Decontamination of samples prior to analysis is common practice and recommended for ethyl glucuronide (EtG) hair testing. The aim of this study was to evaluate the applied decontamination procedure during routine hair EtG analysis by monitoring the ethyl glucuronide concentrations in the washing solutions from a representative cohort of individual hair samples. Hair samples from 150 individuals were tested for hair EtG by a validated routine procedure (liquid chromatography/tandem mass spectrometry). A four-step decontamination procedure (ethanol, water, acetone, dichloromethane) was applied to all samples prior to analysis. Hair samples from 20 individuals were analyzed along with the complete set of individual washing solutions. Hair samples from an additional 130 individuals were analyzed along with the corresponding aqueous wash fraction only. No EtG was detected in the washing solutions from hair samples that tested negative for EtG (n = 42). Hair samples positive for ethyl glucuronide (n = 108) were found to liberate different amounts of EtG during decontamination: whereas no, or low portions of, EtG (< 10% of extracted hair EtG) were found in the corresponding washing solutions of the majority (n = 91) of individual samples, there was a minority of samples (n = 6) with more than half of the extracted hair EtG present in the decontamination solvent. No correlation of the decontaminated amount of EtG and the extracted hair EtG was observed. Further experimental studies are necessary to investigate if the observed easily removable fraction of EtG is associated with external contamination and if analysis of wash solutions could be helpful for identifying external contamination in hair testing for ethyl glucuronide.

An Optimized Solid-Phase Microextraction and Gas Chromatography–Mass Spectrometry Assay for the Determination of Ethyl Palmitate in Hair

The use of hair as a matrix for the evaluation of chronic ethanol drinking behavior presents the advantage of a longer window of detection and higher specificity when compared to classical biochemical markers. The most recent recommendations the Society of Hair Testing (SOHT) indicate that ethyl palmitate (EtP) hair levels can be used to estimate the ethanol drinking behavior, alternatively to the combined measurement of four main fatty acid ethyl esters. In this study, solid-phase microextraction (SPME) conditions for the extraction of EtP from hair were optimized using response surface analysis, after a Box–Behnken experiment. Analyses were performed by GC-MS. The optimized HS-SPME conditions, using a PDMS-DVB (65 μm) fiber, were pre-adsorption time of 6 min, extraction time of 60 min and incubation temperature of 94°C. The linear range was 0.05 to 3 ng mg−1, with accuracy within 95.15–109.91%. Between-assay and within-assay precision were 8.58–12.53 and 6.12–6.82%, respectively. The extraction yield was 61.3–71.9%. The assay was applied to hair specimens obtained from 46 volunteers, all presenting EtP levels within the linear range of the assay. Using a statistically designed experiment, a sensitive SPME-GC-MS assay for the measurement of EtP in hair was developed and validated, requiring only 20 mg of hair.

Ethyl Glucuronide in Alcoholic Beverages

Aims

This study examines the biomarker ethyl glucuronide (EtG) in various alcoholic beverages.

Short summary

The biomarker EtG was consistently found to be a natural compound of wine, whereas it was not detected in any of the other tested alcoholic beverages, which included various distilled spirits, liqueurs and beer of different types and geographical origins.

Methods

Alcoholic beverages (n = 114) were analyzed by a validated liquid chromatography/tandem mass spectrometry assay. Beverages included samples from beer, wine, liqueurs and spirits from different manufacturers and geographical origins.

Results

EtG was not detected in any kind of distilled alcoholic beverages, regardless of the type of spirit (rum, gin, vodka, whiskey, fruit brandy, corn brandy, cordial) or liqueur (n = 52). EtG was also not detected in any of the analyzed samples of beer, which included pilsener, weissbier, lager beer and ale from different origins (n = 20). In contrast, EtG was detected in every of the analyzed samples of wine (n = 42) without exception. Highest amounts were found in red wine and ranged from 1425 to 3720 μg/l (n = 16). Significantly, lower concentrations of EtG were observed for white wine (347-1685 μg/l, n = 14) and sparkling wine (281-1447 μg/l, n = 10).

Conclusions

Wine is an external source of EtG. It has been shown that milligram amounts of the biomarker can be contained in a bottle of wine. This should be considered in biomarker testing, especially in EtG hair analysis, which is susceptible to external contamination.

Substance use in individuals with mild to borderline intellectual disability: A comparison between self-report, collateral-report and biomarker analysis

BACKGROUND AND AIMS

Individuals with mild or borderline intellectual disability (MBID) are at risk of substance use (SU). At present, it is unclear which strategy is the best for assessing SU in individuals with MBID. This study compares three strategies, namely self-report, collateral-report, and biomarker analysis.

