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Panteghini M. An improved implementation of metrological traceability concepts is needed to benefit from standardization of laboratory results. Clin Chem Lab Med 2024; 0:cclm-2024-0428. [PMID: 38687497 DOI: 10.1515/cclm-2024-0428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 04/12/2024] [Indexed: 05/02/2024]
Abstract
Non-harmonization of laboratory results represents a concrete risk for patient safety. To avoid harms, it is agreed that measurements by in vitro diagnostic medical devices (IVD-MD) on clinical samples should be traceable to higher-order references and adjusted to give the same result. However, metrological traceability is not a formal claim and has to be correctly implemented, which in practice does not happen for a non-negligible number of measurands. Stakeholders, such as higher-order reference providers, IVD manufacturers, and External Quality Assessment organizers, have major responsibilities and should improve their contribution by unambiguously and rigorously applying what is described in the International Organization for Standardization 17511:2020 standard and other documents provided by the international scientific bodies, such as Joint Committee on Traceability in Laboratory Medicine and IFCC. For their part, laboratory professionals should take responsibility to abandon non-selective methods and move to IVD-MDs displaying proper selectivity, which is one of the indispensable prerequisites for the correct implementation of metrological traceability. The practicality of metrological traceability concepts is not impossible but relevant education and appropriate training of all involved stakeholders are essential to obtain the expected benefits in terms of standardization.
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Affiliation(s)
- Mauro Panteghini
- Department of Laboratory Medicine, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Torun, Poland
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2
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Zhou X, Liu Z, Ma Y, Zhang C, Wu Y. A mathematical algorithm to harmonize measurements for thyroid-stimulating hormone between instruments. Clin Chim Acta 2023; 548:117513. [PMID: 37562523 DOI: 10.1016/j.cca.2023.117513] [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: 05/15/2023] [Revised: 07/24/2023] [Accepted: 08/07/2023] [Indexed: 08/12/2023]
Abstract
BACKGROUND Thyroid-stimulating hormone (TSH) is measured differently between diagnostic units using different devices, which makes cross-comparisons challenging. Here, we have developed a mathematical algorithm to harmonize TSH measurements between 2 instruments, the Abbott ISR2000 and the Siemens ADVIA Centaur XP. METHODS Applying the principle of the maximum allowable error between the standard curve and real signal values, the minimum number of comparison samples required for TSH hormone detection was calculated for both instruments. Next, a mathematical algorithm describing the relationship between TSH standard curves from both instruments was established. The algorithm was then tested on sample measurements from both instruments, with signals transformed to Siemens ADVIA Centuar XP-type data. Finally, test results were assessed where the relative error was RESULTS Before conversion, the mean percentage error between the TSH results of samples measured on both instruments was 23.20% (>1/2 TEa). After algorithmic transformation, the average percentage error was reduced to 7.93% (<1/2 TEa). CONCLUSIONS Our algorithm enables TSH measurements across different instruments to be comparable, and provides a method to harmonize TSH data between laboratories that utilize different instrumentation.
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Affiliation(s)
- Xin Zhou
- Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu 610041, China; Jintang First People's Hospital, Chengdu 610400, China
| | - Zaishuan Liu
- Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yining Ma
- College of Mathematics of Sichuan University, Chengdu 610065, China
| | - Chongwei Zhang
- Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Yongkang Wu
- Department of Laboratory Medicine, West China Hospital of Sichuan University, Chengdu 610041, China; Jintang First People's Hospital, Chengdu 610400, China.
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3
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D'Aurizio F, Kratzsch J, Gruson D, Petranović Ovčariček P, Giovanella L. Free thyroxine measurement in clinical practice: how to optimize indications, analytical procedures, and interpretation criteria while waiting for global standardization. Crit Rev Clin Lab Sci 2023; 60:101-140. [PMID: 36227760 DOI: 10.1080/10408363.2022.2121960] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Thyroid dysfunctions are among the most common endocrine disorders and accurate biochemical testing is needed to confirm or rule out a diagnosis. Notably, true hyperthyroidism and hypothyroidism in the setting of a normal thyroid-stimulating hormone level are highly unlikely, making the assessment of free thyroxine (FT4) inappropriate in most new cases. However, FT4 measurement is integral in both the diagnosis and management of relevant central dysfunctions (central hypothyroidism and central hyperthyroidism) as well as for monitoring therapy in hyperthyroid patients treated with anti-thyroid drugs or radioiodine. In such settings, accurate FT4 quantification is required. Global standardization will improve the comparability of the results across laboratories and allow the development of common clinical decision limits in evidence-based guidelines. The International Federation of Clinical Chemistry and Laboratory Medicine Committee for Standardization of Thyroid Function Tests has undertaken FT4 immunoassay method comparison and recalibration studies and developed a reference measurement procedure that is currently being validated. However, technical and implementation challenges, including the establishment of different clinical decision limits for distinct patient groups, still remain. Accordingly, different assays and reference values cannot be interchanged. Two-way communication between the laboratory and clinical specialists is pivotal to properly select a reliable FT4 assay, establish reference intervals, investigate discordant results, and monitor the analytical and clinical performance of the method over time.
