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Hentschel A, Piontek G, Dahlmann R, Findeisen P, Sakson R, Carbow P, Renné T, Reinders Y, Sickmann A. Highly sensitive therapeutic drug monitoring of infliximab in serum by targeted mass spectrometry in comparison to ELISA data. Clin Proteomics 2024; 21:16. [PMID: 38424496 PMCID: PMC10905900 DOI: 10.1186/s12014-024-09464-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/12/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND Presently, antibody concentration measurements for patients undergoing treatment are predominantly determined by ELISA, which still comes with known disadvantages. Therefore, our aim was to establish a targeted mass-spectrometric assay enabling the reproducible absolute quantification of peptides from the hypervariable and interaction regions of infliximab. METHODS Peptides of infliximab were measured post-trypsin digestion and subsequent separation on a Vanquish Horizon UHPLC coupled to a TSQ Altis Triple-Quad mass spectrometer. Normalization and absolute quantification were conducted using stable isotope-synthesized peptides. Calibration curves covering a range of 0.25-50 µg/ml were employed for quantitation. RESULTS We demonstrated the substantial influence of peptide selection, choice of hydrolase for digestion, and digestion time on absolute peptide yield (28-44% for peptide 1 and 64-97% for peptide 2). Furthermore, we showed that the generated calibration curves for absolute quantification were highly reproducible and robust (LLOQ1 0.72 µg/ml and LLOQ2 1.00 µg/ml) over several months. In comparison to ELISA values, the absolute values obtained by mass spectrometry often yielded lower results for both targeted peptides. CONCLUSIONS In this study, a semi-automated workflow was employed and tested with 8 patients and corresponding replicates (n = 3-4). We demonstrated the robust implementation of calibration curves for the absolute quantification of infliximab in patient samples, with coefficients of variation ranging from 0.5 to 9%. Taken together, we have developed a platform enabling the rapid (2 days of sample preparation and 30 min of measurement time per sample) and robust quantification of Infliximab antibody concentration in patients. The use of mass spectrometry also facilitates the straightforward expansion of the method to include additional antibody peptides.
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Affiliation(s)
- Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Gina Piontek
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Rob Dahlmann
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | | | - Roman Sakson
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Phil Carbow
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Thomas Renné
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Irish Centre for Vascular Biology, School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
- Center for Thrombosis and Hemostasis (CTH), Johannes Gutenberg University Medical Center, Mainz, Germany
| | - Yvonne Reinders
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany.
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Bochum, Germany.
- Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, United Kingdom.
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Sakai N, Kamimura K, Terai S. Repurposable Drugs for Immunotherapy and Strategies to Find Candidate Drugs. Pharmaceutics 2023; 15:2190. [PMID: 37765160 PMCID: PMC10536625 DOI: 10.3390/pharmaceutics15092190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/20/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
Conventional drug discovery involves significant steps, time, and expenses; therefore, novel methods for drug discovery remain unmet, particularly for patients with intractable diseases. For this purpose, the drug repurposing method has been recently used to search for new therapeutic agents. Repurposed drugs are mostly previously approved drugs, which were carefully tested for their efficacy for other diseases and had their safety for the human body confirmed following careful pre-clinical trials, clinical trials, and post-marketing surveillance. Therefore, using these approved drugs for other diseases that cannot be treated using conventional therapeutic methods could save time and economic costs for testing their clinical applicability. In this review, we have summarized the methods for identifying repurposable drugs focusing on immunotherapy.
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Affiliation(s)
- Norihiro Sakai
- Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Aasahimachi-Dori, Chuo-Ku, Niigata 951-8510, Japan; (N.S.); (S.T.)
| | - Kenya Kamimura
- Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Aasahimachi-Dori, Chuo-Ku, Niigata 951-8510, Japan; (N.S.); (S.T.)
- Department of General Medicine, Niigata University School of Medicine, 1-757, Aasahimachi-Dori, Chuo-Ku, Niigata 951-8510, Japan
| | - Shuji Terai
- Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, 1-757, Aasahimachi-Dori, Chuo-Ku, Niigata 951-8510, Japan; (N.S.); (S.T.)
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3
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Jiang R, Zhang D, Zhao Z, Mei S. Simultaneous determination of 24 antiepileptic drugs and their active metabolites in human plasma by UHPLC-MS/MS. J Pharm Biomed Anal 2023; 232:115437. [PMID: 37146498 DOI: 10.1016/j.jpba.2023.115437] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/02/2023] [Accepted: 04/30/2023] [Indexed: 05/07/2023]
Abstract
Antiepileptic drugs (AEDs) have narrow therapeutic ranges with large individual variability. Routine therapeutic drug monitoring of AEDs was useful for dose optimization, but the common immunoassays could not meet the detection requirements of AEDs, especially for new generation AEDs. The aim of this study was to validate an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for simultaneously quantification of 24 AEDs and their active metabolites in human plasma and comparison with a chemiluminescent immunoassay (Simens ADVIA Centaur). The method validation was performed according to FDA and EMEA guidelines. A one-step protein precipitation by acetonitrile followed a five-fold dilution was performed for sample pretreatment. A 5.2 min gradient separation by methanol and 10 mM ammonium acetate was used for separation at 0.6 mL/min under 45 °C. Both positive and negative electrospray ionization were used. Isotopic internal standard was used for all analytes. The inter-day (36 days) accuracy and precision of quality control samples were - 1.07-13.69% and < 6.70% for all analytes. The stability was acceptable for all analytes under routine storing conditions. A total of 436 valproic acid, 118 carbamazepine, and 65 phenobarbital samples were determined twice by each of the UHPLC-MS/MS and immunoassay. Evaluated by Bland-Altman plot, the mean overestimation of the immunoassay compared to UHPLC-MS/MS was 16.5% for valproic acid, 5.6% for carbamazepine, and 40.3% for phenobarbital.
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Affiliation(s)
- Ruiqi Jiang
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, 119 Nansihuan West Road, Fengtai District, Beijing 100070, PR China; Department of Clinical Pharmacology, College of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, PR China
| | - Dongjie Zhang
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, 119 Nansihuan West Road, Fengtai District, Beijing 100070, PR China
| | - Zhigang Zhao
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, 119 Nansihuan West Road, Fengtai District, Beijing 100070, PR China; Department of Clinical Pharmacology, College of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, PR China.
| | - Shenghui Mei
- Department of Pharmacy, Beijing Tiantan Hospital, Capital Medical University, 119 Nansihuan West Road, Fengtai District, Beijing 100070, PR China; Department of Clinical Pharmacology, College of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, PR China.