METHODS AND PROCEDURES

In a sample of 112 participants with MBID from six Dutch facilities providing care to individuals with intellectual disabilities, willingness to participate, SU rates, and agreement between the three strategies were explored. The Substance use and misuse in Intellectual Disability - Questionnaire (SumID-Q; self-report) assesses lifetime use, use in the previous month, and recent use of tobacco, alcohol, cannabis, and stimulants. The Substance use and misuse in Intellectual Disability - Collateral-report questionnaire (SumID-CR; collateral-report) assesses staff members' report of participants' SU over the same reference periods as the SumID-Q. Biomarkers for SU, such as cotinine (metabolite of nicotine), ethanol, tetrahydrocannabinol (THC), and its metabolite THCCOOH, benzoylecgonine (metabolite of cocaine), and amphetamines were assessed in urine, hair, and sweat patches.

RESULTS

Willingness to provide biomarker samples was significantly lower compared to willingness to complete the SumID-Q (p<0.001). Most participants reported smoking, drinking alcohol, and using cannabis at least once in their lives, and about a fifth had ever used stimulants. Collateralreported lifetime use was significantly lower. However, self-reported past month and recent SU rates did not differ significantly from the rates from collateral-reports or biomarkers, with the exception of lower alcohol use rates found in biomarker analysis. The agreement between self-report and biomarker analysis was substantial (kappas 0.60-0.89), except for alcohol use (kappa 0.06). Disagreement between SumID-Q and biomarkers concerned mainly over-reporting of the SumID-Q. The agreement between SumID-CR and biomarker analysis was moderate to substantial (kappas 0.48 - 0.88), again with the exception of alcohol (kappa 0.02).

CONCLUSIONS AND IMPLICATIONS

In this study, the three strategies that were used to assess SU in individuals with MBID differed significantly in participation rates, but not in SU rates. Several explanations for the better-than-expected performance of self- and collateral-reports are presented. We conclude that for individuals with MBID, self-report combined with collateralreport can be used to assess current SU, and this combination may contribute to collaborative, early intervention efforts to reduce SU and its related harms in this vulnerable group.

Alternative sampling strategies for the assessment of alcohol intake of living persons

Monitoring of alcohol consumption by living persons takes place in various contexts, amongst which workplace drug testing, driving under the influence of alcohol, driving licence regranting programs, alcohol withdrawal treatment, diagnosis of acute intoxication or fetal alcohol ingestion. The matrices that are mostly used today include blood, breath and urine. The aim of this review is to present alternative sampling strategies that allow monitoring of the alcohol consumption in living subjects. Ethanol itself, indirect (carbohydrate deficient transferrin, CDT%) as well as direct biomarkers (ethyl glucuronide, EtG; ethyl sulphate, EtS; fatty acid ethyl esters, FAEEs and phosphatidylethanol species, PEths) of ethanol consumption will be considered. This review covers dried blood spots (CDT%, EtG/EtS, PEths), dried urine spots (EtG/EtS), sweat and skin surface lipids (ethanol, EtG, FAEEs), oral fluid (ethanol, EtG), exhaled breath (PEths), hair (EtG, FAEEs), nail (EtG), meconium (EtG/EtS, FAEEs), umbilical cord and placenta (EtG/EtS and PEth 16:0/18:1). Main results, issues and considerations specific to each matrix are reported. Details about sample preparation and analytical methods are not within the scope of this review.

Determination of Ethyl Glucuronide in Hair for Detection of Alcohol Consumption in Patients After Liver Transplantation

BACKGROUND

Early detection of alcohol misuse in orthotopic liver transplantation recipients is essential to offer patients support and prevent organ damage. Here, ethyl glucuronide, a metabolite of ethanol found in hair (hEtG), was evaluated for detection of alcohol consumption.

METHODS

In 104 transplant recipients, 31 with underlying alcoholic liver disease (ALD) and 73 with non-ALD, hEtG was determined in addition to the alcohol markers urine EtG, blood ethanol, methanol, and carbohydrate-deficient transferrin. Results were compared with patients' self-reports in a questionnaire and with physicians' assessments.

RESULTS

By physicians' assessments, 22% of the patients were suspected of consuming alcohol regularly, although only 6% of the patients acknowledged consumption of a moderate or high amount of alcohol. By testing all markers except for hEtG, alcohol consumption was detected in 7% of the patients. When hEtG testing was added to the assessment, consumption was detected in 17% of the patients. Hair-EtG determination alone revealed chronic alcohol consumption of >10 g/d in 15% of the patients. ALD patients had a positive hEtG result significantly more often than non-ALD patients did (32% versus 8%; P = 0.003). Also, the concentration of hEtG was higher in ALD patients (P = 0.049) and revealed alcohol abuse with consumption of >60 g ethanol per day in 23% of ALD and 3% of non-ALD patients. Patients' self-reports and physicians' assessments had a low sensitivity of 27% and 67%, respectively, for detecting regular alcohol intake as indicated by hEtG.

CONCLUSIONS

Hair-EtG determination improved the detection of liver transplant patients who used alcohol, and revealed regular alcohol consumption in 32% of ALD and 8% of non-ALD patients.