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Affiliation(s)
- Federica D'Aurizio
- Department of Laboratory Medicine, University Hospital of Udine, Udine, Italy
| | - Jürgen Kratzsch
- Institute for Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital, University of Leipzig, Leipzig, Germany
| | - Damien Gruson
- Department of Clinical Biochemistry, Cliniques Universitaires St-Luc and Université Catholique de Louvain, Brussels, Belgium
| | - Petra Petranović Ovčariček
- Department of Oncology and Nuclear Medicine, University Hospital Center Sestre milosrdnice, Zagreb, Croatia
| | - Luca Giovanella
- Clinic for Nuclear Medicine and Competence Center for Thyroid Diseases, Imaging Institute of Southern Switzerland, Ente Ospedaliero Cantonale, Bellinzona, Switzerland.,Clinic for Nuclear Medicine and Thyroid Center, University and University Hospital of Zurich, Zurich, Switzerland
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4
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Braga F, Pasqualetti S, Frusciante E, Borrillo F, Chibireva M, Panteghini M. Harmonization Status of Serum Ferritin Measurements and Implications for Use as Marker of Iron-Related Disorders. Clin Chem 2022; 68:1202-1210. [PMID: 35794075 DOI: 10.1093/clinchem/hvac099] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/06/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Serum ferritin is considered a suitable biomarker of iron-related disorders. However, data about the comparability of results among commercial measuring systems (MSs) are contradictory. We performed an intercomparison study aimed at verifying the current interassay variability and its impact on clinical application of the test. Obtaining this information is vital because manufacturers continue to claim calibration alignment to different WHO preparations, which are not related to each other in terms of traceability. METHODS Four widely used MSs were evaluated. The interassay agreement was verified using 39 human serum pools. The recovery of WHO International Standard (IS) 94/572 (the only reference material available at the time of the study) was evaluated, after assessing the material commutability. Finally, an approach for harmonizing ferritin results was proposed. RESULTS Highly significant differences (P < 0.00001) among ferritin concentrations assayed by different MSs were detected and the interassay CV (median 22.9%; interquartile range 21.8-25.5) overlapped the desirable intermethod bias (24.6%). IS 94/572 was commutable for use only with Access and Centaur, with Access being the only MS correctly recovering its assigned value. Accordingly, we used regression data against Access to recalibrate MSs, indirectly aligning them to IS 94/572, with a substantial improvement in degree of harmonization and traceability to higher-order reference. CONCLUSIONS The harmonization among evaluated ferritin MSs is far from optimal, with the implementation of traceability to different WHO ISs being a factor of confusion. A recalibration approach, however, would permit measurement harmonization, allowing the use of common decision thresholds.
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Affiliation(s)
- Federica Braga
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università degli Studi di Milano, Milan, Italy
| | - Sara Pasqualetti
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università degli Studi di Milano, Milan, Italy
| | - Erika Frusciante
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università degli Studi di Milano, Milan, Italy
| | - Francesca Borrillo
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università degli Studi di Milano, Milan, Italy
| | - Mariia Chibireva
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università degli Studi di Milano, Milan, Italy
| | - Mauro Panteghini
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università degli Studi di Milano, Milan, Italy
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5
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DePalma RG, Hayes VW, O'Leary TJ. Optimal serum ferritin level range: iron status measure and inflammatory biomarker. Metallomics 2021; 13:6287580. [PMID: 34048587 PMCID: PMC8195161 DOI: 10.1093/mtomcs/mfab030] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 12/19/2022]
Abstract
This report provides perspectives concerning dual roles of serum ferritin as a measure of both iron status and inflammation. We suggest benefits of a lower range of serum ferritin as has occurred for total serum cholesterol and fasting blood glucose levels. Observations during a prospective randomized study using phlebotomy in patients with peripheral arterial disease offered unique insights into dual roles of serum ferritin both as an iron status marker and acute phase reactant. Robust positive associations between serum ferritin, interleukin 6 [IL-6], tissue necrosis factor-alpha, and high sensitivity C-reactive protein were discovered. Elevated serum ferritin and IL-6 levels associated with increased mortality and with reduced mortality at ferritin levels <100 ng mL-1. Epidemiologic studies demonstrate similar outcomes. Extremely elevated ferritin and IL-6 levels also occur in individuals with high mortality due to SARS-CoV-2 infection. Disordered iron metabolism reflected by a high range of serum ferritin level signals disease severity and outcomes. Based upon experimental and epidemiologic data, we suggest testing the hypotheses that optimal ferritin levels for cardiovascular mortality reduction range from 20 to 100 ng mL-1 with % transferrin levels from 20 to 50%, to ensure adequate iron status and that ferritin levels above 194 ng mL-1 associate with all-cause mortality in population cohorts.
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Affiliation(s)
- Ralph G DePalma
- Office of Research and Development, Department of Veterans Affairs, Washington, DC 20420, USA.,Department of Surgery, Uniformed University of the Health Sciences, Bethesda, MD 20814, USA
| | - Virginia W Hayes
- Virginia W Hayes, Ambulatory Care Service, Sierra Nevada Health Care System, Reno, NV 89502, USA
| | - Timothy J O'Leary
- Office of Research and Development, Department of Veterans Affairs, Washington, DC 20420, USA.,Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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6
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Zhang S, Cheng F, Wang H, Wen J, Zeng J, Zhang C, Liu W, Wang N, Jia T, Wang M, Zhang R, Yue Y, Xu J, Wang Z, Li Y, Chen W, Wang Q. Comparability of thyroid-stimulating hormone immunoassays using fresh frozen human sera and external quality assessment data. PLoS One 2021; 16:e0253324. [PMID: 34129644 PMCID: PMC8205121 DOI: 10.1371/journal.pone.0253324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/03/2021] [Indexed: 12/04/2022] Open
Abstract
Background This study aimed to assess the comparability among assays using freshly frozen human sera and external quality assessment (EQA) data in China. Methods Twenty-nine serum samples and two commercial EQA materials, obtained from the National Center for Clinical Laboratories (NCCL), were analyzed in triplicate using eight routine TSH assays. The commutability of commercial EQA materials (NCCL materials) was evaluated in accordance with the CLSI EP30-A and IFCC bias analysis. Median values obtained for the NCCL EQA materials were used to determine the systematic and commutability-related biases among immunoassays through back-calculation. The comparability of TSH measurements from a panel of clinical samples and NCCL EQA data was determined on the basis of Passing–Bablok regression. Furthermore, human serum pools were used to perform commutable EQA. Results NCCL EQA materials displayed commutability among three or five of seven assay combinations according CLSI or IFCC approach, respectively. The mean of systematic bias ranged from -13.78% to 9.85% for the eight routine TSH assays. After correcting for systematic bias, averaged commutability-related biases ranged between -42.26% and 12.19%. After correction for systematic and commutability -related biases, the slopes indicating interassay relatedness ranged from 0.801 to 1.299 using individual human sera, from 0.735 to 1.254 using NCCL EQA data, and from 0.729 to 1.115 using pooled human serum EQA(the commutable EQA). Conclusions The harmonization of TSH measurement is challenging; hence, systematic and commutability-related biases should be determined and corrected for accurate comparisons among assays when using human individual serum and the commercial EQA materials.
