Analysis of Cannabinoids in Biological Specimens: An Update

Cannabinoids are still the most consumed drugs of abuse worldwide. Despite being considered less harmful to human health, particularly if compared with opiates or cocaine, cannabis consumption has important medico-legal and public health consequences. For this reason, the development and optimization of sensitive analytical methods that allow the determination of these compounds in different biological specimens is important, involving relevant efforts from laboratories. This paper will discuss cannabis consumption; toxicokinetics, the most detected compounds in biological samples; and characteristics of the latter. In addition, a comprehensive review of extraction methods and analytical tools available for cannabinoid detection in selected biological specimens will be reviewed. Important issues such as pitfalls and cut-off values will be considered.

Drug testing in support of the diagnosis of neonatal abstinence syndrome: The current situation

Illicit drug use during pregnancy is a concern worldwide, with many international studies describing attempted strategies to mitigate this problem. Drug misuse during pregnancy is associated with significant maternal as well as perinatal complications, which include a high incidence of stillbirths, fetal distress, neonatal abstinence syndrome (NAS) and increased neonatal mortality. Unfortunately, the identification of a drug-exposed mother or neonate is challenging. Maternal disclosure of drug use is often inaccurate, principally due to psychosocial factors including behavioral denial or the fear of the consequences resulting from such admissions. Likewise, many infants who have been exposed to drugs in utero may appear normal at birth and initially show no overt manifestations of drug effects. Thus, the identification of the drug-exposed infant requires a high index of clinical suspicion. Conversely, analytical testing is an objective means of determining drug exposure when it may be necessary to document proof of the infant's exposure to illicit drugs. The review will discuss the different matrices that are most commonly used for testing (e.g., maternal urine, neonatal urine, meconium, and umbilical cord), the strengths and limitations for each matrix, which drugs and metabolites are appropriate for testing, the various testing methods, and the advantages and disadvantages of each method.

Can Umbilical Cord and Meconium Results Be Directly Compared? Analytical Approach Matters

Maternal drug use during pregnancy is a significant concern. Drug-exposed newborns are often born premature and may suffer from birth defects, neonatal abstinence syndrome and cognitive and developmental delays. Because of this, testing of neonatal specimens is carried out to assess fetal drug exposure during pregnancy. Umbilical cord tissue (UC) and meconium are commonly used specimens for this purpose. However, comprehensive studies comparing drug positivity rates and concentration in the two specimen types are lacking. To this end, 4,036 paired UC and meconium specimens originating from 13 states within the USA were identified, and retrospective analysis of drug positivity rates and drug concentration was performed for 31 analytes in 5 drug classes. Testing for 11-Nor-9-carboxy-tetrahydrocannabinol (THC-COOH) is a separate orderable for UC specimen at our laboratory, so a second data set was created for evaluation of this drug analyte with 2,112 paired UC and meconium specimens originating from 11 states. Testing of UC was performed by semi-quantitative liquid chromatography-tandem mass spectrometry (LC-MS-MS) assays, whereas, for meconium, an immunoassay-based screening preceded LC-MS-MS confirmation tests. Results generated for UC and meconium specimens were therefore compared for a total of 32 drug analytes from 6 drug classes. Drug concentrations for analytes were higher in meconium compared to UC, with the exception of phencyclidine. Despite this, the positivity rates for individual analytes were higher in UC, with the exception of THC-COOH and cocaine. Furthermore, analysis for multidrug positivity revealed that THC-COOH and opioids were the most common multidrug combination detected in both matrices. In conclusion, this study suggests that for most drug compounds, UC was more analytically sensitive to assess neonatal drug exposure by current methodologies. Additionally, by demonstrating that meconium has higher drug concentrations for most compounds, this study sets the stage for developing more sensitive assays in meconium.

Quantification of prenatal marijuana use: evaluation of the correlation between self-report, serum, urine and umbilical cord assays among women delivering at two urban Colorado hospitals

BACKGROUND AND AIMS

To estimate during pregnancy correlations between frequency of self-reported use of marijuana and quantified marijuana metabolite in biospecimens including urine, sera and umbilical cord homogenate.

DESIGN

Prospective cohort.

SETTING

Two urban hospitals in Colorado with legal recreational and medicinal marijuana.

PARTICIPANTS

Pregnant women (<16 weeks gestation) self-reporting marijuana use.

