Optimizing screening cutoffs for drugs of abuse in hair using immunoassay for forensic applications.

BACKGROUND: In forensic toxicology, positive immunoassay (IA) test results do not hold forensic validity and need to be confirmed with mass spectrometry (MS). On the other hand, a negative result is a strong indication that the drug and/or the drug metabolites are not present in the sample and that confirmatory analyses are not necessary. Consequently, a negative IA result must have forensic validity since it can be admitted in court during a trial. OBJECTIVES: Screening cutoffs for the analysis of hair samples using immunoassays (IAs) were retrospectively optimized based on the Society of Hair Testing (SoHT) confirmation cutoffs and the utility of the test for forensic applications was discussed. MATERIAL AND METHODS: Hair samples taken from 150 patients with a history of drug addiction were analyzed with ILab 650, Werfen (Milan, Italy) using DRI® reagents. Confirmatory analyses were subsequently performed using the ACQUITY UPLC® System, Waters Corporation (Milford, USA). Screening cutoffs were retrospectively optimized using receiver operating characteristic (ROC) analysis. RESULTS: A total of 162 single positive results were obtained for confirmatory analysis (10 for amphetamines/methamphetamines, 11 for MDMA, 37 for cocaine, 40 for THC, 33 for methadone, and 31 for opiates). The optimized screening cutoffs were 0.27 IA ng/mg for amphetamines, 0.51 IA ng/mg for MDMA, 0.59 IA ng/mg for cocaine, 0.14 IA ng/mg for cannabinoids, 0.63 IA ng/mg for methadone, and 0.26 IA ng/mg for opiates. An area under the curve (AUC) greater than 0.95 was obtained with very high sensitivity and specificity for all drugs. CONCLUSIONS: The presented screening method proved to be a useful technique on hair samples for the classes of drugs most commonly found in Italy and Europe and can be applied to forensic analysis.

Optimization of cloned enzyme donor immunoassay cut-offs for drugs of abuse in post-mortem whole blood.

INTRODUCTION: Immunoassay (IA) tests are not widely applied in post-mortem samples, since they are based on technologies requiring relatively non-viscous specimens, and compounds originating from the degradation of proteins and lipids during the post-mortem interval can alter the efficiency of the test. However, since the extraction techniques for IA tests are normally rapid and low-cost, IA could be used as near-body drug-screening for the classes of drugs most commonly found in Italy and Europe. In this study, semi-quantitative results on post-mortem whole blood samples obtained through CEDIA analysis (cannabinoids, cocaine, amphetamine compounds, opiates and methadone), were compared with results of confirmatory analysis obtained using GC-MS. Screening cut-offs for all drugs were retrospectively optimized. METHODS: Post-mortem whole blood samples from autopsy cases of suspected fatal intoxication were collected over 3 years. Samples were initially analyzed through CEDIA (CEDIA, ILab 650, Werfen). Confirmatory analyses were then performed by GC-MS (QP 2010 Plus, Shimadzu). Screening cut-offs were retrospectively optimized using Receiver Operating Characteristic (ROC) analysis. RESULTS: CEDIA results were available for 125 samples. Two-hundred-eighty-nine (289) positive screening results were found. Among these, 162 positive confirmation results were obtained. Optimized screening cut-offs were as follows: 6.5ng/ml for THC; 4.2ng/ml for THC-COOH; 12.0ng/ml for cocaine; 6.6ng/ml for benzoylecgonine; 6.4ng/ml for opiates; 2.0ng/ml for methadone. Analysis of ROC-curves showed a satisfying degree of separation in all tests except for amphetamine compounds, with areas under the curve (AUC) between 0.915 (THC) and 0.999 (for benzoylecgonine and methadone). DISCUSSION: The results of the study showed that CEDIA screening at the optimized cut-offs exhibits a very high sensitivity and good specificity and positive predictive value (PPV) for cannabinoids, cocaine and metabolites, opiates and methadone. A high number of false positives (n=19) for amphetamine compounds was observed at the optimized cut-off, resulting in a very low PPV, which is also influenced by the very low number of TP (n=4). CONCLUSION: The results of the study show that the CEDIA is a valuable screening test on post-mortem whole blood for cannabinoids, cocaine and metabolites, opiates and methadone, but it is not recommended for amphetamine compounds, due to the high number of false positives. The strengths of the study are the large sample size, the inclusion of post-mortem cases only and the high level of sensitivity and specificity obtained at the optimized cut-offs.

Alcohol and illicit drugs in drivers involved in road traffic crashes in Italy. An 8-year retrospective study.