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4
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Krasowski MD, Long TA, Snozek CLH, Dizon A, Magnani B, Melanson SEF. Therapeutic Drug Monitoring of Second- and Third-Generation Antiepileptic Drugs: Insights From a College of American Pathologists Proficiency Testing Survey. Arch Pathol Lab Med 2021; 145:1485-1491. [PMID: 33720327 DOI: 10.5858/arpa.2020-0562-cp] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2020] [Indexed: 11/06/2022]
Abstract
CONTEXT.— Therapeutic drug monitoring has traditionally been widely used for first-generation antiepileptic drugs (AEDs) such as carbamazepine and phenytoin. The last 2 decades have seen the introduction of second- and third-generation AEDs (eg, lamotrigine, levetiracetam, and topiramate) into clinical practice. OBJECTIVE.— To use data from the College of American Pathologists Therapeutic Drug Monitoring, Extended proficiency testing survey to determine the performance of assays used for therapeutic drug monitoring of newer AEDs, including comparison of enzyme immunoassay and chromatographic techniques. DESIGN.— Six years of proficiency testing surveys were reviewed (2013-2018). RESULTS.— Steady growth was seen in participant volumes for newer AEDs. The analytical performance of automated enzyme immunoassays for lamotrigine, levetiracetam, and topiramate was similar to that of chromatographic methods, consistent with published literature using patient samples for comparisons. The majority of participating laboratories now use enzyme immunoassays to measure levetiracetam. CONCLUSIONS.— Survey results reflect steadily growing interest in therapeutic drug monitoring of newer AEDs. The increasing availability of robust immunoassays for new AEDs should facilitate their clinical utility, especially for clinical laboratories that do not perform chromatographic assays for therapeutic drug monitoring.
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Affiliation(s)
- Matthew D Krasowski
- From the Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City (Krasowski)
| | - Thomas A Long
- The Department of Biostatistics (Long), College of American Pathologists, Northfield, Illinois
| | - Christine L H Snozek
- The Department of Laboratory Medicine and Pathology, Mayo Clinic in Arizona, Scottsdale (Snozek)
| | - Annabel Dizon
- The Proficiency Testing Division (Dizon), College of American Pathologists, Northfield, Illinois
| | - Barbarajean Magnani
- The Department of Pathology and Laboratory Medicine, Tufts Medical Center, and the Department of Anatomic and Clinical Pathology, Tufts University of Medicine, Boston, Massachusetts (Magnani)
| | - Stacy E F Melanson
- The Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts (Melanson)
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Beyaz Ş, Akdeniz N, Yılmaz A, Demir S, Öztop N, Çolakoğlu B, Büyüköztürk S, Deniz G, Gelincik A. Diagnostic workup including CD203c-based basophil activation test in immediate hypersensitivity due to metronidazole and ornidazole and evaluation of cross-reactivity in between. Allergy 2021; 76:842-852. [PMID: 32761620 DOI: 10.1111/all.14542] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/08/2020] [Accepted: 07/25/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Little is known about the diagnostic approaches for immediate hypersensitivity reactions (IHRs) due to 5-nitroimidazole antibiotics. The aim was to evaluate the usefulness of in vivo tests and basophil activation test (BAT) for the diagnosis of IHRs due to metronidazole and ornidazole and to determine possible cross-reactivity in between. METHODS Forty-nine patients with a clear history of IHRs due to these drugs and 20 healthy subjects who were known to tolerate these drugs were included. Skin tests (STs) and single-blind placebo-controlled drug provocation tests (SBPCDPTs) were performed with both drugs whereas BAT was applied only with the culprit drug. RESULTS The most and least common reaction types were urticaria/angioedema (34.7%) and anaphylaxis (14.3%), respectively. SBPCDPTs were positive in 15 out of 47 patients, and only 7 had positive STs. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of STs for metronidazole/ornidazole were 33.3%/16.6%, 94.2%/97.3%, 60%/50%, and 84.6%/88.1%, respectively. BAT was positive in 12 out of 15 patients and negative in 10 control subjects, giving a sensitivity rate of 71.4% (CI, 29.0%-96.3%) for metronidazole and 83.3% (CI, 35.8%-99.5%) for ornidazole. The optimal concentration of both drugs for BAT was determined as 5 mg/mL. No cross-reactivity among two drugs was observed according to in vivo tests. CONCLUSIONS Our study showed that SBPCDPT and BAT are both useful diagnostic tools for IHRs due to 5-nitroimidazole antibiotics and can be used as supplementary to each other. No cross-reactivity between metronidazole and ornidazole in IHRs exists.
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Affiliation(s)
- Şengül Beyaz
- Division of Immunology and Allergic Diseases Department of Internal Medicine Istanbul Faculty of Medicine Istanbul University Istanbul Turkey
| | - Nilgün Akdeniz
- Department of Immunology Aziz Sancar Institute of Experimental MedicineIstanbul University Istanbul Turkey
| | - Abdullah Yılmaz
- Department of Immunology Aziz Sancar Institute of Experimental MedicineIstanbul University Istanbul Turkey
| | - Semra Demir
- Division of Immunology and Allergic Diseases Department of Internal Medicine Istanbul Faculty of Medicine Istanbul University Istanbul Turkey
| | - Nida Öztop
- Division of Immunology and Allergic Diseases Department of Internal Medicine Istanbul Faculty of Medicine Istanbul University Istanbul Turkey
| | - Bahauddin Çolakoğlu
- Division of Immunology and Allergic Diseases Department of Internal Medicine Istanbul Faculty of Medicine Istanbul University Istanbul Turkey
| | - Suna Büyüköztürk
- Division of Immunology and Allergic Diseases Department of Internal Medicine Istanbul Faculty of Medicine Istanbul University Istanbul Turkey
| | - Günnur Deniz
- Department of Immunology Aziz Sancar Institute of Experimental MedicineIstanbul University Istanbul Turkey
| | - Aslı Gelincik
- Division of Immunology and Allergic Diseases Department of Internal Medicine Istanbul Faculty of Medicine Istanbul University Istanbul Turkey
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6
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Fayyaz S, Kreiling R, Sauer UG. Application of grouping and read-across for the evaluation of parabens of different chain lengths with a particular focus on endocrine properties. Arch Toxicol 2021; 95:853-881. [PMID: 33459807 PMCID: PMC7904550 DOI: 10.1007/s00204-020-02967-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/22/2020] [Indexed: 11/29/2022]
Abstract
This article presents the outcomes of higher-tier repeated-dose toxicity studies and developmental and reproductive toxicity (DART) studies using Wistar rats requested for methyl paraben and propyl paraben under the European Union chemicals legislation. All studies revealed no-observed adverse effects (NOAELs) at 1000 mg/kg body weight/day. These findings (absence of effects) were then used to interpolate the hazard profile for ethyl paraben, further considering available data for butyl paraben. The underlying read-across hypothesis (all shorter-chained linear n-alkyl parabens are a ‘category’ based on very high structural similarity and are transformed to a common compound) was confirmed by similarity calculations and comparative in vivo toxicokinetics screening studies for methyl paraben, ethyl paraben, propyl paraben and butyl paraben. All four parabens were rapidly taken up systemically following oral gavage administration to rats, metabolised to p-hydroxybenzoic acid, and rapidly eliminated (parabens within one hour; p-hydroxybenzoic acid within 4–8 h). Accordingly, for ethyl paraben, the NOAELs for repeated-dose toxicity and DART were interpolated to be 1000 mg/kg body weight/day. Finally, all evidence was evaluated to address concerns expressed in the literature that parabens might be endocrine disruptors. This evaluation showed that the higher-tier studies do not provide any indication for any endocrine disrupting property. This is the first time that a comprehensive dataset from higher-tier in vivo studies following internationally agreed test protocols has become available for shorter-chained linear n-alkyl parabens. Consistently, the dataset shows that these parabens are devoid of repeated-dose toxicity and do not possess any DART or endocrine disrupting properties.
