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Context.—: As pharmacogenetic testing is incorporated into routine care, it is essential for laboratories to provide accurate and consistent results. Certified laboratories must successfully complete proficiency testing., Objectives.—: To understand and examine trends in participation and performance of laboratories participating in the College of American Pathologists pharmacogenetic proficiency testing surveys., Design.—: Results from College of American Pathologists pharmacogenetic proficiency testing challenges from 2012 through 2017 were reviewed for concordance with expected genotype and phenotype for each sample (intended responses)., Results.—: Laboratories correctly reported results for 96.7% to 100% of samples with no variants. Excluding CYP2D6, laboratories correctly detected and reported variant alleles for each gene (93.7%-99.2% correct). CYP2D6 showed lower concordance, with 83.1% of laboratories reporting the intended genotype across all samples; however, in many cases, the laboratories that did not report a variant allele did not test for that allele. Among laboratories reporting the intended genotype, most successfully reported the intended phenotype (85.9%-99.0%)., Conclusions.—: Although laboratories are generally performing well, there is room for additional improvement, particularly for challenging genes, such as CYP2D6. Efforts in the field of pharmacogenomics to recommend alleles that should be included in clinical tests, identify reference materials, and standardize translation from genotype to phenotype may address some of the remaining variability in results., (© 2020 College of American Pathologists.)

Background: Imatinib is one of the first-line therapies for chronic myeloid leukemia. Achieving a major molecular response early in treatment, as indicated by a BCR-ABL1 major international scale result of ≤0.1% within 6 months, is associated with better patient outcomes and is statistically associated with a trough imatinib concentration of approximately 1000 ng/mL. Adherence to therapy, drug resistance, drug-drug interactions, and pharmacokinetic/pharmacodynamic factors may hinder attaining this target. Therapeutic drug monitoring of imatinib is not currently standard-of-care, but may help to evaluate adherence and optimize treatment of patients with chronic myeloid leukemia. This study aimed to evaluate imatinib concentrations in real-world patient plasma samples to identify the proportion of imatinib-treated patients who achieved the therapeutic target of 1000 ng/mL., Methods: This was a retrospective, observational study that measured imatinib in residual plasma samples used for BCR-ABL1 tests (n = 1022) and analyzed clinician-ordered imatinib tests for therapeutic drug monitoring (n = 116). Imatinib was measured by competitive immunoassay. The frequency of imatinib concentrations achieving the therapeutic target was determined and correlated with BCR-ABL1 major international scale, age, and sex., Results: Seventy-two percent of patients tested for BCR-ABL1 may not have been prescribed or were not adherent to imatinib therapy. In the 29% of patients who did not achieve major molecular response, but had quantifiable imatinib concentrations, the therapeutic concentration was not met. For clinician-ordered imatinib tests, 45% of samples did not exceed the therapeutic target and 4% had potentially toxic plasma concentrations (>3000 ng/mL)., Conclusions: Therapeutic drug monitoring for imatinib may assist clinicians in the identification of patients who may not be adherent to therapy, display variable pharmacokinetics or pharmacodynamics, or may be experiencing toxicity or treatment failure.