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Affiliation(s)
- Shunli Zhang
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Fei Cheng
- Department of Clinical Laboratory, Wangjing Hospital, China Academy of Traditional Chinese Medicine, Beijing, P.R. China
| | - Hua Wang
- Department of Clinical Laboratory, China-Japan Friendship Hospital, Beijing, P.R. China
| | - Jiangping Wen
- Department of Clinical Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, P.R. China
| | - Jie Zeng
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing Engineering Research Center of Laboratory Medicine, Beijing, P.R. China
| | - Chuanbao Zhang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing Engineering Research Center of Laboratory Medicine, Beijing, P.R. China
| | - Wensong Liu
- Department of Clinical Laboratory, Beijing Hospital, Beijing, P.R. China
| | - Ning Wang
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Tingting Jia
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Mo Wang
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Rui Zhang
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Yuhong Yue
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Jing Xu
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Zhanyong Wang
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
| | - Yilong Li
- Department of Clinical Laboratory, Beijing Hospital, Beijing, P.R. China
| | - Wenxiang Chen
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology, Beijing Engineering Research Center of Laboratory Medicine, Beijing, P.R. China
- * E-mail: (WC); (QW)
| | - Qingtao Wang
- Department of Clinical Laboratory, Beijing Chaoyang Hospital, Beijing Center for Clinical Laboratories, The Third Clinical Medical College of Capital Medical University, Beijing, P.R. China
- * E-mail: (WC); (QW)
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7
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Bohn MK, Horn P, League D, Steele P, Hall A, Adeli K. Pediatric reference intervals for endocrine markers and fertility hormones in healthy children and adolescents on the Siemens Healthineers Atellica immunoassay system. Clin Chem Lab Med 2021; 59:1421-1430. [PMID: 33957708 DOI: 10.1515/cclm-2021-0050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/25/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Rapid development in childhood and adolescence combined with lack of immunoassay standardization necessitates the establishment of age-, sex-, and assay-specific reference intervals for immunochemical markers. This study established reference intervals for 11 immunoassays on the new Siemens Healthineers Atellica® IM Analyzer in the healthy CALIPER cohort. METHODS A total of 600 healthy participants (birth to 18 years) were recruited from the community, and serum samples were collected with informed consent. After sample analysis, age- and sex-specific differences were assessed, and outliers were removed. Reference intervals were established using the robust method (40-<120 participants) or nonparametric method (≥120 participants). RESULTS Of the 11 immunoassays studied, nine required age partitioning (i.e., dehydroepiandrosterone-sulfate, estradiol, ferritin, folate, follicle-stimulating hormone, luteinizing hormone, progesterone, testosterone, vitamin B12), and seven required sex partitioning. Free thyroxine and thyroid-stimulating hormone demonstrated no significant age- and/or sex-specific differences. CONCLUSIONS Overall, the age- and sex-specific trends observed closely mirrored those previously reported by CALIPER on other platforms as well as other internationally recognized studies. However, established lower and upper limits demonstrated some discrepancies between published values from healthy cohorts on alternate analytical systems, highlighting differences between manufacturers and the need for platform-specific reference intervals for informed pediatric clinical decision-making.
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Affiliation(s)
- Mary Kathryn Bohn
- CALIPER Program, Department of Pediatric Laboratory Medicine, Hospital for Sick Children, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Paul Horn
- Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Donna League
- Siemens Healthcare Diagnostics Inc., Tarrytown, NY, USA
| | - Paul Steele
- Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Alexandra Hall
- CALIPER Program, Department of Pediatric Laboratory Medicine, Hospital for Sick Children, Toronto, ON, Canada
| | - Khosrow Adeli
- CALIPER Program, Department of Pediatric Laboratory Medicine, Hospital for Sick Children, Toronto, ON, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
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8
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Snozek CLH, Kaleta EJ, Bryant SC, Baumann NA. What to do when the gold standard isn't accessible? Clin Biochem 2021; 92:87-88. [PMID: 33794194 DOI: 10.1016/j.clinbiochem.2021.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/27/2022]
Affiliation(s)
- Christine L H Snozek
- Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, 13400 E Shea Boulevard, Scottsdale, AZ 85259, USA.