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Affiliation(s)
- Susann Fayyaz
- Clariant Produkte (Deutschland) GmbH, Am Unisyspark 1, 65843, Sulzbach, Germany
| | - Reinhard Kreiling
- Clariant Produkte (Deutschland) GmbH, Am Unisyspark 1, 65843, Sulzbach, Germany.
| | - Ursula G Sauer
- Scientific Consultancy-Animal Welfare, Neubiberg, Germany
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7
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Davis DE, Sherrod SD, Gant-Branum RL, Colby JM, McLean JA. Targeted Strategy to Analyze Antiepileptic Drugs in Human Serum by LC-MS/MS and LC-Ion Mobility-MS. Anal Chem 2020; 92:14648-14656. [PMID: 33047601 PMCID: PMC10103591 DOI: 10.1021/acs.analchem.0c03172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Routine small-molecule analysis is challenging owing to the need for high selectivity and/or low limits of quantification. This work reports a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify 14 antiepileptic drugs (AEDs) in human serum. For the optimized LC-MS/MS method described herein, we applied the guidelines outlined in the Clinical and Laboratory Standards Institute (CLSI) LC-MS C62-A document and the U.S. Food and Drug Administration (FDA) Bioanalytical Method Validation Guidance for Industry to evaluate the quality of the assay. In these studies, AED linearity, analyte recovery, matrix effects, precision, and accuracy were assessed. Using liquid chromatography-drift tube ion mobility-mass spectrometry (LC-DTIM-MS), a qualitative method was also used to increase confidence in AED identification using accurate mass and collision cross section (CCS) measurements. The LC-DTIM-MS method was also used to assess the ability of drift tube CCS measurements to aid in the separation and identification of AED structural isomers and other AEDs. These data show that another dimension of information, namely CCS measurements, provides an orthogonal dimension of structural information needed for AED analysis. Multiplexed AED measurements using LC-MS/MS and LC-DTIM-MS have the potential to enable better optimization of dosing owing to the high precision capabilities available in these types of analytical studies. Taken together, these data also show the ability to increase confidence in small-molecule identification and quantification using these analytical technologies.
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Affiliation(s)
- Don E Davis
- Center for Innovative Technology, Department of Chemistry, Institute of Chemical Biology, Institute for Integrative Biosystems Research and Education, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Stacy D Sherrod
- Center for Innovative Technology, Department of Chemistry, Institute of Chemical Biology, Institute for Integrative Biosystems Research and Education, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Randi L Gant-Branum
- Center for Innovative Technology, Department of Chemistry, Institute of Chemical Biology, Institute for Integrative Biosystems Research and Education, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Jennifer M Colby
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37235, United States
| | - John A McLean
- Center for Innovative Technology, Department of Chemistry, Institute of Chemical Biology, Institute for Integrative Biosystems Research and Education, Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, United States
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Kingery JM, Radke JB, Maakestad J, Krasowski MD. Data on hydroxychloroquine interference with urine laboratory testing. Data Brief 2019; 27:104781. [PMID: 31799344 PMCID: PMC6881646 DOI: 10.1016/j.dib.2019.104781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 11/01/2019] [Indexed: 11/16/2022] Open
Abstract
Hydroxychloroquine is a medication used to treat rheumatoid arthritis, systemic lupus erythematosus, and other autoimmune disorders. Previous studies have shown that hydroxychloroquine and the structurally related drug chloroquine have the potential to interfere with some common urine chemistry tests, especially at high concentrations. In the related research article, we observed suspected interference with urine drug of abuse testing in a patient who ingested approximately 12 g of hydroxychloroquine in an acute overdose, with urine hydroxychloroquine concentrations exceeding 500 mg/L. This case prompted a more detailed investigation of the effects of hydroxychloroquine spiked into pooled de-identified urine specimens from a hospital clinical laboratory. The data in this article provides the raw data for 24 urine assays that were investigated. The analyzed data is provided in the tables included in this article. The dataset reported is related to the research article entitled “Diagnostic Pitfalls and Laboratory Test Interference After Hydroxychloroquine Intoxication: A Case Report” [1].