MEASUREMENTS

Participants completed a written self-report survey and provided biospecimens at <16 weeks gestation (n = 46), 18 to 22 weeks gestation (n = 43), 32 to 36 weeks gestation (n = 39), and delivery (n = 37). Self-reported marijuana use frequency was calculated based on past-month days of use multiplied by number of daily uses. Maternal urine and sera were tested for presence (>5 ng/mL) of 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH). Liquid chromatography tandem mass spectrometry quantified THC-COOH in umbilical cord homogenate (ng/g). Last marijuana use by any measure was recorded to evaluate the time frame over which THC-COOH remains detectable (>0.10 ng/g) in cord.

FINDINGS

From December 2017 through May 2019, 51 pregnant women enrolled, and 46 were included in analyses (2 withdrew and 3 had a spontaneous abortion). The majority were normal weight, White or Black race, and insured by Medicaid. At the time of enrollment between 7 to 15 weeks' gestation, 87% had ongoing use by self-report, or positive urine or serum. The majority (33 [66%]) stopped using before delivery. Sera and urine results were strongly correlated with self-reported use frequency (Spearman correlation coefficient [r] range 0.70-0.87 across visits, P < 0.001), and with each other. There was only one positive cord result when use stopped before 22 weeks. Frequency of self-reported marijuana use at delivery had strong correlation with quantified cord THC-COOH (r = 0.80, 95% CI = 0.62-0.89).

CONCLUSIONS

Quantified umbilical cord THC-COOH appears to strongly correlate with frequency of maternal marijuana use in the last month of pregnancy. Earlier use can be measured by either quantitative urine or serum assay.

Umbilical Cord Drug Screening in Multiple Births: Experience from a Reference Laboratory and Academic Medical Center

The objective of this study was to review the results of umbilical cord drug screening in twins and triplets (multiples) to compare drug(s) and/or drug metabolite(s) detected. Results that did not agree between multiples were considered mismatched and were investigated. A retrospective analysis was conducted using de-identified data from a national reference laboratory, and results were compared with data from an academic medical center, where detailed medical chart review was performed. Umbilical cord was analyzed for stimulants, sedatives, opioids, and other drugs and metabolites. For the reference laboratory dataset, 23.3% (n=844) of 3,616 umbilical cords from twins (n=3,550) or triplets (n=66) were positive for one or more drugs and/or metabolites. Of these, mismatched results were identified for thirty-seven sets of twins (2.1%) and no sets of triplets. The most frequent mismatches were found in opioids (n=24), with morphine (n=5) being the most mismatched of any single analyte in the panel. Mismatches for the marijuana metabolite 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (9-COOH-THC) in the reference laboratory dataset occurred in six of 737 sets of twins (0.8%) and no triplets. For the academic medical center dataset, 21.9% (n=57) of 260 umbilical cords tested positive for one or more drugs and/or metabolite(s). Of these, 4 mismatches (3.2%) were identified, including 9-COOH-THC (n=2), phentermine (n=1), and oxycodone (n=1), all involving twins. All involved cases where the discrepant analyte was likely present in the negative twin but either slightly below reporting cutoff threshold, or failed analytical quality criteria. Mismatched results of umbilical cord drug screening occur in less than 4% of twins and most often occur when the analyte is slightly above the reporting cutoff in just one infant.

Monitoring Perinatal Exposure to Cannabis and Synthetic Cannabinoids

PURPOSE

Drug use during pregnancy is a critical global challenge, capable of severe impacts on neonatal development. However, the consumption of cannabis and synthetic cannabinoids is on the rise in pregnant women. Obstetric complications with increased risks of miscarriage, fetal growth restriction, and brain development impairment have been associated with perinatal cannabis exposure, but data on synthetic cannabinoid use during pregnancy are limited.

METHODS

We reviewed studies that investigated the risks associated with cannabis and synthetic cannabinoid use and those that reported the concentrations of cannabinoids and synthetic cannabinoids in maternal (breast milk) and neonatal (placenta, umbilical cord, meconium, and hair) matrices during human pregnancy. A MEDLINE and EMBASE literature search to identify all relevant articles published in English from January 1998 to April 2019 was performed.

RESULTS

Cannabis use during pregnancy is associated with increased risks of adverse obstetrical outcomes, although neurobehavioral effects are still unclear. Analyses of cannabinoids in meconium are well documented, but further research on other unconventional matrices is needed. Adverse effects due to perinatal synthetic cannabinoid exposure are still unknown, and analytical data are scarce.