| | - Erin J Kaleta
- Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, 13400 E Shea Boulevard, Scottsdale, AZ 85259, USA
| | - Sandra C Bryant
- Division of Biomedical Statistics and Informatics, Mayo Clinic Rochester, 200 1(st) Street SW, Rochester, MN 55905, USA
| | - Nikola A Baumann
- Department of Laboratory Medicine and Pathology, Mayo Clinic Rochester, 200 1(st) Street SW, Rochester, MN 55905, USA
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9
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Zhang R, Wang Q. Comparability of four clinical laboratory measurement methods for GGT and commutability of candidate reference materials. J Clin Lab Anal 2020; 34:e23557. [PMID: 32914473 PMCID: PMC7755790 DOI: 10.1002/jcla.23557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 12/30/2022] Open
Abstract
Background This study was conducted to evaluate the progress in the standardization of the gamma‐glutamyl transferase (GGT) to achieve metrological traceability of routine in vitro diagnosis (IVD) medical devices. Methods We collected 25 single fresh frozen serum samples for GGT analysis. Candidate reference materials (RMs), calibrators, internal quality controls (IQC), and external quality assessment (EQA) materials from the National Center for Clinical Laboratory (NCCL), Beijing Center for Clinical Laboratory (BCCL), and College of American Pathologists (CAP) were randomly added to these serum samples. A total of 42 samples were examined using IFCC reference method and four different IVD medical devices to perform the comparability and commutability study. Results The four IVD medical devices achieved trueness assessment within the measurement range. Linear analysis showed the agreement of Siemens ADVIA 2400, Hitachi 7600‐020/BioSino, Beckman AU 5800, and Roche Cobas 501 with the reference method. These assay pairs were comparable at the medical decision levels. The GGT in‐house candidate RMs, and Beckmann and Roche calibrators were all within the limits of the 95% prediction intervals, the commutability of BioSino calibrators was indeterminate, and some internal and external quality controls were not commutable for comparisons of certain IVD medical devices vs the reference method. Conclusions By comparing with the reference method, we found that performance of GGT conventional measurement systems to be traceable to the higher order references was improved. The commutable materials for calibration and trueness controls of routine methods were significant to promote the standardization of GGT analysis.
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Affiliation(s)
- Rui Zhang
- Department of Clinical Laboratory, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China
| | - Qingtao Wang
- Department of Clinical Laboratory, Beijing Chao-yang Hospital, Capital Medical University, Beijing, China.,Beijing Center for Clinical Laboratories, Beijing, China
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10
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Braga F, Frusciante E, Ferraro S, Panteghini M. Trueness evaluation and verification of inter-assay agreement of serum folate measuring systems. Clin Chem Lab Med 2020; 58:1697-1705. [PMID: 31926068 DOI: 10.1515/cclm-2019-0928] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 12/12/2019] [Indexed: 11/15/2022]
Abstract
Background Definitive data to establish if the use of the WHO International Standard (IS) 03/178 as a common calibrator of commercial measuring systems (MSs) has improved the harmonization of serum total folate (tFOL) measurements to a clinically suitable level are lacking. Here, we report the results of an intercomparison study aimed to verify if the current inter-assay variability is acceptable for clinical application of tFOL testing. Methods After confirming their commutability, the IS 03/178 and National Institute for Standards and Technology SRM 3949 L1 were used for evaluating the correctness of traceability implementation by manufacturers and the MSs trueness, respectively. The inter-assay agreement was verified using 20 patient pools. The measurement uncertainty (U) of tFOL measurements on clinical samples was also estimated. An outcome-based model for defining desirable performance specifications for bias and imprecision for serum tFOL measurements was applied. Results The majority of evaluated MSs overestimated the WHO IS value of +5% or more with the risk to produce an unacceptably high number of false-negative results in clinical practice. The mean inter-assay CV on all pools and on those with tFOL values >3.0 μg/L (n = 15) was 12.5% and 7.1%, respectively. In neither case the goal of 3.0% was fulfilled. The residual bias resulted in an excessive U of tFOL measurement on clinical samples. Conclusions The implementation of traceability of tFOL MSs to the WHO IS 03/178 is currently inadequate, resulting in an inter-assay variability that does not permit the use of a common threshold for detecting folate deficiency.
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Affiliation(s)
- Federica Braga
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Università di Milano, Milan, Italy.,UOC Patologia Clinica, ASST Fatebenfratelli Sacco, via GB Grassi 74, 20157 Milano, Italy, Phone: +390239042743, E-mail:
| | - Erika Frusciante
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Milano, Italy
| | - Simona Ferraro
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Milano, Italy
| | - Mauro Panteghini
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), Milano, Italy
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11
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Isaksen JL, Skov MW, Graff C, Ellervik C, Kanters JK. Electrocardiography in euthyroid individuals: a Danish general population study. Minerva Endocrinol (Torino) 2020; 47:103-110. [PMID: 32720496 DOI: 10.23736/s2724-6507.20.03170-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Thyroid hormones within the euthyroid range have been linked to mortality and differences in heart rate. However, some relations between thyroid hormone concentration and various electrocardiographic measurements remain unassessed. We aimed to investigate the association between thyroid hormone concentrations within the euthyroid range and different electrocardiographic markers in people free of thyroid disease. METHODS We obtained electrocardiograms (ECG) and blood samples of free T4, total T3, and thyrotropin (TSH) in 20,852 subjects from the general population (the GESUS study). Relations between concentrations of TSH, free T4, and total T3 and heart rate, QTc, QRS duration, PR interval, P-wave duration and T-wave morphology were assessed in a multivariate adjusted linear model stratified by sex. RESULTS Roughly half of the 18,046 included participants with thyroid hormone measurements within euthyroid range were men, and the average age was 56 years. Heart rate increased with concentrations of T3 (6.4 bpm/nM, P<0.001 in women and 5.3 bpm/nM, P<0.001 in men) and T4 (3.7 bpm/10pM, P<0.001 in women and 3.1 bpm/10pM, P<0.001 in men). We found no relation between TSH and heart rate. PR interval and QRS duration decreased with higher concentrations of T3 (all P<0.01). QTc increased with higher concentrations of T4 in men (5 ms/10pM), and T waves were flatter, more asymmetric, and more often had notches with higher concentrations of T4 (all P≤0.01). CONCLUSIONS Thyroid hormone concentrations within the euthyroid range in people free of thyroid disease were associated with changes in the electrocardiogram in a general population.