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Affiliation(s)
- Jennie M Kingery
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Joshua B Radke
- Department of Emergency Medicine, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Jon Maakestad
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Matthew D Krasowski
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
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9
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Sauer UG, Kreiling R. The Grouping and Assessment Strategy for Organic Pigments (GRAPE): Scientific evidence to facilitate regulatory decision-making. Regul Toxicol Pharmacol 2019; 109:104501. [PMID: 31629781 DOI: 10.1016/j.yrtph.2019.104501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/09/2019] [Accepted: 10/15/2019] [Indexed: 10/25/2022]
Abstract
This article presents the Grouping and Assessment Strategy for Organic Pigments (GRAPE). GRAPE is driven by the hypotheses that low (bio)dissolution and low permeability indicate absence of systemic bioavailability and hence no systemic toxicity potential upon oral exposure, and, for inhalation exposure, that low (bio)dissolution (and absence of surface reactivity, dispersibility and in vitro effects) indicate that the organic pigment is a 'poorly soluble particle without intrinsic toxicity potential'. In GRAPE Tier 1, (bio)solubility and (bio)dissolution are assessed, and in Tier 2, in vitro Caco-2 permeability and in vitro alveolar macrophage activation. Thereafter, organic pigments are grouped by common properties (further considering structural similarity depending on the regulatory requirements). In Tier 3, absence of systemic bioavailability is verified by limited in vivo screening (rat 28-day oral and 5-day inhalation toxicity studies). If Tier 3 confirms no (or only very low) systemic bioavailability, all higher-tier endpoint-specific animal testing is scientifically not-relevant. Application of the GRAPE can serve to reduce animal testing needs for all but few representative organic pigments within a group. GRAPE stands in line with the EU REACH Regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals). An ongoing research project aims at establishing a proof-of-concept of the GRAPE.
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Radke JB, Kingery JM, Maakestad J, Krasowski MD. Diagnostic pitfalls and laboratory test interference after hydroxychloroquine intoxication: A case report. Toxicol Rep 2019; 6:1040-1046. [PMID: 31673506 PMCID: PMC6816131 DOI: 10.1016/j.toxrep.2019.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 10/01/2019] [Accepted: 10/04/2019] [Indexed: 02/03/2023] Open
Abstract
Hydroxychloroquine overdose can cause hypokalemia. Hydroxychloroquine overdose can result in electrocardiographic abnormalities. Hydroxychloroquine can interfere with urine chemistry and drug screening assays. Urine concentrations of hydroxychloroquine can exceed 500 mg/L in acute overdose.
Hydroxychloroquine is a medication used to treat autoimmune conditions. Overdoses of hydroxychloroquine are uncommon, with most recommendations on monitoring drawing from experience with more common overdoses of the related drug chloroquine. We present a case of an adolescent with intentional overdose of approximately 12 g of hydroxychloroquine. The prominent clinical features were hypokalemia and widened QRS and QT intervals on the electrocardiogram. Therapy included epinephrine by intravenous drip and bicarbonate infusions along with supportive care and cardiac monitoring. The patient recovered without sequelae. Urine drug testing showed an absorbance alarm for one of the components of the institution drug of abuse screening panel, an oxycodone screen using an enzyme immunoassay. Analysis of two urine specimens collected during the hospitalization revealed hydroxychloroquine concentrations of greater than 500 mg/L (approximately 7.5 h after ingestion) and 130 mg/L (approximately 14 h after ingestion). Only the urine with greater than 500 mg/L hydroxychloroquine produced absorbance alarms on the drug of abuse testing. We separately analyzed the impact on 24 urine assays of varying concentrations of hydroxychloroquine spiked into de-identified pooled urine samples. For 6 of the assays (buprenorphine, cotinine, oxycodone, and tetrahydrocannabinol qualitative drug screens; microalbumin and urine myoglobin quantitative assays), hydroxychloroquine produced significant bias and/or instrument alarms. Overall, our study demonstrates that urine concentrations of hydroxychloroquine can reach very high concentrations (exceeding 500 mg/L) following overdose, with the potential to interfere with a range of urine assays including drug of abuse screening and microalbumin. Similar to previous reports, hydroxychloroquine overdose can produce hypokalemia and electrocardiographic abnormalities.
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Affiliation(s)
- Joshua B Radke
- Department of Emergency Medicine, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Jennie M Kingery
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Jon Maakestad
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
| | - Matthew D Krasowski
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA, 52242, USA
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11
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Skaugen JM, Scoccimarro A, Pizon AF, Rymer JA, Giannoutsos S, Ekins S, Krasowski MD, Tamama K. Novel ketamine analogues cause a false positive phencyclidine immunoassay. Ann Clin Biochem 2019; 56:598-607. [DOI: 10.1177/0004563219858125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background Immunoassays are commonly used to test for drugs of abuse in patients in a variety of settings. The increasing prevalence of ‘designer’ drugs causes difficulties for the toxicology laboratory and may result in unexpected false positives and identification of unfamiliar compounds. Within the past decade, there have been a variety of ketamine and phencyclidine analogues identified, particularly as drugs of abuse. Method We present a case of intoxication with a novel ketamine analogue, deschloro-N-ethyl-ketamine, causing a false positive phencyclidine immunoassay. Additionally, we performed spiking studies and 2D molecular similarity calculations for deschloro-N-ethyl-ketamine, ketamine and three other analogues on the Siemens Viva-E EMIT-II phencyclidine assay to assess their cross-reactivity. Results Four of the tested compounds (deschloro-N-ethyl-ketamine, 3-methoxy-phencyclidine, 3-methoxy-eticyclidine and methoxetamine) cause false positive phencyclidine immunoassay results, while ketamine gives a negative result. The cross-reactivity data are in accord with the similarity calculations of these molecules, further validating the ability of 2D molecular similarity analysis to predict the molecular cross-reactivity in immunoassays. Conclusions The cross-reactivity data of phencyclidine and ketamine analogues presented in this study could help toxicology laboratories and clinicians in evaluating unexpected results, particularly when novel PCP and ketamine analogues are being considered.