This study aims to investigate the prevalence of alcohol and drugs of abuse in Italian drivers involved in road traffic crashes between 2011 and 2018. Toxicological analyses were performed on the whole blood of 7593 injured drivers. Alcohol and illicit drugs, namely tetrahydrocannabinol (THC; cut-off 2ng/ml), cocaine (cut-off 10ng/ml), illicit opiates (cut-off 10ng/ml) and amphetamines (amphetamine, methamphetamine, MDMA, MDA; cut-off 20ng/ml) were investigated. The age and gender of the driver, the time of the crash (weekend/weekday and day/night), the road crash year and Blood Alcohol Concentration (BAC) were also considered. The 16.2% of samples tested positive for alcohol, 2.5% for cocaine, followed by opiates (2.0%), cannabinoids (1.5%), and amphetamines (0.5%). The overall prevalence of alcohol and drugs was lower than those reported in previous epidemiological studies of the DRUID project. The year 2011 showed the highest prevalence of drug-positive cases (24.1%), while the lowest prevalence was found in 2016 (16.8%), after the update of the Road Traffic Law (RTL) that increased punishments for driving under the influence. A progressive increase in the number of alcohol-positive female drivers was observed from 2011 to 2018, and the highest prevalence was found in the 26-35-year-old age range. Illicit drugs showed the highest overall prevalence in drivers <26 years of age but, if considering single drugs, cocaine and opiates were mostly found in subjects older than 36 years of age. A higher percentage of drug-positive drivers was found on weekend nights for alcohol and on both weekend and weekday nights for drugs. The types of drugs used by drivers did not change during the studied period.

Validation and preliminary application of a GC-MS method for the determination of putrescine and cadaverine in the human brain: a promising technique for PMI estimation.

INTRODUCTION: Among the several techniques proposed for the estimation of the Post Mortem Interval (PMI), the analysis of odorous amines has been applied in the past, with conflicting results. The aims of this study are: (i) to develop and validate a GC-MS method for the determination of putrescine (PUT) and cadaverine (CAD) in the human brain (validation study) and (ii) to study the relation of PUT and CAD concentration in the human brain and the PMI (decomposition study). MATERIALS AND METHODS: Validation study. Analysis has been performed through GC-MS after a liquid-liquid extraction and a single step-derivatization for the identification and quantification of odorous amines in brain cortex samples. The standard protocol used in forensic toxicology, slightly modified for endogenous compounds according to recent guidelines, was used for validation. Decomposition study. Three uninjured human brains were sampled during the autopsy of three fatal traumatic cases. Along a 120-hour period of decomposition under experimental conditions, each brain was sampled along predetermined time intervals. RESULTS: Validation study. Both PUT and CAD validation parameters were within the acceptable values defined by the Scientific Working Group for Forensic Toxicology (SWGTOX), with better selectivity, linearity, accuracy and precision values for PUT. Decomposition study. A significant relationship between PUT and CAD levels and PMI has been demonstrated through statistical analysis with a correlation coefficient of 0.98 for PUT and 0.93 for CAD (p < 0.0001). CONCLUSION: Although further experimental studies on a wider number of samples are necessary, the results of this study suggest a possible role of polyamine levels in brain cortex for the estimation of PMI.

Optimization of cloned enzyme donor immunoassay cut-offs for drugs of abuse in whole blood of drivers involved in road accidents.

