1
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Theodorsson E. Issues in assessing analytical performance specifications in healthcare systems assembling multiple laboratories and measuring systems. Clin Chem Lab Med 2024; 62:1520-1530. [PMID: 38329003 DOI: 10.1515/cclm-2023-1208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/30/2024] [Indexed: 02/09/2024]
Abstract
Analytical performance specifications (APS) are usually compared to the intermediate reproducibility uncertainty of measuring a particular measurand using a single in vitro diagnostic medical device (IVD MD). Healthcare systems assembling multiple laboratories that include several IVD MDs and cater to patients suffering from long-term disease conditions mean that samples from a patient are analyzed using a few IVD MDs, sometimes from different manufacturers, but rarely all IVD MDs in the healthcare system. The reproducibility uncertainty for results of a measurand measured within a healthcare system and the components of this measurement uncertainty is useful in strategies to minimize bias and overall measurement uncertainty within the healthcare system. The root mean squares deviation (RMSD) calculated as the sample standard deviation (SD) and relative SD includes both imprecision and bias and is appropriate for expressing such uncertainties. Results from commutable stabilized internal and external control samples, from measuring split natural patient samples or using big-data techniques, are essential in monitoring bias and measurement uncertainties in healthcare systems. Variance component analysis (VCA) can be employed to quantify the relative contributions of the most influential factors causing measurement uncertainty. Such results represent invaluable information for minimizing measurement uncertainty in the interest of the healthcare system's patients.
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Affiliation(s)
- Elvar Theodorsson
- Department of Biomedical and Clinical Sciences, Division of Clinical Chemistry and Pharmacology, Linkoping University, Linkoping, Sweden
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2
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Milinković N, Jovičić S. Measurement uncertainty. Adv Clin Chem 2023; 116:277-317. [PMID: 37852721 DOI: 10.1016/bs.acc.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Over time, the metrological concept of uncertainty in measurement has been very successfully integrated into laboratory sciences. For proper implementation, an understanding of specific metrology terminology and additional concepts such as metrology traceability and commutability is necessary. Although the original thinking about measurement uncertainty in laboratory medicine suggests the complexity of the concept, it basically refers to the result as the end product of the entire laboratory process. Although the data on measurement uncertainty can be expressed quantitatively, the basis of this concept is the continuous evaluation of all phases of the laboratory process. This means that laboratory experts should keep in mind that the extra-analytical phases (on which the uncertainty of the measurement results may depend the most) must be continuously monitored. The analytical phase can be "held in check" by established internal and external quality control processes. It is the internal/external quality control data that is used to calculate the numerical value of the measurement uncertainty of the measurement results. Although over time the awareness of laboratory experts regarding the concept of measurement uncertainty has increased, there are still many challenges that need to be followed, and the last one is how to achieve a balance between understanding, evaluation process and application of measurement uncertainty data of measurement results for complete and ultimate practical use.
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Affiliation(s)
- Neda Milinković
- University of Belgrade-Faculty of Pharmacy, Department of Medical Biochemistry, Belgrade, Serbia.
| | - Snežana Jovičić
- University of Belgrade-Faculty of Pharmacy, Department of Medical Biochemistry, Belgrade, Serbia
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3
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Wilkes EH. veRification: an R Shiny application for laboratory method verification and validation. Clin Chem Lab Med 2023; 61:1730-1739. [PMID: 37053372 DOI: 10.1515/cclm-2023-0158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/23/2023] [Indexed: 04/15/2023]
Abstract
OBJECTIVES According to international standards, clinical laboratories are required to verify the performance of assays prior to their implementation in routine practice. This typically involves the assessment of the assay's imprecision and trueness vs. appropriate targets. The analysis of these data is typically performed using frequentist statistical methods and often requires the use of closed source, proprietary software. The motivation for this paper was therefore to develop an open-source, freely available software capable of performing Bayesian analysis of verification data. METHODS The veRification application presented here was developed with the freely available R statistical computing environment, using the Shiny application framework. The codebase is fully open-source and is available as an R package on GitHub. RESULTS The developed application allows the user to analyze imprecision, trueness against external quality assurance, trueness against reference material, method comparison, and diagnostic performance data within a fully Bayesian framework (with frequentist methods also being available for some analyses). CONCLUSIONS Bayesian methods can have a steep learning curve and thus the work presented here aims to make Bayesian analyses of clinical laboratory data more accessible. Moreover, the development of the application and seeks to encourage the dissemination of open-source software within the community and provides a framework through which Shiny applications can be developed, shared, and iterated upon.
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Affiliation(s)
- Edmund H Wilkes
- Department of Clinical Biochemistry, North West London Pathology, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, UK
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4
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Sarmad S, Viant MR, Dunn WB, Goodacre R, Wilson ID, Chappell KE, Griffin JL, O'Donnell VB, Naicker B, Lewis MR, Suzuki T. A proposed framework to evaluate the quality and reliability of targeted metabolomics assays from the UK Consortium on Metabolic Phenotyping (MAP/UK). Nat Protoc 2023; 18:1017-1027. [PMID: 36828894 DOI: 10.1038/s41596-022-00801-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 11/24/2022] [Indexed: 02/26/2023]
Abstract
Targeted metabolite assays that measure tens or hundreds of pre-selected metabolites, typically using liquid chromatography-mass spectrometry, are increasingly being developed and applied to metabolic phenotyping studies. These are used both as standalone phenotyping methods and for the validation of putative metabolic biomarkers obtained from untargeted metabolomics studies. However, there are no widely accepted standards in the scientific community for ensuring reliability of the development and validation of targeted metabolite assays (referred to here as 'targeted metabolomics'). Most current practices attempt to adopt, with modifications, the strict guidance provided by drug regulatory authorities for analytical methods designed largely for measuring drugs and other xenobiotic analytes. Here, the regulatory guidance provided by the European Medicines Agency, US Food and Drug Administration and International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use are summarized. In this Perspective, we have adapted these guidelines and propose a less onerous 'tiered' approach to evaluate the reliability of a wide range of metabolomics analyses, addressing the need for community-accepted, harmonized guidelines for tiers other than full validation. This 'fit-for-purpose' tiered approach comprises four levels-discovery, screening, qualification and validation-and is discussed in the context of a range of targeted and untargeted metabolomics assays. Issues arising with targeted multiplexed metabolomics assays, and how these might be addressed, are considered. Furthermore, guidance is provided to assist the community with selecting the appropriate degree of reliability for a series of well-defined applications of metabolomics.