Segmental hair analysis to assess effectiveness of single-session motivational intervention to stop ethanol use during pregnancy

BACKGROUND

This study aimed to test the effectiveness of single-session motivational intervention to stop ethanol use during pregnancy using segmental hair analysis of ethyl glucuronide to objectively verify drinking behavior before and after intervention.

METHODS

168 pregnant women attending Hospital del Mar (Barcelona, Spain) for antenatal visit were included in the study and randomly assigned to one of two conditions: single-session motivational intervention (MI; N=83) or single-session educational control condition (ECC; N=85). Ethyl glucuronide was measured in maternal hair divided into three segments of 3 cm each corresponding to the three different gestation trimesters by a validated liquid chromatography tandem mass spectrometry method. Concentrations of EtG<7 pg/mg, between 7 and 30 pg/mg and ≥30 pg/mg in each segment were used to assess total abstinence, repetitive moderate drinking and chronic excessive consumption in the previous three months.

RESULTS

About a third of pregnant women self-reporting no ethanol consumption during gestation showed hair EtG values corresponding to ethanol drinking. Single-session MI helped in decreasing alcohol consumption during pregnancy as assessed by lower hair EtG concentrations in 2nd and 3rd trimesters. However, it did not significantly increase complete abstinence in pregnant women who previously showed hair EtG compatible with ethanol consumption.

CONCLUSIONS

Pregnant women did not correctly self reported ethanol consumption during gestation, while hair EtG was essential to correctly identify drinking patterns. Single-session MI was not enough to stop ethanol use during pregnancy. Interventions at any visit during pregnancy are strongly recommended.

Improved radiocarbon analyses of modern human hair to determine the year-of-death by cross-flow nanofiltered amino acids: common contaminants, implications for isotopic analysis, and recommendations

RATIONALE

In forensic investigation, radiocarbon ((14)C) measurements of human tissues (i.e., nails and hair) can help determine the year-of-death. However, the frequent use of cosmetics can bias hair (14)C results as well as stable isotope values. Evidence shows that hair exogenous impurities percolate beyond the cuticle layer, and therefore conventional pretreatments are ineffective in removing them.

METHODS

We conducted isotopic analysis ((14)C, δ(13)C, δ(15)N and C/N) of conventionally treated and cross-flow nanofiltered amino acid (CFNAA)-treated samples (scalp- and body-hair) from a single female subject using fingernails as a reference. The subject studied frequently applies a permanent dark-brown dye kit to her scalp-hair and uses other care products for daily cleansing. We also performed pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses of CFNAA-treated scalp-hair to identify contaminant remnants that could possibly interfere with isotopic analyses.

RESULTS

The conventionally treated scalp- and body-hair showed (14)C offsets of ~21‰ and ~9‰, respectively. These offsets confirm the contamination by petrochemicals in modern human hair. A single CFNAA extraction reduced those offsets by ~34%. No significant improvement was observed when sequential extractions were performed, as it appears that the procedure introduced some foreign contaminants. A chromatogram of the CFNAA scalp-hair pyrolysis products showed the presence of petroleum and plant/animal compound residues, which can bias isotopic analyses.

CONCLUSIONS

We have demonstrated that CFNAA extractions can partially remove cosmetic contaminants embedded in human hair. We conclude that fingernails are still the best source of keratin protein for year-of-death determinations and isotopic analysis, with body-hair and/or scalp-hair coupled with CFNAA extraction a close second.

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions

BACKGROUND

The quantitative, measurable detection of drinking is important for the successful treatment of alcohol misuse in transplantation of patients with alcohol disorders, people living with human immunodeficiency virus that need to adhere to medication, and special occupational hazard offenders, many of whom continually deny drinking. Their initial misconduct usually leads to medical problems associated with drinking, impulsive social behavior, and drunk driving. The accurate identification of alcohol consumption via biochemical tests contributes significantly to the monitoring of drinking behavior.

METHODS

A systematic review of the current methods used to measure biomarkers of alcohol consumption was conducted using PubMed and Google Scholar databases (2010-2015). The names of the tests have been identified. The methods and publications that correlate between the social instruments and the biochemical tests were further investigated. There is a clear need for assays standardization to ensure the use of these biochemical tests as routine biomarkers.

FINDINGS

Alcohol ingestion can be measured using a breath test. Because alcohol is rapidly eliminated from the circulation, the time for detection by this analysis is in the range of hours. Alcohol consumption can alternatively be detected by direct measurement of ethanol concentration in blood or urine. Several markers have been proposed to extend the interval and sensitivities of detection, including ethyl glucuronide and ethyl sulfate in urine, phosphatidylethanol in blood, and ethyl glucuronide and fatty acid ethyl esters in hair, among others. Moreover, there is a need to correlate the indirect biomarker carbohydrate deficient transferrin, which reflects longer lasting consumption of higher amounts of alcohol, with serum γ-glutamyl transpeptidase, another long term indirect biomarker that is routinely used and standardized in laboratory medicine.