Background: The psychoactive component of cannabis, tetrahydrocannabinol (THC), is one of many cannabinoids present in the plant. Since cannabinoids have extensive structural similarity, it is important to be aware of potential cross-reactivity with immunoassays designed to detect THC metabolite. This is especially important as cannabinoid products are increasingly marketed as legal supplements. The objective of this study was to assess the cross-reactivity of 2 commercial immunoassays designed to detect THC metabolite with 4 cannabinoids: cannabidiol, cannabinol, cannabichromene, and cannabigerol., Methods: Deidentified residual patient urine samples that tested negative for THC metabolite on initial testing were pooled and fortified with the above compounds to detect cross-reactivity. We next tested a range of CBN concentrations to determine what concentration of CBN was required to trigger a positive immunoassay result. Finally, we tested whether CBN has an additive effect with THC in the immunoassay by adding CBN to 21 samples weakly positive for THC by a mass spectrometry method but negative by the EMIT II Plus immunoassay., Results: Both the EMIT II Plus assay and the Microgenics MultiGent assay demonstrated cross-reactivity with CBN. For the EMIT II Plus assay, about 5-fold more CBN than THC metabolite was required to produce an assay signal equivalent to the cutoff concentration, and CBN displayed an additive effect with THC metabolite. For the Microgenics assay, 20-fold more CBN than THC metabolite was required to cross the cutoff concentration., Conclusions: These data may help guide the need for confirmatory testing when results of THC metabolite testing by immunoassay are inconsistent with expectations., (© American Association for Clinical Chemistry 2020. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Context.—: Urine drug testing is frequently ordered by health care providers. Immunoassays are widely used for drug testing, yet have potential limitations, including variable cross-reactivity. The last decade has seen worsening of a prescription drug abuse epidemic., Objective.—: To use data from a College of American Pathologists proficiency testing survey, Urine Drug Testing, Screening, to determine and summarize the characteristics, performance, and limitations of immunoassays., Design.—: Seven years of proficiency surveys were reviewed (2011-2017)., Results.—: Rapid growth was seen in participant volumes for specific immunoassays for synthetic opioids (eg, buprenorphine, fentanyl, oxycodone) and 3,4-methylenedioxymethamphetamine ("ecstasy"). Participant volumes remained high for immunoassays targeting less commonly abused drugs such as barbiturates and phencyclidine. For opiate immunoassays, the number of laboratories using a 2000 ng/mL positive cutoff remained stable, and an increasing number adopted a 100 ng/mL cutoff. Opiate and amphetamine immunoassays showed high variability in cross-reactivity for drugs other than the assay calibrator. Assays targeting a single drug or metabolite generally performed well on drug challenges., Conclusions.—: Survey results indicate strong clinical interest in urine drug testing and some adoption of new assays. However, urine drug testing availability does not parallel prevailing patterns of drug prescribing and abuse patterns. In particular, specific immunoassays for synthetic opioids and a lower positive cutoff for opiate immunoassays may be underused, whereas immunoassays for barbiturates, methadone, propoxyphene, and phencyclidine may be overused. Laboratories are encouraged to review their test menu, cutoffs, and assay performance and adjust their test offerings based on clinical needs and technical capabilities.

Pharmacogenetic testing increasingly is available from clinical and research laboratories. However, only a limited number of quality control and other reference materials currently are available for the complex rearrangements and rare variants that occur in the CYP2D6 gene. To address this need, the Division of Laboratory Systems, CDC-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Cell Repositories (Camden, NJ), has characterized 179 DNA samples derived from Coriell cell lines. Testing included the recharacterization of 137 genomic DNAs that were genotyped in previous Genetic Testing Reference Material Coordination Program studies and 42 additional samples that had not been characterized previously. DNA samples were distributed to volunteer testing laboratories for genotyping using a variety of commercially available and laboratory-developed tests. These publicly available samples will support the quality-assurance and quality-control programs of clinical laboratories performing CYP2D6 testing., (Copyright © 2019 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.)

Understanding levels of in utero drug exposure is important to properly customize the immediate, as well as ongoing, medical and social management needs of affected newborns. Here, we present the development of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection and quantification of 4 cannabinoid analytes in two neonatal matrices. The analytes targeted were Δ 9 -tetrahydrocannabinal (THC), 11-nor-9-carboxy-THC (THCA), 11-hydroxy-THC (11-OH-THC), and cannabinol (CBN). The matrices analyzed were umbilical cord tissue and meconium. A fifth analyte, cannabidiol (CBD), was also detected uniquely in meconium. Extracts were analyzed by LC-MS/MS in negative electrospray ionization mode. Paired meconium and umbilical cord samples (i.e., one specimen from each matrix collected from each single birth, n = 46 pairs) were tested to evaluate concentration and metabolite profiles. THCA was detected in all positive (containing one or more analytes) meconium samples (n = 32). CBN, THC, 11-OH-THC, and CBD were present in 57% (n = 26), 39% (n = 18), 24% (n = 11), and 20% (n = 9), respectively. Concentrations were lower in the umbilical cord samples for all analytes (i.e., 0.27-537 ng/g for meconium and 0.1-9 ng/g for umbilical cord). In umbilical cord THCA was also detected in all positive samples (n = 19) while THC, CBN, and 11-OH-THC were present in 24% (n = 11), 17% (n = 8), and 11% (n = 5), respectively. Testing neonatal matrices for cannabinoids could be used to support studies designed to detect newborns exposed to cannabis in utero , as well as provide data that could be examined for correlations with clinical and social outcomes., (© 2019 The Association for Mass Spectrometry: Applications to the Clinical Lab (MSACL). Published by Elsevier B.V. All rights reserved.)