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Affiliation(s)
- Jonas L Isaksen
- Department of Biomedical Sciences, Laboratory of Experimental Cardiology, University of Copenhagen, Copenhagen, Denmark
| | - Morten W Skov
- Department of Cardiology, Laboratory for Molecular Cardiology, The Heart Center, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Claus Graff
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Christina Ellervik
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Laboratory Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Production, Research and Innovation, Region Zealand, Sorø, Denmark
| | - Jørgen K Kanters
- Department of Biomedical Sciences, Laboratory of Experimental Cardiology, University of Copenhagen, Copenhagen, Denmark -
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12
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Cluitmans JCA, van den Ouweland JMW. Reference values of a new serum folate assay traceable to the WHO International Standard. Clin Chem Lab Med 2020; 57:e176-e178. [PMID: 30721142 DOI: 10.1515/cclm-2018-1229] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/10/2019] [Indexed: 11/15/2022]
Affiliation(s)
- Judith C A Cluitmans
- Department of Clinical Chemistry, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Jody M W van den Ouweland
- Department of Clinical Chemistry, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ Nijmegen, The Netherlands
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13
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Ferraro S, Panteghini M. Folate and vitamin B12 assays after recalibration to the WHO International Standard 03/178: making the interpretation as simple as possible, but not simpler. Clin Chem Lab Med 2019; 57:1112-1114. [PMID: 30710483 DOI: 10.1515/cclm-2019-0050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Simona Ferraro
- UOC Patologia Clinica, Ospedale "Luigi Sacco", Via GB Grassi 74, 20157 Milano, Italy.,Clinical Pathology Unit, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Mauro Panteghini
- Clinical Pathology Unit, ASST Fatebenefratelli-Sacco, Milan, Italy.,Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan, Milan, Italy
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14
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Makita N, Manaka K, Sato J, Mitani K, Nangaku M, Iiri T. Bexarotene-induced hypothyroidism: Characteristics and therapeutic strategies. Clin Endocrinol (Oxf) 2019; 91:195-200. [PMID: 30903705 DOI: 10.1111/cen.13975] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/19/2019] [Accepted: 03/19/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Central hypothyroidism (CH) is a well-known adverse effect of bexarotene treatment for cutaneous T-cell lymphoma (CTCL). While concomitant levothyroxine therapy is recommended in these cases, associations between ethnic variation or susceptibility and bexarotene-induced CH have not yet been reported. This study aimed to characterize the kinetics and dose dependency of bexarotene-induced CH in Japanese patients. DESIGN AND PATIENTS Sixty-six Japanese patients with CTCL were retrospectively investigated by evaluating thyroid function during the early phase of bexarotene therapy. RESULTS At one week after bexarotene initiation, TSH and FT4 values significantly declined. However, this effect was not bexarotene dose-dependent at least at the dose of 96-320 mg/m2 . Approximately 1 month later, 61 patients exhibited hypothyroidism at a relatively low dose of bexarotene (average 251 mg/m2 /day). Forty-five study cases showed this effect at 1 week. Simple regression analyses indicated that higher pretreatment TSH values (at a cut-off value of 1.30:73% sensitivity, 57% specificity) or lower normal (within the lower half of the reference range) pretreatment FT4 values (84% sensitivity, 57% specificity) were predictive of hypothyroidism at 1 week. The remaining 21 cases showed euthyroidism at 1 week, at which TSH values may roughly predict their thyroid function at 1 month (at a cut-off value of 0.05:100% sensitivity, 80% specificity). CONCLUSIONS Preventive treatment with levothyroxine is recommended for Japanese CTCL patients prior to bexarotene therapy. Minimally, it should be considered for patients with a pretreatment TSH above 1.30, a lower normal pretreatment FT4, or a TSH below 0.05 at 1 week.
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Affiliation(s)
- Noriko Makita
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Katsunori Manaka
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Junichiro Sato
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Koji Mitani
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Masaomi Nangaku
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
| | - Taroh Iiri
- Department of Endocrinology and Nephrology, The University of Tokyo School of Medicine, Tokyo, Japan
- Department of Pharmacology, St. Marianna University School of Medicine, Kanagawa, Japan
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15
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Braga F, Panteghini M. Commutability of reference and control materials: an essential factor for assuring the quality of measurements in Laboratory Medicine. ACTA ACUST UNITED AC 2019; 57:967-973. [DOI: 10.1515/cclm-2019-0154] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 02/25/2019] [Indexed: 11/15/2022]
Abstract
Abstract
Traceability to a common reference ensures equivalence of results obtained by different assays. Traceability is achieved by an unbroken sequence of calibrations, using reference materials (RMs) that must be commutable. Using non-commutable RMs for calibration will introduce a bias in the calibrated method producing incorrect results for clinical samples (CS). Commutability was defined in 1973 as “the ability of an enzyme material to show inter-assay activity changes comparable to those of the same enzyme in human serum” and later extended as a characteristic of all RMs. However, the concept is still poorly understood and appreciated. Commutability assessment has been covered in CLSI guidelines and requires: (a) selection of 20 CS spanning the relevant concentration range; (b) analysis of both RM and CS with the pair of procedures; (c) data elaboration using regression analysis and calculation if RM fall within the 95% prediction interval defined by CS. This approach has been criticized and to improve it The International Federation of Clinical Chemistry and Laboratory Medicine established a working group that recently finalized recommendations. Commutability is also a requirement for the applicability of external quality assessment (EQA) results in the evaluation of the performance of participating laboratories in terms of standardization of their measurements. Unfortunately, EQA materials are usually not validated for commutability.