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Affiliation(s)
- John M Skaugen
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USA
| | - Anthony Scoccimarro
- Division of Medical Toxicology, Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Anthony F Pizon
- Division of Medical Toxicology, Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jacqueline A Rymer
- Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USA
| | - Spiros Giannoutsos
- Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USA
| | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina, USA
| | - Matthew D Krasowski
- Department of Pathology, University of Iowa Hospital and Clinics, Iowa City, IA, USA
| | - Kenichi Tamama
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Clinical Laboratory, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
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Rosenfeld B, Budescu DV, Han Y, Foellmi M, Kirsh KL, Passik SD. Does the perceived accuracy of urine drug testing impact clinical decision-making? Subst Abus 2019; 41:85-92. [PMID: 31206353 DOI: 10.1080/08897077.2019.1621239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background: Urine drug testing techniques have different rates of false-positive and false-negative test results. However, clinicians may have highly varying perceptions of test accuracy and may compensate for perceived inaccuracy by incorporating other factors into their interpretation of observed test results. Thus, there is the potential for adverse consequences from decisions based on inaccurate test results or interpretation. Methods: We surveyed 466 members of the American Society of Addiction Medicine to examine clinicians' perceptions of the accuracy of 2 types of urine drug tests, immunoassay (IA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the extent to which behavioral and demographic factors influence the interpretation of test results. Participants read 4 brief vignettes describing positive and negative test results in hypothetical patients who differed along several dimensions (gender, age, race/ethnicity, comorbid mental disorder, court-ordered versus voluntary status, treatment compliance). Outcome variables include likelihood of renewed drug use, likelihood of test error, whether to request additional testing, and whether to report the violation to a probation officer. Results: The strongest predictor of study outcomes was treatment compliance (consistent versus inconsistent attendance), as this was the only independent variable to generate effect sizes of medium strength. Significant effect sizes were also found for type of test used (IA versus LC-MS/MS), legal status (court-mandated versus voluntary), presence of a comorbid mental disorder, treatment history, and race, although effect sizes for these variables were small and less consistently observed. Conclusions: These results highlight the potential for error in clinician judgments about urine drug testing. Not only were participants likely to underestimate the accuracy of "confirmatory" LC-MS/MS testing, but vignettes suggested that a number of historical and demographic factors may influence interpretation of test results.
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Affiliation(s)
- Barry Rosenfeld
- Department of Psychology, Fordham University, Bronx, New York, USA
| | - David V Budescu
- Department of Psychology, Fordham University, Bronx, New York, USA
| | - Ying Han
- Department of Psychology, Fordham University, Bronx, New York, USA
| | - Melodie Foellmi
- Department of Psychology, Fordham University, Bronx, New York, USA
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Accidental intoxications in toddlers: lack of cross-reactivity of vilazodone and its urinary metabolite M17 with drug of abuse screening immunoassays. BMC Clin Pathol 2019; 19:2. [PMID: 30820187 PMCID: PMC6379996 DOI: 10.1186/s12907-019-0084-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 02/07/2019] [Indexed: 12/22/2022] Open
Abstract
Background Vilazodone is an FDA approved medication used to treat major depressive disorder. The authors describe two cases of accidental vilazodone exposure in toddlers who presented with symptoms similar to amphetamine exposure and also with unexplained positive amphetamine urine immunoassay drug screens. Given a lack of published data on cross-reactivity of vilazodone and its metabolites with drug of abuse screening tests, the authors investigated drug of abuse immunoassay cross-reactivity of vilazodone and metabolites using computational and empirical approaches. Methods To ascertain the likelihood that vilazodone would cross-react with drug of abuse screening immunoassays, the authors assessed the two-dimensional (2D) similarity of the vilazodone parent molecule and known metabolites to an array of antigenic targets for urine immunoassay drug screens. To facilitate studies of the commercially unavailable M17 metabolite, it was prepared synthetically through a novel scheme. Urine and serum were spiked with vilazodone and M17 into urine (200–100,000 ng/mL) and serum (20–2000 ng/mL) samples and tested for cross-reactivity. Results Computational analysis using 2D similarity showed that vilazodone and metabolites have generally low similarity to antigenic targets of common drug of abuse screening immunoassays, predicting weak or no cross-reactivity. The M17 metabolite had 2D similarity to amphetamines and tricyclic antidepressants in a range similar to some other compounds exhibiting weak cross-reactivity on these immunoassays. Cross-reactivity testing was therefore performed on two different urine amphetamines immunoassays and a serum tricyclic antidepressant immunoassay. However, actual testing of cross reactivity for vilazodone and the M17 metabolite did not detect cross-reactivity for any urine amphetamines screen at concentrations up to 100,000 ng/mL and for a serum tricyclic antidepressants assays at concentrations up to 2000 ng/mL. Conclusion While the vilazodone metabolite M17 has weak 2D structural similarity to amphetamines and tricyclic antidepressants, the current study did not demonstrate any experimental cross-reactivity with two different urine amphetamines immunoassays and a serum tricyclic antidepressant immunoassay. Vilazodone ingestions in young children present a diagnostic challenge in their similarity to amphetamine ingestions and the lack of routine laboratory tests for vilazodone. Further work is needed to understand the metabolic profile for vilazodone in children versus adults. Electronic supplementary material The online version of this article (10.1186/s12907-019-0084-9) contains supplementary material, which is available to authorized users.
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Reschly-Krasowski JM, Krasowski MD. A Difficult Challenge for the Clinical Laboratory: Accessing and Interpreting Manufacturer Cross-Reactivity Data for Immunoassays Used in Urine Drug Testing. Acad Pathol 2018; 5:2374289518811797. [PMID: 30480089 PMCID: PMC6249658 DOI: 10.1177/2374289518811797] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/05/2018] [Accepted: 10/15/2018] [Indexed: 11/15/2022] Open
Abstract
Urine drug testing by immunoassay is widely used to detect nonmedical drug use and to monitor patients prescribed controlled substances. A key attribute of urine drug testing immunoassays is cross-reactivity, namely the response of various compounds compared to the target of the assay. In this report, we analyzed the variability in how manufacturer cross-reactivity data are summarized in package inserts for commercially available amphetamines, benzodiazepines, and opiates immunoassays, 3 broad drug classes commonly included in routine drug testing panels. Specifically, we determined the number of compounds tested for cross-reactivity, manner in which cross-reactivity is measured, concentration units used, how often compounds known to be cross-reactive with marketed urine drug testing immunoassays prior to 2010 were tested, availability of the package insert online, and how often cross-reactivity on "designer drugs" was found in the package inserts. There was wide variability in the number of compounds tested (both positive and negative), with the highest number of tested compounds generally found in point-of-care urine drug testing applications. Most package inserts used ng/mL as the concentration units and expressed cross-reactivity in terms of equivalent concentrations to the assay calibrator. Approximately 50% of package inserts were directly available online. Cross-reactivity data were sparse with respect to "off-target" drugs known to be cross-reactive prior to 2010 (an example being quinolone antibiotics and opiates immunoassays) and designer drugs. The present study indicates lack of consistency in cross-reactivity information in package inserts, complicating the interpretation of urine drug testing results. We use 3 example clinical cases to illustrate practical challenges accessing and interpreting cross-reactivity data.