In utero exposure to alcohol may adversely affect the development of the embryo or fetus and result in adverse outcomes known as fetal alcohol spectrum disorders (FASD) which encompass a range of physical, behavioral, and cognitive impairments in the newborn. Since maternal self-reports are often unreliable, biomarkers of gestational alcohol consumption are necessary for accurate identification of exposed newborns at risk. Ethyl-β-D-glucuronide (EtG) is a minor phase II metabolite of ethyl alcohol (ethanol), formed by enzymatic conjugation of ethanol with glucuronic acid in the liver. As a direct biomarker for alcohol, detection of EtG in neonatal biological matrices provides accurate identification of maternal alcohol consumption and fetal alcohol exposure during pregnancy. This chapter describes the quantitation of EtG in human umbilical cord tissue by liquid chromatography tandem mass spectrometry (LC-MS/MS).

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.

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.

In this study, the stability of 21 cocaine, opioid and benzodiazepine analytes in spiked meconium was investigated at three storage temperatures: 4°C, room temperature (RT), and 37°C (body temperature). The drugs/metabolites included were hydrocodone, hydromorphone, codeine, morphine, 6-acetylmorphine (6-AM), oxycodone, oxymorphone, cocaine, cocaethylene, benzoylecgonine, m-hydroxybenzoylecgonine, diazepam, oxazepam, temazepam, nordiazepam, chlordiazepoxide, lorazepam, alprazolam, alpha-hydroxyalprazolam, clonazepam, 7-aminoclonazepam, midazolam, alpha-hydroxymidazolam and zolpidem. Drug testing was performed using mass spectrometry methods that were validated for clinical use. After 2 weeks of storage, a substantial loss was observed in the concentrations of 7-aminoclonazepam (48.4% at 4°C and 71.5% at RT), and chlordiazepoxide (59.5% at RT). A slight decrease was observed in the concentrations of alprazolam (20.9% at 4°C), clonazepam (24.5% at 4°C), chlordiazepoxide (23.5% at 4°C), midazolam (20.8% at 4°C), nordiazepam (22.8% at RT), and alpha-hydroxyalprazolam (20.7% at 4°C). At 37°C, the concentrations of chlordiazepoxide, 7-aminoclonazepam, lorazepam, oxazepam, nordiazepam and temazepam decreased by 81.4%, 86.8%, 56.5%, 59.9%, 45.4% and 31.7%, respectively, after 2 weeks. 6-AM was observed to be unstable regardless of storage temperatures. For morphine, a 33.3% increase at 4°C and a 23.4% increase at RT were observed after 2 weeks, respectively, possibly due to 6-AM degradation, while no changes ≥20% were observed at 37°C. All other analytes were stable up to 2 weeks at all three storage temperatures (concentration changes <20%). The stability of select drug analytes in authentic clinical meconium specimens was consistent with that observed in spiked meconium. In conclusion, some drugs in meconium may not be stable for long periods of time. Sample storage conditions are an important consideration in the context of detection windows and interpreting drug-testing results in meconium. To the best of our knowledge, this is the first stability study of cocaine, opioids and benzodiazepines in meconium concerning the effects of storage temperatures., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objectives: The method described supports the detection of drugs and drug metabolites in the assessment of in utero drug exposure. The presented method employs liquid chromatography-tandem mass spectrometry (LC-MS/MS) as an alternative to a previously validated method using liquid chromatography-time-of-flight mass spectrometry (LC-TOF/MS). A reduction in required chromatographic time and consolidation from two injections to one injection per sample was desired to reduce turnaround time while maintaining the high specificity required., Design and Methods: Homogenized and extracted umbilical cord samples were analyzed using LC-TOF/MS and LC-MS/MS. The LC-MS/MS chromatographic method used a 3.5min gradient with an injection-to-injection time of 5min. Dynamic multiple reaction monitoring was utilized., Results: A 55% reduction in total analytical time was achieved by incorporating positive and negative mode acquisition in a single injection with the LC-MS/MS (5min cycle time) compared to the LC-TOF/MS method that required two total injections (one for positive mode, one for negative mode) and a combined ~11.5min cycle time. 514 patient samples were analyzed by both methods over 20 days. Of the 260 LC-TOF/MS negative samples, 259 were LC-MS/MS negative. Inter-assay imprecision conducted over 20days using the 50% and 150% QC samples yielded $&#95;amp&#95;$gt;97% qualitative acceptance and an average percent deviation from the target of 12% and 21%, respectively, using a single point calibration strategy., Conclusions: In comparison to the existing LC-TOF/MS method, the LC-MS/MS method delivered the required specificity in a single injection with a 55% reduction in instrument time. Use of a single-point calibration standard and eight representative internal standards provided adequate accuracy for the quantitative assessment of quality control results with qualitative reporting of patient results., (Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Buprenorphine (Suboxone, Zubsolv, Buprenex, Butrans, etc.) is an opioid drug that has been used to treat opioid dependence on an outpatient basis, and is also prescribed for managing moderate to severe pain. Pregnant women may be prescribed buprenorphine as part of a treatment plan for opioid addiction. This chapter quantitates buprenorphine and norbuprenorphine in meconium by liquid chromatography tandem mass spectrometry (LC-MS/MS).