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Affiliation(s)
- Federica Braga
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan , Via G.B. Grassi 74 , Milano , Italy , Phone: +39 02 39042766
| | - Mauro Panteghini
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan , Milano , Italy
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16
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Godoy A, Tabares AH. Prevalence of low folate deficiency after wheat flour supplementation - should we still measure serum folate? Hematol Transfus Cell Ther 2018; 40:305-309. [PMID: 30370407 PMCID: PMC6200696 DOI: 10.1016/j.htct.2018.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 03/28/2018] [Indexed: 11/17/2022] Open
Abstract
Objectives To determine the frequency of folic acid deficiency in consecutive serum folate determinations and to determine whether there was a significant decrease in serum folate deficiency after folate was added to wheat flour. Methods A retrospective descriptive observational study was performed of consecutive folate measurements at the Hospital Privado Universitario, Cordoba, Argentina. Results Two cohorts were analyzed: 1197 folate measurements between 2001 and 2008 (before supplementation) and 3335 folate measurements from 2009 to 2014 (after supplementation). Folate deficiency was found in 84/1197 (7%) subjects in the pre-supplementation group and in 58/3335 (1.73%) after supplementation. The prevalence of folate deficiency was 12% between 2001 and 2003 when folate was not added to flour compared to 4% in 2004-2007 (p-value < 0.0001) when folate was added to the flour but no widespread use was documented. Conclusions In the studied population, the prevalence of serum folic acid deficiency after folate supplementation was low at 1.73%. There was a significant decrease in folate deficiency after folate was added to wheat flour. Given the low prevalence of folic acid deficiency observed in this and similar studies, and the observed change with supplementation, we conclude that routine measurement of serum folate is of limited clinical use.
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Affiliation(s)
| | - Aldo Hugo Tabares
- Hospital Privado Universitario Córdoba, Córdoba, Argentina.,Instituto Universitario de Ciencias Biomédicas Córdoba (IUCBC), Córdoba, Argentina
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17
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Garcia-Casal MN, Peña-Rosas JP, Urrechaga E, Escanero JF, Huo J, Martinez RX, Lopez-Perez L. Performance and comparability of laboratory methods for measuring ferritin concentrations in human serum or plasma: A systematic review and meta-analysis. PLoS One 2018; 13:e0196576. [PMID: 29723227 PMCID: PMC5933730 DOI: 10.1371/journal.pone.0196576] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 04/16/2018] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Different laboratory methods are used to quantify ferritin concentrations as a marker of iron status. A systematic review was undertaken to assess the accuracy and comparability of the most used methods for ferritin detection. METHODS AND FINDINGS National and regional databases were searched for prospective, retrospective, sectional, longitudinal and case-control studies containing the characteristics and performance of at least one method for serum/plasma ferritin determinations in humans published to date. The analysis included the comparison between at least 2 methods detailing: sensitivity, precision, accuracy, predictive values, inter-methods adjustment, and use of international reference materials. Pooled method performance was analyzed for each method and across methods. OUTCOMES Search strategy identified 11893 records. After de-duplication and screening 252 studies were assessed, including 187 studies in the qualitative analysis and 148 in the meta-analysis. The most used methods included radiometric, nonradiometric and agglutination assays. The overall within-run imprecision for the most reported ferritin methods was 6.2±3.4% (CI 5.69-6.70%; n = 171), between-run imprecision 8.9±8.7% (CI 7.44-10.35%; n = 136), and recovery rate 95.6% (CI 91.5-99.7%; n = 94). The pooled regression coefficient was 0.985 among all methods analyzed, and 0.984 when comparing nonradiometric and radiometric methods, without statistical differences in ferritin concentration ranging from 2.3 to 1454 μμg/L. CONCLUSION The laboratory methods most used to determine ferritin concentrations have comparable accuracy and performance. Registered in PROSPERO CRD42016036222.
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Affiliation(s)
- Maria N. Garcia-Casal
- Evidence and Programme Guidance, Department of Nutrition for Health and Development, World Health Organization, Geneva, Switzerland
| | - Juan P. Peña-Rosas
- Evidence and Programme Guidance, Department of Nutrition for Health and Development, World Health Organization, Geneva, Switzerland
| | | | - Jesus F. Escanero
- Department of Pharmacology and Physiology, Faculty of Medicine, University of Zaragoza, Zaragoza, Spain
| | - Junsheng Huo
- Department of Food Science and Technology, Institute of Nutrition and Food Safety, Beijing, China
| | - Ricardo X. Martinez
- Evidence and Programme Guidance, Department of Nutrition for Health and Development, World Health Organization, Geneva, Switzerland
| | - Lucero Lopez-Perez
- Evidence and Programme Guidance, Department of Nutrition for Health and Development, World Health Organization, Geneva, Switzerland
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18
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Braga F, Pasqualetti S, Panteghini M. The role of external quality assessment in the verification of in vitro medical diagnostics in the traceability era. Clin Biochem 2018; 57:23-28. [PMID: 29428441 DOI: 10.1016/j.clinbiochem.2018.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 01/31/2018] [Accepted: 02/07/2018] [Indexed: 01/28/2023]
Abstract
Once an in-vitro diagnostic (IVD) measuring system has been marketed and introduced into daily practice, the possible sources of degradation of its performance are numerous. It is therefore essential to put in place a continuous post-market surveillance of the quality of performance of the IVD system and of the laboratories that perform measurements in clinical setting. The participation to external quality assessment (EQA) schemes that meet specific metrological criteria is central to the evaluation of performance of clinical laboratories in terms of standardization and clinical suitability of their measurements. In addition to the use of commutable materials, in this type of EQA it is necessary to assign values (and uncertainty) to them with reference procedures and to define and apply clinically permissible analytical performance specifications to substantiate the suitability of laboratory measurements in the clinical setting. Unfortunately, there are still few permanent EQA programs fully covering these requirements because some practical constraints, including technical and economic aspects, which limit their introduction. It is, however, clear that these issues should be quickly overcome, since EQA schemes are in a unique position to add substantial value to the practice of laboratory medicine, by identifying analytes that need improved harmonization and by stimulating and sustaining standardization initiatives that are needed to support clinical practice. Importantly, this will definitively help those manufacturers that produce superior products to demonstrate the superiority of those products and oblige end users (and consequently industry) to abandon assays with demonstrated insufficient quality.