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Affiliation(s)
| | - Matthew D Krasowski
- Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA, USA
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15
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Ünal D, Demir S, Gelincik A, Olgaç M, Coşkun R, Çolakoğlu B, Büyüköztürk S. Diagnostic Value of Oral Challenge Testing in the Diagnosis of Macrolide Hypersensitivity. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2018; 6:521-527. [DOI: 10.1016/j.jaip.2017.06.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/30/2017] [Accepted: 06/30/2017] [Indexed: 01/25/2023]
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Cross-reactivity of selected benzofurans with commercial amphetamine and ecstasy immunoassays in urine. Bioanalysis 2017; 9:1771-1785. [DOI: 10.4155/bio-2017-0191] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Aim: The aim of this study was to perform a cross-reactivity investigation of six benzofurans with immunoassays (IAs) screening tests for amphetamines and ecstasy in urine samples. Methods: The following benzofuranes were investigated: 5-(2-Methylaminopropyl)Benzofuran (5-MAPB), 5-(2-methylaminopropyl)-2,3-dihydrobenzofuran (5-MAPDB), 5-(2-Aminopropyl)-Benzofuran (5-APB), 5-(2-Aminopropyl)-2,3-dihydrobenzofuran (5-APDB), 5-(2-Ethylaminopropyl)Benzofuran (5-EAPB) and 5-(2-Aminoethyl)-2,3-dihydrobenzofuran (5-AEDB). The study was performed with urine-free spiked samples and authentic urine samples using eight different IAs for amphetamines and ecstasy. Results: All evaluated benzofurans showed cross-reactivity in some of the IAs tested, except for 5-AEDB. Urine samples of an intoxication case involving 5-MAPB, 5-APB and 5-EAPB were also positives in the IAs tested. Conclusion: There is an important variability in the cross-reactivity of the IAs for amphetamine and ecstasy caused by benzofurans depending on the immunoassay employed and the tested compounds.
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Therapeutic Drug Monitoring of Pentobarbital: Experience at an Academic Medical Center. Ther Drug Monit 2015; 37:783-91. [PMID: 26565790 DOI: 10.1097/ftd.0000000000000217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Pentobarbital is used for management of intractable seizures and for reducing elevated intracranial pressure. Dosing of pentobarbital can be aided by therapeutic drug monitoring (TDM). There is no commercially available automated assay for measurement of pentobarbital serum/plasma concentrations; consequently, chromatography-based assays are often used. METHODS Pentobarbital TDM was studied over a 14-year period at an academic medical center. 154 patients (94 adult, 60 pediatric) were identified who had pentobarbital levels ordered at least once during a hospital encounter. Chart review included patient diagnosis, indication for pentobarbital therapy, recent or concomitant medication with other barbiturates, patient disposition, organ donation, pentobarbital dosing changes, and neurosurgical procedures. Pentobarbital serum/plasma concentrations were determined on an automated clinical chemistry platform with a laboratory-developed test adapted from a urine barbiturates immunoassay. RESULTS Chart review showed therapeutic use of pentobarbital generally consistent with previously published literature. The most common errors observed involved confusion in barbiturate names (eg, mix-up of pentobarbital and phenobarbital in test ordering or in provider notes) that seemed to have minimal impact on TDM effectiveness, with pentobarbital serum/plasma concentrations generally within target ranges. The laboratory-developed pentobarbital immunoassay showed cross-reactivity with phenobarbital and butalbital that was eliminated by alkaline and heat pretreatment. The immunoassay was linear to 20 mcg/mL and correlated closely with gas chromatography-mass spectrometry measurements at a reference laboratory. CONCLUSIONS Pentobarbital TDM can be performed by immunoassay on an automated clinical chemistry platform, providing an alternative to chromatography-based methods. Confusion in barbiturate names is common, especially pentobarbital and phenobarbital.
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Quesada L, Gomila I, Fe A, Servera MA, Yates C, Morell-Garcia D, Castanyer B, Barceló B. Fenofibric Acid Can Cause False-Positive Urine Methylenedioxymethamphetamine Immunoassay Results. J Anal Toxicol 2015. [DOI: 10.1093/jat/bkv074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Cross-reactivity of steroid hormone immunoassays: clinical significance and two-dimensional molecular similarity prediction. BMC Clin Pathol 2014; 14:33. [PMID: 25071417 PMCID: PMC4112981 DOI: 10.1186/1472-6890-14-33] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 07/11/2014] [Indexed: 11/19/2022] Open
Abstract
Background Immunoassays are widely used in clinical laboratories for measurement of plasma/serum concentrations of steroid hormones such as cortisol and testosterone. Immunoassays can be performed on a variety of standard clinical chemistry analyzers, thus allowing even small clinical laboratories to do analysis on-site. One limitation of steroid hormone immunoassays is interference caused by compounds with structural similarity to the target steroid of the assay. Interfering molecules include structurally related endogenous compounds and their metabolites as well as drugs such as anabolic steroids and synthetic glucocorticoids. Methods Cross-reactivity of a structurally diverse set of compounds were determined for the Roche Diagnostics Elecsys assays for cortisol, dehydroepiandrosterone (DHEA) sulfate, estradiol, progesterone, and testosterone. These data were compared and contrasted to package insert data and published cross-reactivity studies for other marketed steroid hormone immunoassays. Cross-reactivity was computationally predicted using the technique of two-dimensional molecular similarity. Results The Roche Elecsys Cortisol and Testosterone II assays showed a wider range of cross-reactivity than the DHEA sulfate, Estradiol II, and Progesterone II assays. 6-Methylprednisolone and prednisolone showed high cross-reactivity for the cortisol assay, with high likelihood of clinically significant effect for patients administered these drugs. In addition, 21-deoxycortisol likely produces clinically relevant cross-reactivity for cortisol in patients with 21-hydroxylase deficiency, while 11-deoxycortisol may produce clinically relevant cross-reactivity in 11β-hydroxylase deficiency or following metyrapone challenge. Several anabolic steroids may produce clinically significant false positives on the testosterone assay, although interpretation is limited by sparse pharmacokinetic data for some of these drugs. Norethindrone therapy may impact immunoassay measurement of testosterone in women. Using two-dimensional similarity calculations, all compounds with high cross-reactivity also showed a high degree of similarity to the target molecule of the immunoassay. Conclusions Compounds producing cross-reactivity in steroid hormone immunoassays generally have a high degree of structural similarity to the target hormone. Clinically significant interactions can occur with structurally similar drugs (e.g., prednisolone and cortisol immunoassays; methyltestosterone and testosterone immunoassays) or with endogenous compounds such as 21-deoxycortisol that can accumulate to very high concentrations in certain disease conditions. Simple similarity calculations can help triage compounds for future testing of assay cross-reactivity.