Buprenorphine is an opioid drug that has been used to treat opioid dependence on an outpatient basis, and is also prescribed for managing moderate to severe pain. Some formulations of buprenorphine also contain naloxone to discourage misuse. The major metabolite of buprenorphine is norbuprenorphine. Both compounds are pharmacologically active and both are extensively metabolized to their glucuronide conjugates, which are also active metabolites. Direct quantitation of the glucuronide conjugates in conjunction with free buprenorphine, norbuprenorphine, and naloxone in urine can distinguish compliance with prescribed therapy from specimen adulteration intended to mimic compliance with prescribed buprenorphine. This chapter quantitates buprenorphine, norbuprenorphine, their glucuronide conjugates and naloxone directly in urine by liquid chromatography tandem mass spectrometry (LC-MS/MS). Urine is pretreated with formic acid and undergoes solid phase extraction (SPE) prior to analysis by LC-MS/MS.

Objectives: The major objective of this research was to propose a simplified approach for the evaluation of medication adherence in chronic pain management patients, using liquid chromatography time-of-flight (TOF) mass spectrometry, performed in parallel with select homogeneous enzyme immunoassays (HEIAs). We called it a "hybrid" approach to urine drug testing., Methods: The hybrid approach was defined based on anticipated positivity rates, availability of commercial reagents for HEIAs, and assay performance, particularly analytical sensitivity and specificity for drug(s) of interest. Subsequent to implementation of the hybrid approach, time to result was compared with that observed with other urine drug testing approaches., Results: Opioids, benzodiazepines, zolpidem, amphetamine-like stimulants, and methylphenidate metabolite were detected by TOF mass spectrometry to maximize specificity and sensitivity of these 37 drug analytes. Barbiturates, cannabinoid metabolite, carisoprodol, cocaine metabolite, ethyl glucuronide, methadone, phencyclidine, propoxyphene, and tramadol were detected by HEIAs that performed adequately and/or for which positivity rates were very low. Time to result was significantly reduced compared with the traditional approach., Conclusions: The hybrid approach to urine drug testing provides a simplified and analytically specific testing process that minimizes the need for secondary confirmation., (Copyright© by the American Society for Clinical Pathology.)