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Affiliation(s)
- Federica Braga
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan, Milan, Italy.
| | - Sara Pasqualetti
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan, Milan, Italy
| | - Mauro Panteghini
- Research Centre for Metrological Traceability in Laboratory Medicine (CIRME), University of Milan, Milan, Italy
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19
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Isaacs M, Costin M, Bova R, Barrett HL, Heffernan D, Samaras K, Greenfield JR. Management of Amiodarone-Induced Thyrotoxicosis at a Cardiac Transplantation Centre. Front Endocrinol (Lausanne) 2018; 9:482. [PMID: 30186240 PMCID: PMC6113588 DOI: 10.3389/fendo.2018.00482] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/03/2018] [Indexed: 12/22/2022] Open
Abstract
Background: Amiodarone-induced thyrotoxicosis (AIT) is associated with significant morbidity and mortality, particularly in patients with cardiac failure. The aim of the study was to evaluate the management of AIT at a tertiary hospital specialising in cardiac failure and transplantation. Methods: Retrospective audit of 66 patients treated for AIT by Endocrinology (2007-2016), classified as type 1 (T1) or type 2 (T2) based on radiological criteria. Main outcome measurements were response rate to initial treatment, time to euthyroidism, and frequency/safety of thyroidectomy. Results: Mean age was 60 ± 2 years; 80% were male. Sixty-four patients commenced medical treatment: thionamides (THIO) in 23, glucocorticoids (GC) in 17 and combination (COMB) in 24. Median thyroxine (fT4) was 35.1 (31.2-46.7) in THIO, 43.1 (30.4 -60.7) in GC, and 60.0 (39.0 ->99.9) pmol/L in COMB (p = 0.01). Initial therapy induced euthyroidism in 52%: 70% THIO, 53% GC, and 33% COMB (p = 0.045) by 100 (49-167), 47 (35-61), and 53 (45-99) days, respectively (p = 0.02). A further 11% became euthyroid after transitioning from monotherapy to COMB. Thyroidectomy was undertaken in 33%. Patients who underwent thyroidectomy were younger (54 ± 3 vs. 63 ± 2 years; p = 0.03), with higher prevalence of severely impaired left ventricular function prior to diagnosis of AIT (38 vs. 18%; p = 0.08). Despite median American Society of Anaesthesiologists classification 4, no thyroidectomy patient experienced cardiorespiratory complications/death. Conclusions: Patients with AIT had limited response to medical treatment. The poorest response was observed in COMB group, likely related to greater hyperthyroidism severity. Thyroidectomy is safe in patients with severe cardiac failure if performed in a centre with cardiac anaesthetic expertise. There should be low threshold for proceeding to thyroidectomy in patients with severe AIT and/or cardiac failure.
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Affiliation(s)
- Michelle Isaacs
- Department of Endocrinology, St Vincent's Hospital Sydney, Darlinghurst, NSW, Australia
- *Correspondence: Michelle Isaacs
| | - Monique Costin
- Northern Sydney Endocrine Centre, Sydney, NSW, Australia
- Faculty of Medicine, University of Notre Dame, Sydney, NSW, Australia
- Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Ron Bova
- Faculty of Medicine, University of Notre Dame, Sydney, NSW, Australia
- Department of Ear Nose and Throat Surgery, St Vincent's Hospital Sydney, Darlinghurst, NSW, Australia
| | - Helen L. Barrett
- Department of Obstetric Medicine, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- Faculty of Medicine, University of Queensland, Brisbane, QLD, Australia
| | - Drew Heffernan
- Department of Anaesthetics, St Vincent's Hospital Sydney, Darlinghurst, NSW, Australia
| | - Katherine Samaras
- Department of Endocrinology, St Vincent's Hospital Sydney, Darlinghurst, NSW, Australia
- Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Jerry R. Greenfield
- Department of Endocrinology, St Vincent's Hospital Sydney, Darlinghurst, NSW, Australia
- Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Sydney, NSW, Australia
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20
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Kristensen GBB, Meijer P. Interpretation of EQA results and EQA-based trouble shooting. Biochem Med (Zagreb) 2017; 27:49-62. [PMID: 28392726 PMCID: PMC5382861 DOI: 10.11613/bm.2017.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/24/2016] [Indexed: 11/03/2022] Open
Abstract
Important objectives of External Quality Assessment (EQA) is to detect analytical errors and make corrective actions. The aim of this paper is to describe knowledge required to interpret EQA results and present a structured approach on how to handle deviating EQA results. The value of EQA and how the EQA result should be interpreted depends on five key points: the control material, the target value, the number of replicates, the acceptance limits and between lot variations in reagents used in measurement procedures. This will also affect the process of finding the sources of errors when they appear. The ideal EQA sample has two important properties: it behaves as a native patient sample in all methods (is commutable) and has a target value established with a reference method. If either of these two criteria is not entirely fulfilled, results not related to the performance of the laboratory may arise. To help and guide the laboratories in handling a deviating EQA result, the Norwegian Clinical Chemistry EQA Program (NKK) has developed a flowchart with additional comments that could be used by the laboratories e.g. in their quality system, to document action against deviations in EQA. This EQA-based trouble-shooting tool has been developed further in cooperation with the External quality Control for Assays and Tests (ECAT) Foundation. This flowchart will become available in a public domain, i.e. the website of the European organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM).