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Krasowski MD, McMillin GA. Advances in anti-epileptic drug testing. Clin Chim Acta 2014; 436:224-36. [PMID: 24925169 DOI: 10.1016/j.cca.2014.06.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/29/2014] [Accepted: 06/03/2014] [Indexed: 12/12/2022]
Abstract
In the past twenty-one years, 17 new antiepileptic drugs have been approved for use in the United States and/or Europe. These drugs are clobazam, ezogabine (retigabine), eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, pregabalin, rufinamide, stiripentol, tiagabine, topiramate, vigabatrin and zonisamide. Therapeutic drug monitoring is often used in the clinical dosing of the newer anti-epileptic drugs. The drugs with the best justifications for drug monitoring are lamotrigine, levetiracetam, oxcarbazepine, stiripentol, and zonisamide. Perampanel, stiripentol and tiagabine are strongly bound to serum proteins and are candidates for monitoring of the free drug fractions. Alternative specimens for therapeutic drug monitoring are saliva and dried blood spots. Therapeutic drug monitoring of the new antiepileptic drugs is discussed here for managing patients with epilepsy.
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Affiliation(s)
- Matthew D Krasowski
- Department of Pathology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, United States.
| | - Gwendolyn A McMillin
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, United States; ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories Inc., Salt Lake City, UT, United States
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Krasowski MD, Ekins S. Using cheminformatics to predict cross reactivity of "designer drugs" to their currently available immunoassays. J Cheminform 2014; 6:22. [PMID: 24851137 PMCID: PMC4029917 DOI: 10.1186/1758-2946-6-22] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 05/07/2014] [Indexed: 12/03/2022] Open
Abstract
Background A challenge for drug of abuse testing is presented by ‘designer drugs’, compounds typically discovered by modifications of existing clinical drug classes such as amphetamines and cannabinoids. Drug of abuse screening immunoassays directed at amphetamine or methamphetamine only detect a small subset of designer amphetamine-like drugs, and those immunoassays designed for tetrahydrocannabinol metabolites generally do not cross-react with synthetic cannabinoids lacking the classic cannabinoid chemical backbone. This suggests complexity in understanding how to detect and identify whether a patient has taken a molecule of one class or another, impacting clinical care. Methods Cross-reactivity data from immunoassays specifically targeting designer amphetamine-like and synthetic cannabinoid drugs was collected from multiple published sources, and virtual chemical libraries for molecular similarity analysis were built. The virtual library for synthetic cannabinoid analysis contained a total of 169 structures, while the virtual library for amphetamine-type stimulants contained 288 compounds. Two-dimensional (2D) similarity for each test compound was compared to the target molecule of the immunoassay undergoing analysis. Results 2D similarity differentiated between cross-reactive and non-cross-reactive compounds for immunoassays targeting mephedrone/methcathinone, 3,4-methylenedioxypyrovalerone, benzylpiperazine, mephentermine, and synthetic cannabinoids. Conclusions In this study, we applied 2D molecular similarity analysis to the designer amphetamine-type stimulants and synthetic cannabinoids. Similarity calculations can be used to more efficiently decide which drugs and metabolites should be tested in cross-reactivity studies, as well as to design experiments and potentially predict antigens that would lead to immunoassays with cross reactivity for a broader array of designer drugs.
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Affiliation(s)
- Matthew D Krasowski
- Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242, USA
| | - Sean Ekins
- Collaborations in Chemistry, 5616 Hilltop Needmore Road, Fuquay-Varina, NC 27526, USA
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Petrie M, Lynch KL, Ekins S, Chang JS, Goetz RJ, Wu AHB, Krasowski MD. Cross-reactivity studies and predictive modeling of "Bath Salts" and other amphetamine-type stimulants with amphetamine screening immunoassays. Clin Toxicol (Phila) 2013; 51:83-91. [PMID: 23387345 DOI: 10.3109/15563650.2013.768344] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION The increasing abuse of amphetamine-like compounds presents a challenge for clinicians and clinical laboratories. Although these compounds may be identified by mass spectrometry-based assays, most clinical laboratories use amphetamine immunoassays that have unknown cross-reactivity with novel amphetamine-like drugs. To date, there has been a little systematic study of amphetamine immunoassay cross-reactivity with structurally diverse amphetamine-like drugs or of computational tools to predict cross-reactivity. METHODS Cross-reactivities of 42 amphetamines and amphetamine-like drugs with three amphetamines screening immunoassays (AxSYM(®) Amphetamine/Methamphetamine II, CEDIA(®) amphetamine/Ecstasy, and EMIT(®) II Plus Amphetamines) were determined. Two- and three-dimensional molecular similarity and modeling approaches were evaluated for the ability to predict cross-reactivity using receiver-operator characteristic curve analysis. RESULTS Overall, 34%-46% of the drugs tested positive on the immunoassay screens using a concentration of 20,000 ng/mL. The three immunoassays showed differential detection of the various classes of amphetamine-like drugs. Only the CEDIA assay detected piperazines well, while only the EMIT assay cross-reacted with the 2C class. All three immunoassays detected 4-substituted amphetamines. For the AxSYM and EMIT assays, two-dimensional molecular similarity methods that combined similarity to amphetamine/methamphetamine and 3,4-methylenedioxymethampetamine most accurately predicted cross-reactivity. For the CEDIA assay, three-dimensional pharmacophore methods performed best in predicting cross-reactivity. Using the best performing models, cross-reactivities of an additional 261 amphetamine-like compounds were predicted. CONCLUSIONS Existing amphetamines immunoassays unevenly detect amphetamine-like drugs, particularly in the 2C, piperazine, and β-keto classes. Computational similarity methods perform well in predicting cross-reactivity and can help prioritize testing of additional compounds in the future.