Depression is a psychiatric condition that affects about 120 million people worldwide and can interfere with independence and productivity in essentially all aspects of daily life. Depression is also associated with risk of self-harm, and ultimately suicide. Antidepressant medications are widely used to treat symptoms of depression. While there are several classes of antidepressants, therapeutic drug management (TDM) is most common for the tricyclic antidepressants (TCAs). TDM of TCAs is important due to wide inter-individual variability in pharmacokinetics, production of active metabolites, and a high risk of drug-drug interactions. In addition, TDM of some TCAs can be used to optimize dose, wherein concentration relationships are recognized for both therapeutic response and potentially life-threatening toxicity. In many clinical scenarios, TDM of TCAs is accomplished by currently available point of care or automated immunoassays that provide a "total" TCA concentration. However, these assays may not be adequately specific to meet the needs of all clinical scenarios, and hence, chromatographic separation and quantification of individual TCA parent drugs and active metabolites that may contribute to the "total" TCA concentration is sometimes required. This chapter describes an analytical method designed to detect and/or quantify clinically significant concentrations of nine TCAs (amitriptyline, nortriptyline, imipramine, desipramine, doxepin, nordoxepin, protriptyline, clomipramine, and norclomipramine) in serum or plasma, using ultra pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample preparation employs a rapid protein precipitation with 50:50 MeOH:acetonitrile, high speed centrifugation, and injection of 5 μL of supernatant onto the instrument, with a 5 min run-time.

Background: CYP2C19 variants have been demonstrated to play an important role in determining response to clopidogrel and outcomes while on clopidogrel therapy. Predicting patient response through pre-therapeutic genotyping may therefore guide selection of antiplatelet therapy., Methods: CYP2C19 genotypes were determined for 111 samples with the eSensor and compared with the Autogenomics expanded CYP2C19 panel, Luminex reagents, and bi-directional sequencing. Samples were obtained from the University of Chicago, ARUP Laboratories, and the Coriell repositories. Reproducibility studies were performed with 5 DNA samples with known CYP2C19 genotypes., Results: Complete concordance was observed for all samples and all platforms. DNA concentrations as low as 0.05 ng/μl may be used on the eSensor platform. There was 100% reproducibility observed with 2.5% incidence of invalid tests., Conclusions: The eSensor CYP2C19 genotyping assay is accurate and compares well with 2 current commercial platforms. With a relatively rapid turn-around time of ~4 h and a high rate (97.5%) of valid tests, the eSensor can be translated into clinical use to identify slow and rapid metabolizers of clopidogrel who may benefit from alternate therapy or unconventional dosing of clopidogrel. An observed limitation of the eSensor is a maximum capacity of 24 tests/run., (Copyright © 2011 Elsevier B.V. All rights reserved.)

In an exciting era where novel oral anticoagulants, such as the factor Xa and direct thrombin inhibitors, are beginning to emerge as therapeutic options, the vitamin K antagonists (VKAs) such as warfarin, which have been in clinical use for over half a century, will remain an important part of the therapeutic landscape for the foreseeable future. The optimal effectiveness and safety of the VKAs is limited by significant inter- and intra- patient variability in dose response. As such, routine laboratory monitoring with subsequent dose adjustment to achieve and maintain an international normalized ratio (INR) that falls within a narrow therapeutic range is necessary; even with frequent INR monitoring, time in therapeutic range of VKAs is generally <60% in usual care settings. Yet, personalized approaches to warfarin therapy, such as the routine incorporation of pharmacogenetic data into dose selection and adjustment, the selective use of prescribed doses of vitamin K for those patients with unstable INRs, and integration of patient self-testing /self-management, has the potential to improve the safety, efficacy and ease of use of warfarin. To date, no randomized trials have proven the benefits of routine pharmacogenetic testing for warfarin initiation; however, pivotal trials are ongoing. Through further investigative work, allowing these personalized strategies to realize their full potential, warfarin may remain a preferred therapeutic oral anticoagulant for years to come.