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Affiliation(s)
- Sarir Sarmad
- Department of Cardiovascular Sciences, University of Leicester and NIHR Leicester Biomedical Research Centre, Leicester, UK
| | - Mark R Viant
- Phenome Centre Birmingham, University of Birmingham, Birmingham, UK
| | - Warwick B Dunn
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular, and Integrative Biology, University of Liverpool, Liverpool, UK.,Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Royston Goodacre
- Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular, and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Ian D Wilson
- Division of Systems Medicine, Department of Metabolism, Digestion & Reproduction, Imperial College London, London, UK
| | - Katie E Chappell
- The National Phenome Centre, Department of Metabolism, Digestion & Reproduction, Imperial College London, London, UK
| | - Julian L Griffin
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, UK
| | - Valerie B O'Donnell
- Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | - Brendon Naicker
- Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | - Matthew R Lewis
- The National Phenome Centre, Department of Metabolism, Digestion & Reproduction, Imperial College London, London, UK
| | - Toru Suzuki
- Department of Cardiovascular Sciences, University of Leicester and NIHR Leicester Biomedical Research Centre, Leicester, UK. .,The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
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5
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Doleschall M, Darvasi O, Herold Z, Doleschall Z, Nyirő G, Somogyi A, Igaz P, Patócs A. Quantitative PCR from human genomic DNA: The determination of gene copy numbers for congenital adrenal hyperplasia and RCCX copy number variation. PLoS One 2022; 17:e0277299. [PMID: 36454796 PMCID: PMC9714944 DOI: 10.1371/journal.pone.0277299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 10/25/2022] [Indexed: 12/05/2022] Open
Abstract
Quantitative PCR (qPCR) is used for the determination of gene copy number (GCN). GCNs contribute to human disorders, and characterize copy number variation (CNV). The single laboratory method validations of duplex qPCR assays with hydrolysis probes on CYP21A1P and CYP21A2 genes, residing a CNV (RCCX CNV) and related to congenital adrenal hyperplasia, were performed using 46 human genomic DNA samples. We also performed the verifications on 5 qPCR assays for the genetic elements of RCCX CNV; C4A, C4B, CNV breakpoint, HERV-K(C4) CNV deletion and insertion alleles. Precision of each qPCR assay was under 1.01 CV%. Accuracy (relative error) ranged from 4.96±4.08% to 9.91±8.93%. Accuracy was not tightly linked to precision, but was significantly correlated with the efficiency of normalization using the RPPH1 internal reference gene (Spearman's ρ: 0.793-0.940, p>0.0001), ambiguity (ρ = 0.671, p = 0.029) and misclassification (ρ = 0.769, p = 0.009). A strong genomic matrix effect was observed, and target-singleplex (one target gene in one assay) qPCR was able to appropriately differentiate 2 GCN from 3 GCN at best. The analysis of all GCNs from the 7 qPCR assays using a multiplex approach increased the resolution of differentiation, and produced 98% of GCNs unambiguously, and all of which were in 100% concordance with GCNs measured by Southern blot, MLPA and aCGH. We conclude that the use of an internal (in one assay with the target gene) reference gene, the use of allele-specific primers or probes, and the multiplex approach (in one assay or different assays) are crucial for GCN determination using qPCR or other methods.
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Affiliation(s)
- Márton Doleschall
- Molecular Medicine Research Group, Eotvos Lorand Research Network and Semmelweis University, Budapest, Hungary
- * E-mail:
| | - Ottó Darvasi
- Hereditary Tumours Research Group, Eotvos Lorand Research Network and Semmelweis University, Budapest, Hungary
| | - Zoltán Herold
- Department of Internal Medicine and Oncology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Zoltán Doleschall
- Department of Pathogenetics, National Institute of Oncology, Budapest, Hungary
| | - Gábor Nyirő
- Molecular Medicine Research Group, Eotvos Lorand Research Network and Semmelweis University, Budapest, Hungary
- Department of Internal Medicine and Oncology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Anikó Somogyi
- Department of Internal Medicine and Hematology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Péter Igaz
- Molecular Medicine Research Group, Eotvos Lorand Research Network and Semmelweis University, Budapest, Hungary
- Department of Internal Medicine and Oncology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- Department of Endocrinology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Attila Patócs
- Hereditary Tumours Research Group, Eotvos Lorand Research Network and Semmelweis University, Budapest, Hungary
- Department of Internal Medicine and Hematology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary
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6
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Loh TP, Cooke BR, Markus C, Zakaria R, Tran MTC, Ho CS, Greaves RF. Method evaluation in the clinical laboratory. Clin Chem Lab Med 2022; 61:751-758. [PMID: 36327459 DOI: 10.1515/cclm-2022-0878] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 09/22/2022] [Indexed: 11/06/2022]
Abstract
Method evaluation is one of the critical components of the quality system that ensures the ongoing quality of a clinical laboratory. As part of implementing new methods or reviewing best practices, the peer-reviewed published literature is often searched for guidance. From the outset, Clinical Chemistry and Laboratory Medicine (CCLM) has a rich history of publishing methods relevant to clinical laboratory medicine. An insight into submissions, from editors' and reviewers' experiences, shows that authors still struggle with method evaluation, particularly the appropriate requirements for validation in clinical laboratory medicine. Here, we consider through a series of discussion points an overview of the status, challenges, and needs of method evaluation from the perspective of clinical laboratory medicine. We identify six key high-level aspects of clinical laboratory method evaluation that potentially lead to inconsistency. 1. Standardisation of terminology, 2. Selection of analytical performance specifications, 3. Experimental design of method evaluation, 4. Sample requirements of method evaluation, 5. Statistical assessment and interpretation of method evaluation data, and 6. Reporting of method evaluation data. Each of these areas requires considerable work to harmonise the practice of method evaluation in laboratory medicine, including more empirical studies to be incorporated into guidance documents that are relevant to clinical laboratories and are freely and widely available. To further close the loop, educational activities and fostering professional collaborations are essential to promote and improve the practice of method evaluation procedures.
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Affiliation(s)
- Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Brian R Cooke
- Department of Clinical Biochemistry, PathWest Laboratory Medicine, Fiona Stanley Hospital, Murdoch, WA, Australia
| | - Corey Markus
- Flinders University International Centre for Point-of-Care Testing, Flinders Health and Medical Research Institute, Adelaide, SA, Australia
| | - Rosita Zakaria
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia.,Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Mai Thi Chi Tran
- Faculty of Medical Technology, Hanoi Medical University, Hanoi, Vietnam.,Department of Clinical Biochemistry, National Children's Hospital, Hanoi, Vietnam
| | - Chung Shun Ho
- Biomedical Mass Spectrometry Unit, Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong
| | - Ronda F Greaves
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, VIC, Australia.,Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
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7
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Determination of n-3 index and arachidonic acid/eicosapentaenoic acid ratio in dried blood spot by gas chromatography. Biotechniques 2022; 73:25-33. [PMID: 35698842 DOI: 10.2144/btn-2021-0109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: Clinical and epidemiological studies suggest that analysis of the polyunsaturated fatty acids (PUFAs) is essential to evaluate nutritional requirements and disease risk. We describe a simple, sensitive and non-invasive method for estimating the n-3 index and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio in dried blood spots (DBSs). Experimental: After obtaining DBSs on a spot card, PUFAs were transesterified (direct, acidic transesterification) and subsequently extracted with n-hexane. Gas chromatography with flame ionization detection (GC-FID) was used to analyze the extracted PUFAs, and then n-3 index and AA/EPA ratio were calculated. Method validation showed satisfactory precision and linearity. Conclusion: This analysis is simple and reliable to estimate PUFA status, and it was successfully applied to samples from 20 subjects, demonstrating its applicability.
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8
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Coskun A, Theodorsson E, Oosterhuis WP, Sandberg S. Measurement uncertainty for practical use. Clin Chim Acta 2022; 531:352-360. [PMID: 35513038 DOI: 10.1016/j.cca.2022.04.1003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 11/03/2022]
Abstract
Uncertainty is an inseparable part of all kinds of measurements performed in clinical laboratories. Accreditation standards including the ISO/IEC 17025:2017 and ISO 15189:2012 require that laboratories have routines for calculating the measurement uncertainty of reported results. Various guidelines such as CLSI EP29, Nordest 537, and ISO 20914:2019 have proposed methods for this purpose. However, due to the conceived complexity of the proposed calculation methods, these guidelines have not been generally and effectively applied in clinical laboratories. High workload and measurand heterogeneity favor a pragmatic utilitarian approach. The purpose of this paper is to describe such an approach, including its advantages and disadvantages. Measurement uncertainty should include the most influential factors affecting patients' test results. Since patients' samples for the same measurand can be analyzed in one laboratory or several laboratories using different measuring systems, the measurement uncertainty should be calculated using results obtained from analyzing the same internal quality control material if commutable or patients pooled/split samples.