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Affiliation(s)
- M Petrie
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA
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King AM, Pugh JL, Menke NB, Krasowski MD, Lynch MJ, Pizon AF. Nonfatal tramadol overdose may cause false-positive phencyclidine on Emit-II assay. Am J Emerg Med 2013; 31:444.e5-9. [DOI: 10.1016/j.ajem.2012.05.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 05/25/2012] [Indexed: 10/27/2022] Open
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Wang Z, Zhang J, Zhang S, Shen J. Heterologous structure of coating antigen on sensitivity of ELISA for sulfamethazine: evidence from molecular similarity analysis. FOOD AGR IMMUNOL 2011. [DOI: 10.1080/09540105.2010.533752] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Ekins S, Williams AJ, Krasowski MD, Freundlich JS. In silico repositioning of approved drugs for rare and neglected diseases. Drug Discov Today 2011; 16:298-310. [PMID: 21376136 DOI: 10.1016/j.drudis.2011.02.016] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 02/09/2011] [Accepted: 02/22/2011] [Indexed: 02/08/2023]
Abstract
One approach to speed up drug discovery is to examine new uses for existing approved drugs, so-called 'drug repositioning' or 'drug repurposing', which has become increasingly popular in recent years. Analysis of the literature reveals many examples of US Food and Drug Administration-approved drugs that are active against multiple targets (also termed promiscuity) that can also be used to therapeutic advantage for repositioning for other neglected and rare diseases. Using proof-of-principle examples, we suggest here that with current in silico technologies and databases of the structures and biological activities of chemical compounds (drugs) and related data, as well as close integration with in vitro screening data, improved opportunities for drug repurposing will emerge for neglected or rare/orphan diseases.
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Affiliation(s)
- Sean Ekins
- Collaborations in Chemistry, 601 Runnymede Avenue, Jenkintown, PA 19046, USA.
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Cho W, Jung K, Regnier FE. Screening antibody and immunosorbent selectivity by two‐dimensional liquid chromatography‐MS/MS (2‐D LC‐MS/MS). J Sep Sci 2010; 33:1438-47. [PMID: 20405482 DOI: 10.1002/jssc.200900860] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Wonryeon Cho
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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Mueller R, Rodriguez AL, Dawson ES, Butkiewicz M, Nguyen TT, Oleszkiewicz S, Bleckmann A, Weaver CD, Lindsley CW, Conn PJ, Meiler J. Identification of Metabotropic Glutamate Receptor Subtype 5 Potentiators Using Virtual High-Throughput Screening. ACS Chem Neurosci 2010; 1:288-305. [PMID: 20414370 PMCID: PMC2857954 DOI: 10.1021/cn9000389] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 01/04/2010] [Indexed: 11/30/2022] Open
Abstract
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Selective potentiators of glutamate response at metabotropic glutamate receptor subtype 5 (mGluR5) have exciting potential for the development of novel treatment strategies for schizophrenia. A total of 1,382 compounds with positive allosteric modulation (PAM) of the mGluR5 glutamate response were identified through high-throughput screening (HTS) of a diverse library of 144,475 substances utilizing a functional assay measuring receptor-induced intracellular release of calcium. Primary hits were tested for concentration-dependent activity, and potency data (EC50 values) were used for training artificial neural network (ANN) quantitative structure−activity relationship (QSAR) models that predict biological potency from the chemical structure. While all models were trained to predict EC50, the quality of the models was assessed by using both continuous measures and binary classification. Numerical descriptors of chemical structure were used as input for the machine learning procedure and optimized in an iterative protocol. The ANN models achieved theoretical enrichment ratios of up to 38 for an independent data set not used in training the model. A database of ∼450,000 commercially available drug-like compounds was targeted in a virtual screen. A set of 824 compounds was obtained for testing based on the highest predicted potency values. Biological testing found 28.2% (232/824) of these compounds with various activities at mGluR5 including 177 pure potentiators and 55 partial agonists. These results represent an enrichment factor of 23 for pure potentiation of the mGluR5 glutamate response and 30 for overall mGluR5 modulation activity when compared with those of the original mGluR5 experimental screening data (0.94% hit rate). The active compounds identified contained 72% close derivatives of previously identified PAMs as well as 28% nontrivial derivatives of known active compounds.
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Affiliation(s)
| | | | - Eric S. Dawson
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232-6600
| | | | | | | | | | | | - Craig W. Lindsley
- Department of Chemistry
- Department of Pharmacology
- Institute for Chemical Biology
| | | | - Jens Meiler
- Department of Chemistry
- Department of Pharmacology
- Institute for Chemical Biology
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232-6600
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Krasowski MD, Pizon AF, Siam MG, Giannoutsos S, Iyer M, Ekins S. Using molecular similarity to highlight the challenges of routine immunoassay-based drug of abuse/toxicology screening in emergency medicine. BMC Emerg Med 2009; 9:5. [PMID: 19400959 PMCID: PMC2688477 DOI: 10.1186/1471-227x-9-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Accepted: 04/28/2009] [Indexed: 11/10/2022] Open
Abstract
Background Laboratory tests for routine drug of abuse and toxicology (DOA/Tox) screening, often used in emergency medicine, generally utilize antibody-based tests (immunoassays) to detect classes of drugs such as amphetamines, barbiturates, benzodiazepines, opiates, and tricyclic antidepressants, or individual drugs such as cocaine, methadone, and phencyclidine. A key factor in assay sensitivity and specificity is the drugs or drug metabolites that were used as antigenic targets to generate the assay antibodies. All DOA/Tox screening immunoassays can be limited by false positives caused by cross-reactivity from structurally related compounds. For immunoassays targeted at a particular class of drugs, there can also be false negatives if there is failure to detect some drugs or their metabolites within that class. Methods Molecular similarity analysis, a computational method commonly used in drug discovery, was used to calculate structural similarity of a wide range of clinically relevant compounds (prescription and over-the-counter medications, illicit drugs, and clinically significant metabolites) to the target ('antigenic') molecules of DOA/Tox screening tests. These results were compared with cross-reactivity data in the package inserts of immunoassays marketed for clinical testing. The causes for false positives for phencyclidine and tricyclic antidepressant screening immunoassays were investigated at the authors' medical center using gas chromatography/mass spectrometry as a confirmatory method. Results The results illustrate three major challenges for routine DOA/Tox screening immunoassays used in emergency medicine. First, for some classes of drugs, the structural diversity of common drugs within each class has been increasing, thereby making it difficult for a single assay to detect all compounds without compromising specificity. Second, for some screening assays, common 'out-of-class' drugs may be structurally similar to the target compound so that they account for a high frequency of false positives. Illustrating this point, at the authors' medical center, the majority of positive screening results for phencyclidine and tricyclic antidepressants assays were explained by out-of-class drugs. Third, different manufacturers have adopted varying approaches to marketed immunoassays, leading to substantial inter-assay variability. Conclusion The expanding structural diversity of drugs presents a difficult challenge for routine DOA/Tox screening that limit the clinical utility of these tests in the emergency medicine setting.
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