Discordant carbamazepine values as determined by two different immunoassays may be due to different cross-reactivities with the active metabolite carbamazepine 10, 11-epoxide and may cause confusion in interpreting carbamazepine serum levels. In this study, we compared carbamazepine values in samples containing carbamazepine and the epoxide metabolite, as determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and by two commercial carbamazepine immunoassays: the PETINIA and the ADVIA Centaur carbamazepine. Clinical specimens were used for the comparative studies wherein we determined carbamazepine concentrations using the PETINIA, ADVIA Centaur, and LC-MS/MS assays. We observed an excellent correlation between carbamazepine concentrations determined by the ADVIA Centaur and LC-MS/MS methods while carbamazepine values were overestimated using the PETINIA assay. When aliquots of drug-free serum were supplemented with clinically relevant concentrations of the carbamazepine epoxide metabolite, we observed negligible cross-reactivity of epoxide with the ADVIA Centaur assay but over 90% cross-reactivity with the PETINIA assay. We conclude that the ADVIA centaur assay accurately measures carbamazepine concentrations in plasma or serum and that the PETINIA assay significantly overestimates true carbamazepine concentration. Such discordance may cause confusion in interpreting serum carbamazepine levels., (© 2011 Wiley-Liss, Inc.)

We describe a single method for the detection and quantitation of 13 commonly prescribed benzodiazepines and metabolites: alpha-hydroxyalprazolam, alpha-hydroxyethylflurazepam, alpha-hydroxytriazolam, alprazolam, desalkylflurazepam, diazepam, lorazepam, midazolam, nordiazepam, oxazepam, temazepam, clonazepam and 7-aminoclonazepam in urine, serum, plasma, and meconium. The urine and meconium specimens undergo enzyme hydrolysis to convert the compounds of interest to their free form. All specimens are prepared for analysis using solid-phase extraction (SPE), analyzed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), and quantified using a three-point calibration curve. Deuterated analogs of all 13 analytes are included as internal standards. The instrument is operated in multiple reaction-monitoring (MRM) mode with an electrospray ionization (ESI) source in positive ionization mode. Urine and meconium specimens have matrix-matched calibrators and controls. The serum and plasma specimens are quantified using the urine calibrators but employing plasma-based controls. Oxazepam glucuronide is used as a hydrolysis control.

The results of meconium specimens and fortified samples screened for drugs of abuse by both enzyme multiplied immunoassay technique (EMIT((R) )II) and enzyme-linked immunosorbent assay (ELISA) methods were compared. The sample preparation for the ELISA screen was a simple buffer extraction versus a lengthy and more laborious sample preparation procedure for the EMIT II screen. The ELISA method was automated using a TECAN Genesis. The EMIT II analysis was automated with an Olympus AU400e. The opioid screen was calibrated with hydromorphone and the benzodiazepine screen was calibrated with clonazepam to maximize detection for these analytes. Previously validated gas chromatography-mass spectrometry (GC-MS), two-dimensional GC-MS, or liquid chromatography-tandem MS methods were used for confirmation. Results from the two techniques compared well. Agreement of the ELISA assay was greater than 90% when compared to EMIT II for all drug classes except barbiturates and benzodiazepines. ELISA appears to be more sensitive than EMIT II for the detection of amphetamines, methadone, propoxyphene, and cocaine. ELISA compared well to EMIT II for cannabinoids, opioids, and PCP. Specificity of the ELISA assay was slightly better for PCP and opioids. EMIT II appears to be more sensitive for the detection of barbiturates and benzodiazepines. The ELISA method reduced turnaround time by 50% compared to the EMIT II method.

Two versions of enzyme-linked immunosorbent assay (ELISA) kits designed for the detection of benzodiazepine drugs and metabolites (Immunalysis) were evaluated for use with meconium specimens. One was an older kit, and one was a new replacement kit developed for better detection of several commonly prescribed benzodiazepines and metabolites. The kits were evaluated by analyzing 68 patient specimens previously analyzed by liquid chromatography-tandem mass spectrometry and eight quality control samples. In addition to the recommended calibrator (oxazepam), clonazepam was evaluated as an alternate calibrator for the new kit. Detection and sensitivity for some analytes was improved using the new ELISA kit, but was reduced for others. The new kit using clonazepam as the calibrator provided the most sensitive assay for detection of the 11 benzodiazepines and metabolites reported here.