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Affiliation(s)
| | - Piet Meijer
- ECAT Foundation (External quality Control for Assays and Tests), Netherlands
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21
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Panteghini M, Ceriotti F, Jones G, Oosterhuis W, Plebani M, Sandberg S. Strategies to define performance specifications in laboratory medicine: 3 years on from the Milan Strategic Conference. Clin Chem Lab Med 2017; 55:1849-1856. [PMID: 29031018 DOI: 10.1515/cclm-2017-0772] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 09/05/2017] [Indexed: 11/15/2022]
Abstract
Measurements in clinical laboratories produce results needed in the diagnosis and monitoring of patients. These results are always characterized by some uncertainty. What quality is needed and what measurement errors can be tolerated without jeopardizing patient safety should therefore be defined and specified for each analyte having clinical use. When these specifications are defined, the total examination process will be "fit for purpose" and the laboratory professionals should then set up rules to control the measuring systems to ensure they perform within specifications. The laboratory community has used different models to set performance specifications (PS). Recently, it was felt that there was a need to revisit different models and, at the same time, to emphasize the presuppositions for using the different models. Therefore, in 2014 the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) organized a Strategic Conference in Milan. It was felt that there was a need for more detailed discussions on, for instance, PS for EQAS, which measurands should use which models to set PS and how to set PS for the extra-analytical phases. There was also a need to critically evaluate the quality of data on biological variation studies and further discussing the use of the total error (TE) concept. Consequently, EFLM established five Task Finish Groups (TFGs) to address each of these topics. The TFGs are finishing their activity on 2017 and the content of this paper includes deliverables from these groups.
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22
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Bietenbeck A, Thaler MA, Luppa PB, Klawonn F. Stronger Together: Aggregated Z-values of Traditional Quality Control Measurements and Patient Medians Improve Detection of Biases. Clin Chem 2017; 63:1377-1387. [DOI: 10.1373/clinchem.2016.269845] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/11/2017] [Indexed: 01/09/2023]
Abstract
Abstract
BACKGROUND
In clinical chemistry, quality control (QC) often relies on measurements of control samples, but limitations, such as a lack of commutability, compromise the ability of such measurements to detect out-of-control situations. Medians of patient results have also been used for QC purposes, but it may be difficult to distinguish changes observed in the patient population from analytical errors. This study aims to combine traditional control measurements and patient medians for facilitating detection of biases.
METHODS
The software package “rSimLab” was developed to simulate measurements of 5 analytes. Internal QC measurements and patient medians were assessed for detecting impermissible biases. Various control rules combined these parameters. A Westgard-like algorithm was evaluated and new rules that aggregate Z-values of QC parameters were proposed.
RESULTS
Mathematical approximations estimated the required sample size for calculating meaningful patient medians. The appropriate number was highly dependent on the ratio of the spread of sample values to their center. Instead of applying a threshold to each QC parameter separately like the Westgard algorithm, the proposed aggregation of Z-values averaged these parameters. This behavior was found beneficial, as a bias could affect QC parameters unequally, resulting in differences between their Z-transformed values. In our simulations, control rules tended to outperform the simple QC parameters they combined. The inclusion of patient medians substantially improved bias detection for some analytes.
CONCLUSIONS
Patient result medians can supplement traditional QC, and aggregations of Z-values are novel and beneficial tools for QC strategies to detect biases.
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Affiliation(s)
- Andreas Bietenbeck
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar der Technischen Universität München, München, Germany
| | - Markus A Thaler
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar der Technischen Universität München, München, Germany
| | - Peter B Luppa
- Institut für Klinische Chemie und Pathobiochemie, Klinikum rechts der Isar der Technischen Universität München, München, Germany
| | - Frank Klawonn
- Department of Biostatistics, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Department of Computer Science, Ostfalia University of Applied Sciences, Wolfenbüttel, Germany
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Abstract
A body of evidence collected in the last few decades demonstrates that the pre- and post-analytical phases of the testing cycle are more error-prone than the analytical phase. However, the paradigm of errors and quality in laboratory medicine has been questioned, analytical mistakes continuing to be a major cause of adverse clinical outcomes and patient harm. Although the brain-to-brain concept is widely recognized in the community of laboratory professionals, there is lack of clarity concerning the inter-relationship between the different phases of the cycle, interdependence between the pre-analytical phase and analytical quality, and the effect of the post-analytical steps on the quality of ultimate laboratory information. Analytical quality remains the "core business" of clinical laboratories, but laboratory professionals and clinicians alike should never lose sight of the fact that pre-analytical variables are often responsible for erroneous test results and that quality biospecimens are pre-requisites for a reliable analytical phase. In addition, the pressure for expert advice on test selection and interpretation of results has increased hand in hand with the ever-increasing complexity of tests and diagnostic fields. Finally, the data on diagnostic errors and inappropriate clinical decisions made due to delay or misinterpretation of laboratory data underscore the current need for greater collaboration at the clinical-laboratory interface.
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24
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Ferraro S, Panzeri A, Borille S, Szoke D, Panteghini M. Estimation of the reference interval for serum folate measured with assays traceable to the WHO International Standard. ACTA ACUST UNITED AC 2017; 55:e195-e196. [DOI: 10.1515/cclm-2016-0941] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 12/16/2016] [Indexed: 11/15/2022]
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