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Affiliation(s)
- Abdurrahman Coskun
- EFLM Task and Finish Group on Practical Approach to Measurement Uncertainty, Milan, Italy; School of Medicine, Department of Medical Biochemistry, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey.
| | - Elvar Theodorsson
- EFLM Task and Finish Group on Practical Approach to Measurement Uncertainty, Milan, Italy; Division of Clinical Chemistry, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Wytze P Oosterhuis
- EFLM Task and Finish Group on Practical Approach to Measurement Uncertainty, Milan, Italy; Reinier Haga Medisch Diagnostisch Centrum, Delft, The Netherlands
| | - Sverre Sandberg
- EFLM Task and Finish Group on Practical Approach to Measurement Uncertainty, Milan, Italy; The Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Diaconess Hospital; Department of Global Health and Primary Health Care, University of Bergen
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9
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Milevoj Kopčinović L, Juričić G, Bokulić A, Vukasović I, Ćelap I, Čičak H, Kocijančić M, Miloš M, Lovrić M, Siter Kuprešanin M, Hrabrić Vlah S, Miletić M. Verification policies in Croatian medical biochemistry laboratories: a survey of the practice. Biochem Med (Zagreb) 2022; 32:020703. [PMID: 35464743 PMCID: PMC8996323 DOI: 10.11613/bm.2022.020703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 01/24/2022] [Indexed: 11/03/2022] Open
Abstract
Introduction Materials and methods Results Conclusions
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Affiliation(s)
- Lara Milevoj Kopčinović
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Clinical Chemistry, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
- Corresponding author:
| | - Gordana Juričić
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Laboratory Diagnostics, General hospital Pula, Pula, Croatia
| | - Adriana Bokulić
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Laboratory of Endocrinology, Department of Oncology and Nuclear Medicine, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Ines Vukasović
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Clinical Chemistry, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
- School of Medicine, Catholic University of Croatia, Zagreb, Croatia
| | - Ivana Ćelap
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Clinical Chemistry, Sestre milosrdnice University Hospital Center, Zagreb, Croatia
| | - Helena Čičak
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Medical Laboratory Diagnostics, University Hospital “Sveti Duh”, Zagreb, Croatia
| | - Marija Kocijančić
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Laboratory Medicine, Central Laboratory, University Clinic Halle, Halle (Saale), Germany
| | - Marija Miloš
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
- Faculty of Pharmacy, University of Mostar, Mostar, Bosnia and Herzegovina
| | - Mila Lovrić
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Zagreb, Croatia
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
- School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Marija Siter Kuprešanin
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Department of Medical Laboratory Diagnostics, University Hospital “Sveti Duh”, Zagreb, Croatia
| | - Snježana Hrabrić Vlah
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Clinical Department of Laboratory Diagnostics, Clinical Hospital Center Rijeka, Rijeka, Croatia
| | - Manuela Miletić
- Working group for method verification and validation of the Croatian Society of Medical Biochemistry and Laboratory Medicine and Croatian Chamber of Medical Biochemists, Zagreb, Croatia
- Laboratory of Medical Biochemistry, Zagreb County Health Center, Velika Gorica, Croatia
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10
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Lapić I, Šegulja D, Dukić K, Bogić A, Lončar Vrančić A, Komljenović S, Šparakl T, Grdiša Teodorović K, Cigula Kurajica V, Baršić Lapić I, Kralik Oguić S, Kozmar A, Vogrinc Ž, Rogić D. Analytical validation of 39 clinical chemistry tests and 17 immunoassays on the Alinity analytical system. Scandinavian Journal of Clinical and Laboratory Investigation 2022; 82:199-209. [DOI: 10.1080/00365513.2022.2056856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Ivana Lapić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Dragana Šegulja
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Kristina Dukić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Anamarija Bogić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Ana Lončar Vrančić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Sven Komljenović
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Tajana Šparakl
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | | | - Vlasta Cigula Kurajica
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Ivana Baršić Lapić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Saša Kralik Oguić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Ana Kozmar
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Željka Vogrinc
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
| | - Dunja Rogić
- Department of Laboratory Diagnostics, University Hospital Center Zagreb, Zagreb, Croatia
- Faculty of Pharmacy and Biochemistry, University of Zagreb, Zagreb, Croatia
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11
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Serdar CC, Cihan M, Yücel D, Serdar MA. Sample size, power and effect size revisited: simplified and practical approaches in pre-clinical, clinical and laboratory studies. Biochem Med (Zagreb) 2021; 31:010502. [PMID: 33380887 PMCID: PMC7745163 DOI: 10.11613/bm.2021.010502] [Citation(s) in RCA: 365] [Impact Index Per Article: 121.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/12/2020] [Indexed: 12/14/2022] Open
Abstract
Calculating the sample size in scientific studies is one of the critical issues as regards the scientific contribution of the study. The sample size critically affects the hypothesis and the study design, and there is no straightforward way of calculating the effective sample size for reaching an accurate conclusion. Use of a statistically incorrect sample size may lead to inadequate results in both clinical and laboratory studies as well as resulting in time loss, cost, and ethical problems. This review holds two main aims. The first aim is to explain the importance of sample size and its relationship to effect size (ES) and statistical significance. The second aim is to assist researchers planning to perform sample size estimations by suggesting and elucidating available alternative software, guidelines and references that will serve different scientific purposes.
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Affiliation(s)
- Ceyhan Ceran Serdar
- Medical Biology and Genetics, Faculty of Medicine, Ankara Medipol University, Ankara, Turkey
| | - Murat Cihan
- Ordu University Training and Research Hospital, Ordu, Turkey
| | - Doğan Yücel
- Department of Medical Biochemistry, Lokman Hekim University School of Medicine, Ankara, Turkey
| | - Muhittin A Serdar
- Department of Medical Biochemistry, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey
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12
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Abdel GMT, El-Masry MI. Verification of quantitative analytical methods in medical laboratories. J Med Biochem 2021; 40:225-236. [PMID: 34177366 PMCID: PMC8199534 DOI: 10.5937/jomb0-24764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 01/03/2020] [Indexed: 11/06/2022] Open
Abstract
Background Globally, all medical laboratories seeking accreditation should meet international quality standards to perform certain specific tests. Quality management program provides disciplines targeted to ensure that quality standards have been implemented by a laboratory in order to generate correct results. The hallmark of the accreditation process is method verification and quality assurance. Before introducing a new method in your laboratory, it is important to assess certain performance characteristics that reflect the concept of method verification. Methods In this review, we illustrated how to verify the performance characteristics of a new method according to the recent guidelines. It includes an assessment of precision, trueness, analytical sensitivity, detection limits, analytical specificity, interference, measuring range, linearity, and measurement uncertainty. Conclusions Although the presence of several updated guidelines used to determine the performance characteristics of new methods in clinical chemistry laboratories, the real practice raised several concerns with the application of these guidelines which in need for further consideration in the upcoming updates of these guidelines.
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Affiliation(s)
| | - Muhammad I El-Masry
- Kafr El-sheikh University, Faculty of Medicine, Departments of Clinical Pathology, Egypt
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13
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Park M, Kim MS, Yoo J, Jo MS. Validation of the whole-body counting measurement in a radiation emergency. Appl Radiat Isot 2020; 168:109476. [PMID: 33097379 DOI: 10.1016/j.apradiso.2020.109476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/13/2020] [Indexed: 11/16/2022]
Abstract
Whole-body measurement can provide fast and accurate results in radiation emergencies. The whole-body counting method needs to be validated to guarantee the reliability and accuracy of the measurement. This study provides data related to the validation of the whole-body measurement using the stand-up type whole-body counter. Several parameters, including the sensitivity, accuracy, uncertainty, were considered for validation. The results indicate that the method of whole-body measurement is reliable for assessment of internal contamination.