Copper is an essential element and, under conditions of overload, a toxicant. A dramatic example of copper toxicity is Wilson disease (WD), a treatable but often fatal condition that is difficult to diagnose and monitor. A method for direct measurement of free copper concentrations in serum or plasma ultrafiltrate by inductively coupled mass spectrometry was developed and validated to assist with diagnosis and monitoring WD. The method was shown to be accurate (94%-109% recoveries), linear (0.5-800 microg/dL [0.08-126 micromol/L]), and precise (coefficient of variation, < 15% over the analytic measurement range). A reference interval (0-10 microg/dL [0-1.6 micromol/L]) was determined parametrically with 137 healthy adult (20-59 years) blood donors. No statistically significant difference was observed in males (n = 69) vs females (n = 68). Free copper concentrations for patients diagnosed with WD were at least 6-fold greater than the upper limit of the reference interval before treatment but fell within the reference interval after treatment.

Neonates that are exposed to cannabinoids in utero may have characteristic physical and mental developmental problems throughout their lives. The early identification of exposed neonates allows early intervention and anticipation of potential problems. Testing meconium detects maternal marijuana use over the last four months of gestation, providing a better drug exposure marker than urine. However, the distribution of metabolites in meconium is not identical to urine and analytical methods must be adapted. Both the major urine metabolite, 11-nor-9-carboxy-Delta9-tetrahydrocannabinol (9-carboxy-THC), and a minor urine metabolite, 11-hydroxy-Delta9-tetrahydrocannabinol (11-hydroxy-THC), are common in meconium. Currently published methods to extract these two metabolites for instrumental analysis are time-consuming and laborious, often involving the preparation of two fractions. This study describes a simple solid-phase extraction method and an optimized hydrolysis method that allow the preparation and analysis of both metabolites in a single extract. The limit of detection by this extraction method was 5 ng/g for both metabolites with an analytical measurement range from 10 to 500 ng/g. The recovery at 100 ng/g was greater than 62% for both analytes. The analysis of 246 cannabinoid screen positive specimens illustrated the importance of including the 11-hydroxy-THC in a meconium marijuana confirmation: 16 specimens confirmed positive for 11-hydroxy-THC only, resulting in a 6.5% increase in the positivity rate compared to 9-carboxy-THC alone.

Introduction: Cytochrome p450 (CYP) 2C9 and 2C19 metabolize a wide range of therapeutically important drugs. Genetic polymorphisms in the CYP2C9 and CYP2C19 genes result in variations in drug response. To correlate the dose required for therapeutic drug efficacy with genotype, accurate and reliable methods for detecting single nucleotide polymorphisms (SNPs) of CYP2C9 and CYP2C19 are required., Study Design: We evaluated two technologies for genotyping CYP2C9 (*2 and *3 alleles) and CYP2C19 (*2 and *3 alleles). We developed a multiplexed flow cytometric assay based on the Luminex xMAP system and oligonucleotide-tagged Universal Array microspheres. The Luminex assay was compared with the eSensor DNA detection system, provided by Motorola Life Sciences. Genotypes determined by the two methods were confirmed by sequence analysis., Results: Of the 101 whole-genome amplified DNA samples genotyped by the Luminex method, 15 (14.8%) were heterozygous and 1 was homozygous for the CYP2C9*2 polymorphism. For the CYP2C9*3 polymorphism, 13 (12.9%) were heterozygous and 1 was homozygous. Two samples had the CYP2C9*2/*3 genotype. For CYP2C19*2, 17 (16.8%) of the samples were heterozygous and one was homozygous. The CYP2C19*3 polymorphism was not found. Genotypes determined by the Luminex assay were in complete concordance with the eSensor SNP assay results. A dilution study showed that 1.5 ng of nucleic acid was adequate for PCR and subsequent detection of SNPs by the Luminex assay. The within run and between run coefficients of variance (CVs) for allelic ratios determined by the Luminex procedure were found to be