CONCLUSIONS

Awareness of the hazards of drug use during pregnancy should be improved to encourage health care providers to urge pregnant women to abstain from cannabis and, if cannabis-dependent, seek treatment. Moreover, substances used throughout pregnancy should be monitored as a deterrent to cannabis use, and potential cannabis-dependent women should be identified, so as to limit cannabis-fetal exposure during gestation, and provided appropriate treatment.

Screening for Opioid and Stimulant Exposure In Utero Through Targeted and Untargeted Metabolomics Analysis of Umbilical Cords

BACKGROUND

Neonatal abstinence syndrome is an array of signs and symptoms experienced by a newborn due to abrupt discontinuation of intrauterine exposure to certain drugs, primarily opioids. In the United States, the incidence of neonatal abstinence syndrome has tripled over the past decade. The current standard of care for drug testing includes the analysis of infant urine and meconium. Sample collection is associated with several limitations, including diaper media interferences, limited sample amount, sample heterogeneity, and the need for professional staff for collection. Umbilical cord tissue has emerged as a convenient sample matrix for testing owing to its universal availability. The purpose of this study was to examine umbilical cords using an untargeted metabolomics approach to determine the detected drugs and validate an analytical method to confirm and quantify the identified drugs.

METHODS

A metabolomics analysis was performed with 21 umbilical cords to screen for drugs and drug metabolites by liquid chromatography-mass spectrometry. Drugs were identified using the National Institute of Standards and Technology database, and an analytical method was developed and validated using secondary liquid chromatography-mass spectrometry instrument for positive confirmation and quantitative analysis.

RESULTS

Twenty-one random umbilical cords from women were tested: 4 were positive for cocaine and the primary and secondary metabolites; one was positive for methadone, the primary metabolite; 3 were positive for cotinine, the metabolite of nicotine; and 5 were positive for acetyl norfentanyl.

CONCLUSIONS

Our research is a prospective method development study using untargeted and targeted approaches to characterize steady-state drug metabolite levels in the umbilical cord matrix at the time of delivery. By characterizing drug type and concentration, this methodology can be used to develop a reliable complementary testing method for meconium toxicology screens.

Umbilical cord as an analytical matrix - A technical note

The umbilical cord (UC) connects the fetal blood supply to the placenta, so is exposed to all systemic endo- and xenobiotics. We have extensive experience using UC as an analytical matrix for detecting and/or quantitating drugs, chemicals and endogenous compounds. This technical note describes advantages (large amount available, ease of collection, small sample needed for use, rapid availability) and challenges (clinical relationships, processing difficulties, matrix effects on analytes and detection technologies) of UC as an analytical matrix in ELISA and LC/MS platforms, and provides guidance for successfully working with this tissue.

Alternate Matrices: Meconium, Cord Tissue, Hair, and Oral Fluid

Drug testing commonly involves serum, blood, or urine. More recently, alternative specimens for drug testing have been increasingly used for clinical and forensic toxicology. Examples include oral fluid (saliva), hair, meconium, and umbilical cord tissue. Each of these matrices has unique properties that provide advantages for certain applications. Oral fluid has easier and less invasive collection requirements than urine, the most common specimen for drug screening. Oral fluid drug testing is common in Europe and steadily gaining popularity in the United States. Hair accumulates drugs and drug metabolites and provides a much longer window of detection than blood or urine. Meconium and umbilical cord tissue each allow for assessment of prenatal drug exposure over the course of months. Limitations of these alternative matrices include need for laboratory-developed tests (exception being some oral fluid immunoassays), challenges with the specimen matrix, and incomplete understanding of drug incorporation and kinetics. This chapter briefly describes each of the above alternative specimens in terms of their utility, advantages, and limitations.

Cannabis and Its Secondary Metabolites: Their Use as Therapeutic Drugs, Toxicological Aspects, and Analytical Determination

Although the medicinal properties of Cannabis species have been known for centuries, the interest on its main active secondary metabolites as therapeutic alternatives for several pathologies has grown in recent years. This potential use has been a revolution worldwide concerning public health, production, use and sale of cannabis, and has led inclusively to legislation changes in some countries. The scientific advances and concerns of the scientific community have allowed a better understanding of cannabis derivatives as pharmacological options in several conditions, such as appetite stimulation, pain treatment, skin pathologies, anticonvulsant therapy, neurodegenerative diseases, and infectious diseases. However, there is some controversy regarding the legal and ethical implications of their use and routes of administration, also concerning the adverse health consequences and deaths attributed to marijuana consumption, and these represent some of the complexities associated with the use of these compounds as therapeutic drugs. This review comprehends the main secondary metabolites of Cannabis, approaching their therapeutic potential and applications, as well as their potential risks, in order to differentiate the consumption as recreational drugs. There will be also a focus on the analytical methodologies for their analysis, in order to aid health professionals and toxicologists in cases where these compounds are present.