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Affiliation(s)
- MinSeok Park
- National Radiation Emergency Center, Korea Institute of Radiological and Medical Sciences, 01812, Seoul, Republic of Korea
| | - Min-Sub Kim
- National Radiation Emergency Center, Korea Institute of Radiological and Medical Sciences, 01812, Seoul, Republic of Korea
| | - Jaeryong Yoo
- National Radiation Emergency Center, Korea Institute of Radiological and Medical Sciences, 01812, Seoul, Republic of Korea.
| | - Min-Su Jo
- National Radiation Emergency Center, Korea Institute of Radiological and Medical Sciences, 01812, Seoul, Republic of Korea
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Becker MG, Liang D, Cooper B, Le Y, Taylor T, Lee ER, Wu S, Sandstrom P, Ji H. Development and Application of Performance Assessment Criteria for Next-Generation Sequencing-Based HIV Drug Resistance Assays. Viruses 2020; 12:E627. [PMID: 32532083 PMCID: PMC7354553 DOI: 10.3390/v12060627] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/29/2020] [Accepted: 06/07/2020] [Indexed: 12/19/2022] Open
Abstract
Next-generation sequencing (NGS)-based HIV drug resistance (HIVDR) assays outperform conventional Sanger sequencing in scalability, sensitivity, and quantitative detection of minority resistance variants. Thus far, HIVDR assays have been applied primarily in research but rarely in clinical settings. One main obstacle is the lack of standardized validation and performance evaluation systems that allow regulatory agencies to benchmark and accredit new assays for clinical use. By revisiting the existing principles for molecular assay validation, here we propose a new validation and performance evaluation system that helps to both qualitatively and quantitatively assess the performance of an NGS-based HIVDR assay. To accomplish this, we constructed a 70-specimen proficiency test panel that includes plasmid mixtures at known ratios, viral RNA from infectious clones, and anonymized clinical specimens. We developed assessment criteria and benchmarks for NGS-based HIVDR assays and used these to assess data from five separate MiSeq runs performed in two experienced HIVDR laboratories. This proposed platform may help to pave the way for the standardization of NGS HIVDR assay validation and performance evaluation strategies for accreditation and quality assurance purposes in both research and clinical settings.
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Affiliation(s)
- Michael G. Becker
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
| | - Dun Liang
- ViroDx Clinical Diagnostics Laboratory, St. Louis, MO 63017, USA; (D.L.); (B.C.); (Y.L.)
| | - Breanna Cooper
- ViroDx Clinical Diagnostics Laboratory, St. Louis, MO 63017, USA; (D.L.); (B.C.); (Y.L.)
| | - Yan Le
- ViroDx Clinical Diagnostics Laboratory, St. Louis, MO 63017, USA; (D.L.); (B.C.); (Y.L.)
| | - Tracy Taylor
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
| | - Emma R. Lee
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
| | - Sutan Wu
- SutanStats, St. Louis, MO 63017, USA;
| | - Paul Sandstrom
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Hezhao Ji
- National HIV and Retrovirology Laboratories, National Microbiology Laboratory at JC Wilt Infectious Diseases Research Center, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada; (M.G.B.); (T.T.); (E.R.L.); (P.S.)
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
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Berthias F, Wang Y, Alhajji E, Rieul B, Moussa F, Benoist JF, Maître P. Identification and quantification of amino acids and related compounds based on Differential Mobility Spectrometry. Analyst 2020; 145:4889-4900. [DOI: 10.1039/d0an00377h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A new metabolite descriptor allowing fast quantification for the diagnosis of metabolic diseases.
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Affiliation(s)
- Francis Berthias
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- Orsay
- France
| | - Yali Wang
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- Orsay
- France
| | - Eskander Alhajji
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- Orsay
- France
| | - Bernard Rieul
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- Orsay
- France
| | - Fathi Moussa
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- Orsay
- France
| | - Jean-François Benoist
- Université Paris-Saclay
- Lipides
- Systèmes Analytiques et Biologiques
- Châtenay-Malabry
- France
| | - Philippe Maître
- Université Paris-Saclay
- CNRS
- Institut de Chimie Physique
- Orsay
- France
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Lukić V, Ignjatović S. Optimizing moving average control procedures for small-volume laboratories: can it be done? Biochem Med (Zagreb) 2019; 29:030710. [PMID: 31624463 PMCID: PMC6784424 DOI: 10.11613/bm.2019.030710] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/17/2019] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Moving average (MA) means calculating the average value from a set of patient results and further using that value for analytical quality control purposes. The aim of this study was to examine whether the selection, optimization and validation of MA procedures can be performed using the already described bias detection simulation method and whether it is possible to select appropriate MA procedures for a laboratory with a small daily testing volume. MATERIALS AND METHODS The study was done on four analytes: creatinine, potassium, sodium and albumin. All patient results of these tests processed during six months were taken from the laboratory information system. Using the MA Generator software, different MA procedures were analysed. Different inclusion criteria, calculation formulas, batch sizes and weighting factors were tested. Selection of optimal MA procedures was based on their ability to detect simulated biases of different sizes. After optimization, the validation of MA procedures was done. The results were presented by bias detection curves and MA validation charts. RESULTS Simple MA procedures for albumin and sodium without truncation limits were selected as optimal. Exponentially weighted MA procedures were found optimal for creatinine and potassium, with the upper truncation limits of 150 μmol/L and 6 mmol/L, respectively. CONCLUSIONS It has been experimentally confirmed that it is possible to perform the selection, optimization and validation of MA procedures using the bias detection simulation method. Also, it is possible to define MA procedures optimal for a laboratory with a small daily testing volume.
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Affiliation(s)
- Vera Lukić
- Department of laboratory diagnostics, Railway Healthcare Institute, Belgrade, Serbia
| | - Svetlana Ignjatović
- Department of Medical Biochemistry, University of Belgrade, Faculty of Pharmacy, Belgrade, Serbia
- Center for Medical Biochemistry, Clinical Center of Serbia, Belgrade, Serbia
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17
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18
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Hand M, Crampton A, Thomas A, Kilpatrick ES. A survey of clinical laboratory instrument verification in the UK and New Zealand. Ann Clin Biochem 2019; 56:275-282. [DOI: 10.1177/0004563218823804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background Clinical laboratory instrument verification testing is often an accreditation requirement. However, it is not known what verification procedures are in routine use or how often the process identifies problems which need addressing prior to testing clinical samples. Objective To investigate which standards are currently being used for laboratory verification in UK and New Zealand (NZ) clinical laboratories and to help establish if the activity justifies the effort required. Methods A survey of verification of clinical laboratory instrumentation was distributed to members of the Association for Clinical Biochemistry and Laboratory Medicine and New Zealand Institute of Medical Laboratory Scientists. The survey consisted of questions on the verification elements used and whether acceptance criteria were met. Results Nineteen of 72 (26%) of responders only used organization-developed protocols for verification, 20/72 (28%) solely used national/international guidelines, while 16/72 (22%) used a combination. Manufacturers’ claims were partly or entirely used as acceptance criteria for imprecision (89%), accuracy (64%) and analytical measuring range (94%), with these being met on 61%, 67% and 93% of occasions, respectively. For patient comparison and linearity, acceptance criteria were met by 71% and 91%. Only 27–36% undertook any troubleshooting before accepting a failed component of verification. Conclusions Laboratories in the UK and NZ are currently using a variety of verification standards and acceptance criteria for instrument verification. It is common for instruments to fail, especially following the assessment of imprecision and accuracy. While this suggests the process is warranted, only a minority address failed elements before accepting verification.