INTRODUCTION: Immunoassay (IA) tests should be able to detect low concentrations of illegal drugs when used for the screening of drugs in drivers. False negatives should be avoided, and false positives should be reduced as far as possible. In this study, semi-quantitative results for blood samples containing illicit drugs (cannabinoids, cocaine, amphetamines/methamphetamines, opiates and methadone) obtained with cloned enzyme donor immunoassay (CEDIA), were compared with results of confirmatory analysis performed through gas chromatography-mass spectrometry (GC-MS). Screening cut-off points for each class of drugs were retrospectively optimized. METHODS: Whole blood samples from drivers involved in road accidents in the period from January 2013-December 2017 were analyzed with CEDIA (4200 samples). Confirmatory analyses were performed through (GC-MS) on: (i) all samples with screening concentrations above 1ng/ml for at least one drug (positive screening results); (ii) 800 samples with screening concentration lower than 1ng/ml (negative screening results). Recommended per se limits in relation to driving under the influence of drugs were set as fixed values. Sensitivity, specificity, positive and negative predictive values were evaluated by contingency tables and compared to ROC-analysis in order to obtain ideal screening cut-offs. RESULTS: CEDIA results were available for 4200 blood samples and 1172 positive screening results were found. Among these, 1008 confirmation analysis were obtained through GC-MS. Optimized screening cut-offs obtained through ROC analysis were as follows: 8.0ng/ml for THC; 5.5ng/ml for THC-COOH; 21.1ng/ml for cocaine; 6.9ng/ml for benzoylecgonine; 33.1ng/ml for opiates; 61.6ng/ml for amphetamines; 5.0ng/ml for methadone. Using these cut-offs, sensitivity was above 97% for THC-COOH, cocaine, benzoylecgonine, amphetamines, opiates and methadone, and 92% for THC; specificity was above 90% for cocaine, benzoylecgonine, amphetamines, opiates and methadone, 80% for THC and 89% for THC-COOH; negative predictive value was above 99% for all drugs and metabolites. CONCLUSION: Previous studies have shown that CEDIA tests are useful for preliminary screening of serum and urine. Its implementation in whole blood is of primary importance for the assessment of impaired driving, since the per se limits of many European countries refer to whole blood, and preparation of the serum and/or the collection of urine is not always possible in the hospital emergency department, where blood samples are withdrawn. Our study shows that CEDIA tests on whole blood permit the definition of cut-off values with optimal sensitivity and negative predictive values for all analytes (near to 100%), including very good specificity.

Medico-legal implications of toluene abuse and toxicity. Review of cases along with blood concentrations.

Toluene, a liquid aromatic hydrocarbon, is one of the most widely used industrial solvents, and is present in numerous paints, paint thinners, glues and other industrial and household products. It has become the most abused solvent in the world due to its rapid effects following inhalation. However, the numerous cases of fatal and non-fatal toluene-related intoxication reported in the literature have not yet been collected and discussed in the forensic setting. In this paper we aim to provide a review of the cases of toluene abuse and intoxication and the state of the art of the forensic toxicological analysis of toluene intoxications in the living and in the dead subject, from the early identification to the medico-legal interpretation of the toxicological result. We have identified a total of 45 papers regarding different aspects of toluene abuse, and divided them into three sections, namely sampling, storage and techniques of analysis, assessment in living subjects and post-mortem assessment. This article reports toluene concentrations in blood from 202 living subjects, 23 fatal toluene intoxications and 85 toluene related deaths. Toxicological results are discussed in relation to the clinical presentation (living subjects, including impaired drivers), and the manner of death according to the medical examiner reports (post-mortem examinations). Finally, we discuss the strengths and limitations of the review.

Safe drugs in drug facilitated crimes and acute intoxications in Northern Italy.

Toxicological analyses are often performed in drug-facilitated sexual assaults (DFSA), when the victim shows or reports impaired consciousness and reduced ability. However, in other crimes or fatalities, especially in cases of concurrent natural disease or when another likely cause of death has been established, the involvement of drugs can be overlooked. The aim of this study is to report a series of cases of (i) victims of drug-facilitated crimes (DFC) other than DFSA and (ii) victims of acute intoxications, in which "licit" psychoactive drugs were found in blood samples, with the aim of understanding in which circumstances and to what extent prescription drugs have been used for non-medical purposes in recent Italian casuistry. Circumstantial, autopsy, and toxicological data were collected through a retrospective analysis performed between 2013 and 2017 in the Forensic Toxicology Unit of the University of Bologna. Cases of "DFC other than DFSA" and "Acute Intoxication" in which "psychoactive drugs" or "prescription drugs" or "licit drugs" were found in the blood samples of the victims were included in the study. Nine cases of DFC other than DFSA, and 11 cases of acute intoxication, were identified. Different categories of "licit" psychoactive drugs (e.g. hypnotics, antipsychotics, antidepressants, anticonvulsants) had been used to facilitate diverse types of crime (homicide, robberies, elder abuse, fatal poisoning) or acute intoxication (suicide, attempted suicide, accidental death). The circumstances of these cases, as well as toxicological findings in blood samples and other relevant forensic elements, are reported, summarized and discussed in this paper. The non-medical use of pharmaceuticals has been identified by recent forensic literature and the present study as a significant and growing phenomenon, and its implication in fatalities should be taken into consideration and accurately investigated through appropriate toxicological analysis. Our study presents an overview of the circumstances of non-medical use of prescription drugs, usually considered "safe drugs", and their involvement in cases of DFC, suicides and accidental intoxication. In order to estimate the real incidence of these medications in DFC and acute intoxication, and thus collect more analytical and contextual data, further studies are needed, along with effective cooperation among police officers, clinicians, forensic pathologists, and toxicologists.