Umbilical Cord Tissue and Meconium May Not Be Equivalent for Confirming in Utero Substance Exposure

In a retrospective study of 501 neonates with potential in utero substance exposure, the drug detection performance of a commercially available umbilical cord tissue toxicology test was evaluated against a commercially available gold standard meconium toxicology test. Drugs detected in paired meconium and umbilical cord tissue samples were often discordant.

Detection of In Utero Cannabis Exposure in Umbilical Cord Tissue by a Sensitive Liquid Chromatography-Tandem Mass Spectrometry Method

In utero exposure to cannabis may cause various short- and long-term health problems in newborns, such as low birth weight and neonatal withdrawal syndrome. Drug testing with umbilical cord tissue can be used to identify in utero exposure to cannabis. Here, we described a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method that simultaneously quantifies four cannabinoids in umbilical cord tissue, including tetrahydrocannabinol (THC), 11-nor-Δ9-carboxy-THC (THC-COOH), cannabinol (CBN), and 11-hydroxy-THC (11-OH-THC). Umbilical cord specimens are weighed and homogenized, and cannabinoids are extracted using anion exchange solid-phase extraction columns (AX-SPE). Liquid chromatography separation is performed, and quantitative results are obtained using LC-MS/MS.

Development of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of Four Cannabinoids in Umbilical Cord Tissue

In utero exposure to marijuana may cause various short- and long-term health problems, such as stillbirth, low birth weight and decreased cognitive function. Detection of in utero marijuana exposure with a relatively new specimen type, umbilical cord tissue, can be used to plan treatment and guide social management. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS-MS) assay was developed for the simultaneous identification of four cannabinoids in umbilical cord tissue, including ∆9-tetrahydrocannabinol (THC), 11-nor-9-carboxy-∆9--THC (THC-COOH), 11-hydroxy-∆9-THC (11-OH-THC) and cannabinol (CBN). Within- and between-run imprecision, accuracy, linearity, sensitivity, carryover, recovery, matrix effects and specificity were evaluated using drug-free umbilical cord tissue spiked with non-deuterated and deuterated standards. Calibration curves were reproducible and linear (r > 0.995) for all four analytes in the range of 0.2 ng/g lower limit of quantitation (LLOQ) and 30 ng/g upper limit of quantitation (ULOQ). Total imprecisions (% coefficient of variation) were 7.8% (THC), 13.3% (THC-COOH), 11.8% (11-OH-THC) and 10.6% (CBN) at low QC (n = 15, 0.25 ng/g), and were 7.2% (THC), 10.0% (THC-COOH), 9.5% (11-OH-THC) and 5.8% (CBN) at high QC (n = 15, 4 ng/g), respectively. No interfering substances were identified, and no carryover was observed. The average accuracies (N = 25) were 94-95%. The average recoveries observed for THC, THC-COOH, 11-OH-THC and CBN were 74, 82, 58 and 86%, respectively. By analyzing authentic clinical specimens that had been previously tested for cannabinoids by enzyme-linked immunoassay, positive and negative result agreements were 100 and 53.8%. In summary, the presented method can be used for the assessment of in utero exposure to four common cannabinoids.

Drug exposure during pregnancy: analytical methods and toxicological findings

Drug use during pregnancy constitutes a major preventable worldwide public health issue. Birth defects, growth retardation and neurodevelopmental disorders are associated with tobacco, alcohol or drugs of abuse exposure during pregnancy. Besides these adverse health effects, drug use during pregnancy also raises legal and social concerns. Identification and quantification of drug markers in maternal and newborn biological samples offers objective evidence of exposure and complements maternal questionnaires. We reviewed the most recent analytical methods for quantifying drugs of abuse, tobacco, alcohol and psychotropic drugs in maternal, newborn and maternal-fetal unit biological samples by gas and liquid chromatography coupled to mass spectrometry. In addition, manuscripts comparing the usefulness of different biological samples to detect drug exposure during pregnancy were reviewed.