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Affiliation(s)
| | | | - Annette Thomas
- Weqas, Cardiff and Vale University Health Board, Cardiff, Wales, UK
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Oosterhuis WP, Bayat H, Armbruster D, Coskun A, Freeman KP, Kallner A, Koch D, Mackenzie F, Migliarino G, Orth M, Sandberg S, Sylte MS, Westgard S, Theodorsson E. The use of error and uncertainty methods in the medical laboratory. Clin Chem Lab Med 2019; 56:209-219. [PMID: 28796637 DOI: 10.1515/cclm-2017-0341] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/04/2017] [Indexed: 11/15/2022]
Abstract
Error methods - compared with uncertainty methods - offer simpler, more intuitive and practical procedures for calculating measurement uncertainty and conducting quality assurance in laboratory medicine. However, uncertainty methods are preferred in other fields of science as reflected by the guide to the expression of uncertainty in measurement. When laboratory results are used for supporting medical diagnoses, the total uncertainty consists only partially of analytical variation. Biological variation, pre- and postanalytical variation all need to be included. Furthermore, all components of the measuring procedure need to be taken into account. Performance specifications for diagnostic tests should include the diagnostic uncertainty of the entire testing process. Uncertainty methods may be particularly useful for this purpose but have yet to show their strength in laboratory medicine. The purpose of this paper is to elucidate the pros and cons of error and uncertainty methods as groundwork for future consensus on their use in practical performance specifications. Error and uncertainty methods are complementary when evaluating measurement data.
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Affiliation(s)
- Wytze P Oosterhuis
- Department of Clinical Chemistry and Haematology, Zuyderland Medical Center, Henri Dunantstraat 5, 6419 PC Heerlen, The Netherlands, Phone: +31 45 5766341
| | | | | | - Abdurrahman Coskun
- Acibadem University, School of Medicine, Department of Medical Biochemistry, Istanbul, Turkey
| | - Kathleen P Freeman
- IDEXX Laboratories, Ltd, Grange House, Sandbeck Industrial Estate, Wetherby, West Yorkshire, UK
| | - Anders Kallner
- Department of Clinical Chemistry, Karolinska University Hospital Stockholm, Stockholm, Sweden
| | - David Koch
- Emory University School of Medicine, Grady Memorial Hospital in Atlanta, GA, USA
| | - Finlay Mackenzie
- University Hospitals Birmingham NHS Foundation Trust, Institute of Research and Development, Birmingham, UK
| | | | - Matthias Orth
- Vinzenz von Paul Kliniken gGmbH, Institut für Laboratoriumsmedizin, Stuttgart, Baden-Wurttemberg, Germany
| | - Sverre Sandberg
- Norwegian Quality Improvement of Primary Care Laboratories (Noklus), Institute of Global Health and Primary Health Care, University of Bergen and Laboratory of Clinical Biochemistry Haukeland University Hospital, Bergen, Norway
| | - Marit S Sylte
- University of Bergen and Laboratory of Clinical Biochemistry Haukeland University Hospital, Bergen, Norway
| | | | - Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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Silva Dalsasso Joaquim L, Granzotto N, Dos Santos LF, Fontana Roman C, Martinello F. Analytical validation of an in-house method for adenosine deaminase determination. J Clin Lab Anal 2018; 33:e22823. [PMID: 30489653 DOI: 10.1002/jcla.22823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 11/02/2018] [Accepted: 11/04/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The adenosine deaminase (ADA) enzyme is a marker of inflammatory processes whose activity can be measured through a colorimetric method developed as an in-house assay. This validation can reduce costs and expand the alternatives for laboratory diagnosis. METHODS The ADA analysis was achieved through a modified form of Giusti and Galanti's (1984) method. The following parameters were characterized: calibration curve, linearity, analytical sensitivity, limit of detection, limit of quantification, method working range, precision (within-assay and between-assay), bias, total analytical error, and sample stability. The results were statistically evaluated and compared with quality specifications based on biological variations and the performance of commercial tests. RESULTS The analytical sensitivity and limit of detection (0.013 and 3.0 U/L, respectively) were lower than those of commercial tests. The method's working range was 3.2-100.0 U/L. According to the quality specification, the method showed optimum performance with a bias <3.5%. However, repeatability (2.2% and 1.7% for normal- and high-activity samples, respectively) and reproducibility achieved worse results when compared to commercial tests. The method demonstrated an inappropriate between-assay precision for low enzymatic activity (10.4%) and the minimum and desirable performance for medium (8.8%) and high (5.0%) activities, respectively. It also presented at least a minimum performance (<25%) for the total analytical error of the three analyzed samples. The pleural fluid samples were found to be stable at -20°C for six days. CONCLUSION The findings show that the in-house method displays an acceptable performance and is capable of generating results comparable to existing commercial tests.
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Affiliation(s)
| | - Natalli Granzotto
- Department of Clinical Analysis, Federal University of Santa Catarina, Florianópolis, Brazil
| | | | - Camila Fontana Roman
- Department of Clinical Analysis, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Flávia Martinello
- Department of Clinical Analysis, Federal University of Santa Catarina, Florianópolis, Brazil
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Diaz de Pool JDN, Van Den Berg SAA, Pilgram GSK, Ballieux BEPB, Van Der Westerlaken LAJ. Validation of the blood gas analyzer for pH measurements in IVF culture medium: Prevent suboptimal culture conditions. PLoS One 2018; 13:e0206707. [PMID: 30418977 PMCID: PMC6231605 DOI: 10.1371/journal.pone.0206707] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 10/17/2018] [Indexed: 12/04/2022] Open
Abstract
Measurement of pH in IVF-media using the blood gas analyzer (BGA) requires validation, because IVF-media is outside the intended scope of the BGA. To determine whether the Siemens Rapidpoint 500 BGA is suitable for pH measurements in IVF-media this study will validate the BGA and assess its accuracy. In this method comparison study, the pH of over three hundred IVF-media samples was measured with the BGA and a pH electrode (Hanna pH checker). The precision of both the BGA and the pH electrode were excellent (coefficient variation <1.4%). However, the closeness of agreement between measured values of both devices were not equivalent to each other in the tested IVF-media, showing 15% to 85% accordance between devices. The pH measured with the blood gas analyzer was also significantly higher in the tested media, compared to that measured by the pH electrode. One of the tested media did not reach its target pH when it was measured with the BGA, even at 9% CO2. The results show that the validated blood gas analyzer produces excellent results in terms of precision but not in terms of accuracy. Inaccurate measurement may lead to misinterpretation of results and consequently to suboptimal culture conditions. Therefore, each laboratory is encouraged to perform a validation of their BGA.
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Affiliation(s)
- Juan D. N. Diaz de Pool
- Department of Gynecology, Leiden University Medical Center, Leiden, The Netherlands
- * E-mail:
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22
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Berg T, Eliassen E, Jørgenrud B, Kabashi S, Petukhov A, Bogstrand ST. Determination of phosphatidylethanol 16:0/18:1 in whole blood by 96-well supported liquid extraction and UHPLC-MS/MS. J Clin Lab Anal 2018; 33:e22631. [PMID: 30047172 DOI: 10.1002/jcla.22631] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/20/2018] [Accepted: 07/05/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Phosphatidylethanols (PEths) are specific, direct alcohol biomarkers that can be determined in human blood to distinguish between heavy and social drinking. PEth 16:0/18:1 is among the most predominant PEth homologues in human blood. The aim of the study was to develop a high throughput and sensitive UHPLC-MS/MS method for the determination of PEth 16:0/18:1 in whole blood. METHODS Whole blood samples were prepared by 96-well supported liquid extraction (SLE). Extracted samples were analyzed for PEth 16:0/18:1 by reversed phase UHPLC-MS/MS. RESULTS The developed UHPLC-MS/MS method was fully validated in whole blood with PEth 16:0/18:1-D5 as internal standard. Intermediate precision and intermediate accuracy were within ≤± 12% and ≤± 17%, respectively, at PEth 16:0/18:1 concentrations of 1.4-2112 ng/mL (2.0-3004 nmol/L). Limit of quantification (LOQ) was 1.7 ng/mL (2.4 nmol/L). CONCLUSION For the first time, 96-well SLE was used for preparation of a PEth homologue in biological samples. A mixture of tert-butyl methyl ether and 2-propanol (5:1, v:v) was chosen as organic eluent based on an evaluation of extraction recovery, purity of extracts, and evaporation time. The developed UHPLC-MS/MS method can be used for high throughput analyses and sensitive determinations of PEth 16:0/18:1 in whole blood.
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Affiliation(s)
- Thomas Berg
- Section of Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
| | - Elin Eliassen
- Section of Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
| | - Benedicte Jørgenrud
- Section of Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
| | - Saranda Kabashi
- Section of Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
| | - Alexey Petukhov
- Moscow Scientific Practical Center of Drug Addiction, Moscow Municipal Department of Healthcare, Moscow, Russia.,I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Stig Tore Bogstrand
- Section of Drug Abuse Research, Department of Forensic Sciences, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Lovisenberg Diaconal University College, Oslo, Norway
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Ubillos I, Campo JJ, Jiménez A, Dobaño C. Development of a high-throughput flexible quantitative suspension array assay for IgG against multiple Plasmodium falciparum antigens. Malar J 2018; 17:216. [PMID: 29843713 PMCID: PMC5975539 DOI: 10.1186/s12936-018-2365-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/22/2018] [Indexed: 11/28/2022] Open
Abstract
Background Antibody responses to Plasmodium falciparum play a critical role in disease control. Finding reliable IgG biomarkers of protection is complicated by a parasite proteome of over 5000 proteins, some with polymorphisms. Studies of anti-malarial naturally acquired and vaccine immunity would benefit from a standard high-throughput immunoassay to measure multiple antibodies. A multiplex quantitative suspension assay to measure antigen-specific IgGs was developed and its precision (reproducibility and repeatability), dynamic range, limits of detection and quantification, and non-specific binding to different P. falciparum proteins tested. A set of 288 human plasma samples from a malaria-endemic region were analysed twice by two different operators. Another set of samples from 9 malaria-naïve and 10 malaria-exposed individuals were repetitively assayed during 22 consecutive days. Positive controls, negative controls, blanks and microspheres coated with bovine serum albumin were included in all assays. Results The multiplex quantitative suspension assay demonstrated low non-specific signal and good estimates of precision and reproducibility between operators. The overall mean of non-specific binding measured in 288 plasma samples was 32.83 to ± 44.81 median fluorescence intensity (MFI). Repeatability was 7.66% ± 15.89 between triplicates for all antigens and samples, being lower in samples from malaria-exposed than malaria-naïve individuals. No evidence of significantly different variance across days in MFI or arbitrary units (AU)/mL was found, assuming homogeneity of variance between days of analysis. Intra-class correlation coefficient between 22 days of analysis was 0.98 (0.97–0.98) for MFI units and 0.9 (0.87–0.93) for AU/mL. Reproducibility between operators for all samples and antigens had an overall adjusted correlation of 0.929 for MFI and 0.836 for AU/mL. Conclusions This high-throughput multiplex immunoassay is simple and highly reproducible. This represents an asset for malaria vaccine studies involving CSP-specific antibodies and selected antigens for sero-epidemiological purposes. Measuring a multiplex antigen panel in a single reaction will help to assess not only vaccine immunogenicity but also potential malaria vaccine effects on naturally acquired immune responses. This will accelerate the identification of immune correlates of protection, down-selection of vaccine formulations, antigen discovery and guide second-generation vaccine design. Electronic supplementary material The online version of this article (10.1186/s12936-018-2365-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Itziar Ubillos
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Joseph J Campo
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.,Antigen Discovery, Inc, Irvine, CA, USA
| | - Alfons Jiménez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Catalonia, Spain.
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Antonelli G, Padoan A, Aita A, Sciacovelli L, Plebani M. Verification of examination procedures in clinical laboratory for imprecision, trueness and diagnostic accuracy according to ISO 15189:2012: a pragmatic approach. Clin Chem Lab Med 2017; 55:1501-1508. [PMID: 28222014 DOI: 10.1515/cclm-2016-0894] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 01/04/2017] [Indexed: 11/15/2022]
Abstract
Background The International Standard ISO 15189 is recognized as a valuable guide in ensuring high quality clinical laboratory services and promoting the harmonization of accreditation programmes in laboratory medicine. Examination procedures must be verified in order to guarantee that their performance characteristics are congruent with the intended scope of the test. The aim of the present study was to propose a practice model for implementing procedures employed for the verification of validated examination procedures already used for at least 2 years in our laboratory, in agreement with the ISO 15189 requirement at the Section 5.5.1.2. Methods In order to identify the operative procedure to be used, approved documents were identified, together with the definition of performance characteristics to be evaluated for the different methods; the examination procedures used in laboratory were analyzed and checked for performance specifications reported by manufacturers. Then, operative flow charts were identified to compare the laboratory performance characteristics with those declared by manufacturers. Results The choice of performance characteristics for verification was based on approved documents used as guidance, and the specific purpose tests undertaken, a consideration being made of: imprecision and trueness for quantitative methods; diagnostic accuracy for qualitative methods; imprecision together with diagnostic accuracy for semi-quantitative methods. Conclusions The described approach, balancing technological possibilities, risks and costs and assuring the compliance of the fundamental component of result accuracy, appears promising as an easily applicable and flexible procedure helping laboratories to comply with the ISO 15189 requirements.
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Fachi MM, Leonart LP, Cerqueira LB, Pontes FLD, de Campos ML, Pontarolo R. A systematic and critical review on bioanalytical method validation using the example of simultaneous quantitation of antidiabetic agents in blood. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1055-1056:61-71. [DOI: 10.1016/j.jchromb.2017.04.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 02/13/2017] [Accepted: 04/12/2017] [Indexed: 12/18/2022]
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Bowen RAR, Adcock DM. Blood collection tubes as medical devices: The potential to affect assays and proposed verification and validation processes for the clinical laboratory. Clin Biochem 2016; 49:1321-1330. [PMID: 27765677 DOI: 10.1016/j.clinbiochem.2016.10.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/11/2016] [Accepted: 10/12/2016] [Indexed: 01/28/2023]
Abstract
Blood collection tubes (BCTs) are an often under-recognized variable in the preanalytical phase of clinical laboratory testing. Unfortunately, even the best-designed and manufactured BCTs may not work well in all clinical settings. Clinical laboratories, in collaboration with healthcare providers, should carefully evaluate BCTs prior to putting them into clinical use to determine their limitations and ensure that patients are not placed at risk because of inaccuracies due to poor tube performance. Selection of the best BCTs can be achieved through comparing advertising materials, reviewing the literature, observing the device at a scientific meeting, receiving a demonstration, evaluating the device under simulated conditions, or testing the device with patient samples. Although many publications have discussed method validations, few detail how to perform experiments for tube verification and validation. This article highlights the most common and impactful variables related to BCTs and discusses the validation studies that a typical clinical laboratory should perform when selecting BCTs. We also present a brief review of how in vitro diagnostic devices, particularly BCTs, are regulated in the United States, the European Union, and Canada. The verification and validation of BCTs will help to avoid the economic and human costs associated with incorrect test results, including poor patient care, unnecessary testing, and delays in test results. We urge laboratorians, tube manufacturers, diagnostic companies, and other researchers to take all the necessary steps to protect against the adverse effects of BCT components and their additives on clinical assays.