Simultaneous accelerated solvent extraction and hydrolysis of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid glucuronide in meconium samples for gas chromatography-mass spectrometry analysis

Cannabis misuse during pregnancy is associated with severe impacts on the mother and baby health, such as newborn low birth weight, growth restriction, pre-term birth, neurobehavioral and developmental deficits. In most of the cases, drug abuse is omitted or denied by the mothers. Thus, toxicological analyzes using maternal-fetal matrices takes place as a suitable tool to assess drug use. Herein, meconium was the chosen matrix to evaluate cannabis exposure through identification and quantification of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic (THCCOOH). Accelerated solvent extraction (ASE) was applied for sample preparation technique to simultaneously extract and hydrolyze conjugated THCCOOH from meconium, followed by a solid-phase extraction (SPE) procedure. The method was developed and validated for gas chromatography-mass spectrometry (GC-MS), reaching hydrolysis efficiency of 98%. Limits of detection (LOD) and quantification (LOQ) were, respectively, 5 and 10 ng/g. The range of linearity was LOQ to 500 ng/g. Inter and intra-batch coefficients of variation were <8.4% for all concentration levels. Accuracy was in 101.7-108.9% range. Recovery was on average 60.3%. Carryover effect was not observed. The procedure was applied in six meconium samples from babies whose mothers were drug users and showed satisfactory performance to confirm fetal cannabis exposure.

Comparison of umbilical cord tissue and meconium for the confirmation of in utero drug exposure

OBJECTIVES

Drug screening in neonates is traditionally performed using meconium, but cord tissue has been proposed as an alternative specimen. This study compares the detection of drugs in a large number of paired meconium and umbilical cord tissue samples from subjects at risk of in utero drug exposure.

DESIGN AND METHODS

Physician-ordered toxicology results and clinical information were collected in a retrospective review of subject medical records. All toxicology testing was performed by a national reference laboratory using a combination of immunoassays and chromatography-mass spectrometry. The comparison was limited to drugs present in both cord and meconium panels.

RESULTS

Overall agreement between cord and meconium ranged from 76% (cannabinoids) to 100% (barbiturates), but Cohen's kappa was <65% for 5 of the 6 drug classes we studied. Considering meconium as the gold standard, cord was less sensitive for the detection of 5 of the 6 drug classes, and for the detection of all 5 individual opioids. For 3 of the 5 individual opioids, the concentration of drug measured in meconium did not correlate well with qualitative detection in cord.

CONCLUSIONS

This study reveals different sensitivities of drug detection in umbilical cord tissue and meconium. For the drugs studied here, meconium provides greater sensitivity, and is likely to remain the specimen of choice when sensitivity is of greatest importance. These results can help clinicians, laboratorians, and epidemiologists to (1) select the most appropriate test to confirm a suspected drug exposure and (2) interpret discordant results when testing is performed in multiple matrices.

Trends in the application of high-resolution mass spectrometry for human biomonitoring: An analytical primer to studying the environmental chemical space of the human exposome

Global profiling of xenobiotics in human matrices in an untargeted mode is gaining attention for studying the environmental chemical space of the human exposome. Defined as the study of a comprehensive inclusion of environmental influences and associated biological responses, human exposome science is currently evolving out of the metabolomics science. In analogy to the latter, the development and applications of high resolution mass spectrometry (HRMS) has shown potential and promise to greatly expand our ability to capture the broad spectrum of environmental chemicals in exposome studies. HRMS can perform both untargeted and targeted analysis because of its capability of full- and/or tandem-mass spectrum acquisition at high mass accuracy with good sensitivity. The collected data from target, suspect and non-target screening can be used not only for the identification of environmental chemical contaminants in human matrices prospectively but also retrospectively. This review covers recent trends and advances in this field. We focus on advances and applications of HRMS in human biomonitoring studies, and data acquisition and mining. The acquired insights provide stepping stones to improve understanding of the human exposome by applying HRMS, and the challenges and prospects for future research.

Bioanalysis during pregnancy: recent advances and novel sampling strategies

Consumption of drugs of abuse, tobacco and alcohol throughout pregnancy is a serious public health problem and results in an important economic cost to the health system. Drug and/or metabolites determination in biological matrices from mother and newborn is an objective measure of in utero drug exposure. We reviewed methods published for the determination of in utero drug exposure from 2007 to 2014, with special focus on meconium, placenta, umbilical cord and newborn hair. Accurate bioanalytical procedures are essential to obtain high-quality data to perform interventions and to establish correlations between analytical measures and clinical outcomes. We included a brief overview of clinical implications of in utero drug exposure to better understand the importance of this serious health issue.