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Affiliation(s)
- Raffick A R Bowen
- Department of Pathology, Rm H1401J, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA 94305-5627, United States.
| | - Dorothy M Adcock
- Colorado Coagulation, Laboratory Corporation of America® Holdings, Englewood, CO, United States
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Fermier B, Blasco H, Godat E, Bocca C, Moënne-Loccoz J, Emond P, Andres CR, Laffon M, Ferrandière M. Specific Metabolome Profile of Exhaled Breath Condensate in Patients with Shock and Respiratory Failure: A Pilot Study. Metabolites 2016; 6:metabo6030026. [PMID: 27598216 PMCID: PMC5041125 DOI: 10.3390/metabo6030026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/21/2016] [Accepted: 08/30/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Shock includes different pathophysiological mechanisms not fully understood and remains a challenge to manage. Exhaled breath condensate (EBC) may contain relevant biomarkers that could help us make an early diagnosis or better understand the metabolic perturbations resulting from this pathological situation. OBJECTIVE we aimed to establish the metabolomics signature of EBC from patients in shock with acute respiratory failure in a pilot study. MATERIAL AND METHODS We explored the metabolic signature of EBC in 12 patients with shock compared to 14 controls using LC-HRMS. We used a non-targeted approach, and we performed a multivariate analysis based on Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA) to differentiate between the two groups of patients. RESULTS We optimized the procedure of EBC collection and LC-HRMS detected more than 1000 ions in this fluid. The optimization of multivariate models led to an excellent model of differentiation for both groups (Q2 > 0.4) after inclusion of only 6 ions. DISCUSSION AND CONCLUSION We validated the procedure of EBC collection and we showed that the metabolome profile of EBC may be relevant in characterizing patients with shock. We performed well in distinguishing these patients from controls, and the identification of relevant compounds may be promising for ICC patients.
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Affiliation(s)
- Brice Fermier
- Department of Anesthesiology and Intensive Care, CHRU Tours Bretonneau, 2 boulevard Tonnellé, 37044 Tours cedex 9, France.
| | - Hélène Blasco
- Laboratoire de Biochimie et Biologie Moléculaire, CHRU Bretonneau, 2, boulevard Tonnellé, 37044 Tours cedex 9, France.
- INSERM U930, équipe Neurogenetics and Neurometabolomics, Université François Rabelais, 10 bd Tonnellé, 37000 Tours, France.
| | - Emmanuel Godat
- Department of Anesthesiology and Intensive Care, CHRU Tours Bretonneau, 2 boulevard Tonnellé, 37044 Tours cedex 9, France.
| | - Cinzia Bocca
- PPF, Université François Rabelais, 10 bd tonnellé, 37000 Tours, France.
| | - Joseph Moënne-Loccoz
- Department of Anesthesiology and Intensive Care, CHRU Tours Bretonneau, 2 boulevard Tonnellé, 37044 Tours cedex 9, France.
| | - Patrick Emond
- INSERM U930, équipe Neurogenetics and Neurometabolomics, Université François Rabelais, 10 bd Tonnellé, 37000 Tours, France.
- PPF, Université François Rabelais, 10 bd tonnellé, 37000 Tours, France.
| | - Christian R Andres
- Laboratoire de Biochimie et Biologie Moléculaire, CHRU Bretonneau, 2, boulevard Tonnellé, 37044 Tours cedex 9, France.
- INSERM U930, équipe Neurogenetics and Neurometabolomics, Université François Rabelais, 10 bd Tonnellé, 37000 Tours, France.
| | - Marc Laffon
- Department of Anesthesiology and Intensive Care, CHRU Tours Bretonneau, 2 boulevard Tonnellé, 37044 Tours cedex 9, France.
| | - Martine Ferrandière
- Department of Anesthesiology and Intensive Care, CHRU Tours Bretonneau, 2 boulevard Tonnellé, 37044 Tours cedex 9, France.
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Blasco H, Vourc'h P, Pradat PF, Gordon PH, Andres CR, Corcia P. Further development of biomarkers in amyotrophic lateral sclerosis. Expert Rev Mol Diagn 2016; 16:853-68. [PMID: 27275785 DOI: 10.1080/14737159.2016.1199277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Amyotrophic lateral sclerosis (ALS) is an idiopathic neurodegenerative disease usually fatal in less than three years. Even if standard guidelines are available to diagnose ALS, the mean diagnosis delay is more than one year. In this context, biomarker discovery is a priority. Research has to focus on new diagnostic tools, based on combined explorations. AREAS COVERED In this review, we specifically focus on biology and imaging markers. We detail the innovative field of 'omics' approach and imaging and explain their limits to be useful in routine practice. We describe the most relevant biomarkers and suggest some perspectives for biomarker research. Expert commentary: The successive failures of clinical trials in ALS underline the need for new strategy based on innovative tools to stratify patients and to evaluate their responses to treatment. Biomarker data may be useful to improve the designs of clinical trials. Biomarkers are also needed to better investigate disease pathophysiology, to identify new therapeutic targets, and to improve the performance of clinical assessments for diagnosis and prognosis in the clinical setting. A consensus on the best management of neuroimaging and 'omics' methods is necessary and a systematic independent validation of findings may add robustness to future studies.
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Affiliation(s)
- H Blasco
- a UMR INSERM U930 , Université François-Rabelais de Tours , Tours , France.,b Laboratoire de Biochimie et de Biologie Moléculaire , Hôpital Bretonneau, CHRU de Tours , Tours , France
| | - P Vourc'h
- a UMR INSERM U930 , Université François-Rabelais de Tours , Tours , France.,b Laboratoire de Biochimie et de Biologie Moléculaire , Hôpital Bretonneau, CHRU de Tours , Tours , France
| | - P F Pradat
- c Département des Maladies du Système Nerveux, Assistance Publique-Hôpitaux de Paris , Hôpital de la Salpêtrière , Paris , France.,d Sorbonne Universités, UPMC Université Paris 06, CNRS, INSERM , Laboratoire d'Imagerie Biomédicale , Paris , France
| | - P H Gordon
- e Neurology Unit, Northern Navajo Medical Center , Shiprock , NM , USA
| | - C R Andres
- a UMR INSERM U930 , Université François-Rabelais de Tours , Tours , France.,b Laboratoire de Biochimie et de Biologie Moléculaire , Hôpital Bretonneau, CHRU de Tours , Tours , France
| | - P Corcia
- a UMR INSERM U930 , Université François-Rabelais de Tours , Tours , France.,b Laboratoire de Biochimie et de Biologie Moléculaire , Hôpital Bretonneau, CHRU de Tours , Tours , France.,f Centre SLA , Service de Neurologie et Neurophysiologie Clinique, CHRU de Tours , Tours , France
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Theodorsson E. Quality Assurance in Clinical Chemistry: A Touch of Statistics and A Lot of Common Sense. J Med Biochem 2016; 35:103-112. [PMID: 28356868 PMCID: PMC5346785 DOI: 10.1515/jomb-2016-0012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 02/23/2016] [Indexed: 12/23/2022] Open
Abstract
Working in laboratories of clinical chemistry, we risk feeling that our personal contribution to quality is small and that statistical models and manufacturers play the major roles. It is seldom sufficiently acknowledged that personal knowledge, skills and common sense are crucial for quality assurance in the interest of patients. The employees, environment and procedures inherent to the laboratory including its interactions with the clients are crucial for the overall result of the total testing chain. As the measurement systems, reagents and procedures are gradually improved, work on the preanalytical, postanalytical and clinical phases is likely to pay the most substantial dividends in accomplishing further quality improvements. This means changing attitudes and behaviour, especially of the users of the laboratory. It requires understanding people and how to engage them in joint improvement processes. We need to use our knowledge and common sense expanded with new skills e.g. from the humanities, management, business and change sciences in order to bring this about together with the users of the laboratory.
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Affiliation(s)
- Elvar Theodorsson
- Department of Clinical Chemistry and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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Hare DJ, New EJ. On the outside looking in: redefining the role of analytical chemistry in the biosciences. Chem Commun (Camb) 2016; 52:8918-34. [DOI: 10.1039/c6cc00128a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Analytical chemistry has much to offer to an improved understanding of biological systems.
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Affiliation(s)
- Dominic J. Hare
- Elemental Bio-imaging Facility
- University of Technology Sydney
- Broadway
- Australia
- The Florey Institute of Neuroscience and Mental Health
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Abstract
Clinical chemistry uses automated measurement techniques and medical knowledge in the interest of patients and healthy subjects. Automation has reduced repeatability and day-to-day variation considerably. Bias has been reduced to a lesser extent by reference measurement systems. It is vital to minimize clinically important bias, in particular bias within conglomerates of laboratories that measure samples from the same patients. Small and variable bias components will over time show random error properties and conventional random-error based methods for calculating measurement uncertainty can then be applied. The present overview of bias presents the general principles of error and uncertainty concepts, terminology and analysis, and suggests methods to minimize bias and measurement uncertainty in the interest of healthcare.
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Garelnabi M, Younis A. Paraoxonase-1 enzyme activity assay for clinical samples: validation and correlation studies. Med Sci Monit 2015; 21:902-8. [PMID: 25814092 PMCID: PMC4381856 DOI: 10.12659/msm.892668] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Paraoxonase-1 (PON1) enzyme is reported in various types of tissues and linked to numerous pathophysiological disorders. It is a potential biomarker in many pathological conditions such as cardiovascular diseases. MATERIAL AND METHODS We conducted several small-scale studies to evaluate PON1 performance as affected by sample types, storage, and interferences. We also carried out short-term studies to compare the performance of the widely used PON1 assay to the similar commercially available PON1 kit assay method; sample size for the method comparison was N=40, and the number varied for other validation experiments. RESULTS Our studies using various types of anticoagulants show that samples collected in tubes with NaF, citrate, EDTA, clot activator, and sodium heparin have increased PON1 levels that are 49%, 24.5%, 19.8%, 11.4%, and 8%, respectively, higher compared to serum samples collected in plain tubes. However, samples collected in lithium heparin tubes demonstrated 10.4% lower PON1 levels compared to serum collected in plain tubes. Biological interference such as hemolysis has little effect on PON1 levels; however, samples spiked with lipids have shown 13% lower PON 1 levels. Our studies comparing the PON1 method commonly available for PON1 assay and a similar non-ELISA commercially available PON1 kit method showed a weak Spearman correlation coefficient of R2=0.40 for the range of 104.9-245.6 U/L. CONCLUSIONS The current study provides new validation data on enzyme PON1 performance. While no appreciable change was seen with storage, samples type affects the enzyme performance. Our results should encourage additional clinical studies to investigate other aspects of factors known to affect PON1 enzyme function and performance.
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Affiliation(s)
- Mahdi Garelnabi
- Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts, Lowell, MA, USA
| | - Abdelmoneim Younis
- Department of Obstetrics and Gynecology, Mercer University School of Medicine & Central Georgia Fertility Institute, Macon, GA, USA
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A rapid multidimensional GC–flame-ionization detector method for determination of fatty acid methyl esters. Bioanalysis 2014; 6:477-84. [DOI: 10.4155/bio.13.305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Background: Fatty acids play important roles in the pathogenesis of many diseases. In order to investigate a wide spectrum of fatty acids in biological matrix, we developed an approach for quantitative analysis of fatty acids based on a heart-cutting 2D gas chromatographic-flame ionization detector system. Results: This system uses a Dean Switch interface between the primary polar and secondary nonpolar capillary column. Most of the standards were separated by the primary column. Unresolved components are selectively transferred to the secondary column, where they are completely separated. This method was further evaluated using plasma obtained from 11 healthy and 11 chronic coronary artery disease patients. Conclusion: Our results prove that this approach is sensitive, precise and specific, capable of measuring 37 specific fatty acids. It indicates that this approach offers a reliable and sensitive technical platform for comprehensive quantification of fatty acids.
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The first 5 years of Bioanalysis: a story of growth and evolution. Bioanalysis 2013; 5:2975-80. [PMID: 24320122 DOI: 10.4155/bio.13.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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de Macedo AN, Jiwa MIY, Macri J, Belostotsky V, Hill S, Britz-McKibbin P. Strong anion determination in biological fluids by capillary electrophoresis for clinical diagnostics. Anal Chem 2013; 85:11112-20. [PMID: 24127785 DOI: 10.1021/ac402975q] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
New methods for quantitative analysis of strong anions are required for diagnostic testing of human diseases. Current techniques suffer from poor selectivity and/or long analysis times that are not amenable for labile anions in high-saline or volume-restricted samples. We introduce a rapid assay (<5 min) based on capillary electrophoresis (CE) with indirect UV detection for simultaneous analysis of sulfate, sulfite, and chloride in human urine, plasma, and sweat specimens. Remarkable selectivity for strong anions is achieved by using an acidic background electrolyte under reversed polarity that results in electrokinetic rejection of matrix interferences at the capillary inlet. A dual co-ion probe system consisting of 5 mM naphthalene disulfonate (NDS) and 5 mM naphthalene trisulfonate (NTS) in 0.4 M formic acid, pH 2.0 is developed for detection of UV transparent anions (S/N ≈ 3, 60 μM with a 25 μm inner diameter fused-silica capillary) with good peak symmetry and baseline stability. Due to the chemical reactivity of sulfite, dilute formaldehyde is used as a reagent to form an acid-stable hydroxymethylsulfonate adduct. Method validation confirmed excellent linearity (R(2) > 0.999), good accuracy (mean bias ≈7%), and acceptable long-term reproducibility (CV < 10%) over 20 days. The assay allows for artifact-free determination of sulfate and sulfite with consistent results for chloride when compared to standard electrochemical methods (R(2) > 0.975). Preliminary data suggest that kidney-stone formers have lower urinary sulfate excretion relative to non-kidney-stone patient controls (p = 0.0261). CE offers a selective yet robust platform for routine analysis of strong anions that is needed for confirmatory testing of cystic fibrosis, sulfite oxidase deficiency, urolithiasis, and other disorders of sulfur metabolism and/or anion transport.
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Affiliation(s)
- Adriana Nori de Macedo
- Department of Chemistry and Chemical Biology, ‡Department of Pathology and Molecular Medicine, §Department of Pediatrics, McMaster University , 1280 Main Street West, Hamilton, ON L8S4M1, Canada
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Blasco H, Corcia P, Gordon PH, Pradat PF. Biological and neuroimaging biomarkers for amyotrophic lateral sclerosis: 2013 and beyond. Neurodegener Dis Manag 2013. [DOI: 10.2217/nmt.13.43] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
SUMMARY Amyotrophic lateral sclerosis is an idiopathic, incurable neurodegenerative disease that is fatal for most patients in less than 3 years from the time weakness first appears. Alongside identification of etiologies and stronger neuroprotective agents, the development of biomarkers is a main research priority. Since the original description, diagnosis and progression measurement in amyotrophic lateral sclerosis has been clinical. The time from symptom onset to diagnosis is usually more than a year, and clinical research studies utilize clinical end points that have low sensitivity. Few eligible patients and inefficient trials mean that just one or a few new therapies can be tested each year. Biological markers are needed not only to improve the sensitivity of clinical assessments, but also to better examine disease pathophysiology in vivo.
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Affiliation(s)
- Hélène Blasco
- UMR INSERM U930, Université François-Rabelais de Tours, Tours, France
- Laboratoire de Biochimie & de Biologie Moléculaire, Hôpital Bretonneau, CHRU de Tours, France
| | - Philippe Corcia
- Centre SLA, Service de Neurologie & Neurophysiologie Clinique, CHRU de Tours, France
| | - Paul H Gordon
- Départment des Maladies du Système Nerveux, Assistance Publique-Hôpitaux de Paris, Hôpital de la Salpêtrière, 75013, Paris, France
| | - Pierre-François Pradat
- Départment des Maladies du Système Nerveux, Assistance Publique-Hôpitaux de Paris, Hôpital de la Salpêtrière, 75013, Paris, France
- UMR-678, INSERM-UPMC, Hôpital de la Salpêtrière, 75013, Paris, France
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