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Badrick T. Letter to the Editor regarding the article by Wayne J. Dimech et al. Time to address quality control processes applied to antibody testing for infectious diseases. Clin Chem Lab Med 2023; 61(2):205-212. Clin Chem Lab Med 2023; 61:e135-e136. [PMID: 36866704 DOI: 10.1515/cclm-2023-0118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 02/10/2023] [Indexed: 03/04/2023]
Affiliation(s)
- Tony Badrick
- RCPA Quality Assurance Programs, Sydney, Australia
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2
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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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3
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Simultaneous and quantitative monitoring transcription factors in human embryonic stem cell differentiation using mass spectrometry-based targeted proteomics. Anal Bioanal Chem 2021; 413:2081-2089. [PMID: 33655347 DOI: 10.1007/s00216-021-03160-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/15/2020] [Accepted: 01/06/2021] [Indexed: 11/27/2022]
Abstract
Human embryonic stem cells (hESCs) can be self-propagated indefinitely in culture while holding the capacity to generate almost all cell types. Although this powerful differentiation ability of hESCs has become a potential source of cell replacement therapies, application of stem cells in clinical practice relies heavily on the exquisite control of their developmental fate. In general, an essential first step in differentiation is to exit the pluripotent state, which is precariously balanced and depends on a variety of factors, mainly centering on the core transcriptional mechanism. To date, much evidence has indicated that transcription factors such as Sox2, Oct4, and Nanog control the self-renewal and pluripotency of hESCs. Their expression displays a restricted spatial-temporal pattern and their small changes in level can significantly affect directed differentiation and the cell type derived. So far, few assays have been developed to monitor this process. Herein, we provided a mass spectrometry (MS)-based approach for simultaneous and quantitative monitoring of these transcription factors, in an attempt to provide insight into their contributions in hESC differentiation.
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Bohn MK, Adeli K. Application of the TML method to big data analytics and reference interval harmonization. J LAB MED 2021. [DOI: 10.1515/labmed-2020-0133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Abstract
Significant variation in reported reference intervals across healthcare centers and networks for many well-standardized laboratory tests continues to exist, negatively impacting patient outcomes by increasing the risk of inappropriate and inconsistent test result interpretation. Reference interval harmonization has been limited by challenges associated with direct reference interval establishment as well as hesitancies to apply currently available indirect methodologies. The Truncated Maximum Likelihood (TML) method for indirect reference interval establishment developed by the German Society of Clinical Chemistry and Laboratory Medicine (DGKL) presents unique clinical and statistical advantages compared to traditional indirect methods (Hoffmann and Bhattacharya), increasing the feasibility of developing indirect reference intervals that are comparable to those determined using a direct a priori approach based on healthy reference populations. Here, we review the application of indirect methods, particularly the TML method, to reference interval harmonization and discuss their associated advantages and disadvantages. We also describe the CSCC Reference Interval Harmonization Working Group’s experience with the application of the TML method in harmonization of adult reference intervals in Canada.
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Affiliation(s)
- Mary Kathryn Bohn
- Molecular Medicine and Clinical Biochemistry , The Hospital for Sick Children, University of Toronto , Toronto , ON , Canada
| | - Khosrow Adeli
- Molecular Medicine and Clinical Biochemistry , The Hospital for Sick Children, University of Toronto , Toronto , ON , Canada
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5
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Odeniyi I, Odife U, Fasanmade O, Ohwovoriole A. Surrogate markers and predictors of insulin resistance in Nigeria patients with Type 2 diabetes mellitus: A cross sectional study. JOURNAL OF CLINICAL SCIENCES 2021. [DOI: 10.4103/jcls.jcls_46_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Clinical Studies of Ci-5, Sol-gel Encapsulated Multiplex Antibody Microarray for Quantitative Fluorometric Detection of Simultaneous Five Different Tumor Antigens. BIOCHIP JOURNAL 2019. [DOI: 10.1007/s13206-019-3409-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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7
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Hendrix M, Bons J, van Haren A, van Kuijk S, van Doorn W, Kimenai DM, Bekers O, Spaanderman M, Al-Nasiry S. Role of sFlt-1 and PlGF in the screening of small-for-gestational age neonates during pregnancy: A systematic review. Ann Clin Biochem 2019; 57:44-58. [PMID: 31762291 DOI: 10.1177/0004563219882042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background Fetal growth restriction, i.e. the restriction of genetically predetermined growth potential due to placental dysfunction, is a major cause of neonatal morbidity and mortality. The consequences of inadequate fetal growth can be life-long, but the risks can be reduced substantially if the condition is identified prenatally. Currently, screening strategies are based on ultrasound detection of a small-for-gestational age fetus and do not take into account the underlying vascular pathology in the placenta. Measurement of maternal circulating angiogenic biomarkers placental growth factor, sFlt-1 (soluble FMS-like tyrosine kinase-1) are increasingly used in studies on fetal growth restriction as they reflect the pathophysiological process in the placenta. However, interpretation of the role of angiogenic biomarkers in prediction of fetal growth restriction is hampered by the varying design, population, timing, assay technique and cut-off values used in these studies. Methods We conducted a systematic-review in PubMed (MEDLINE), EMBASE (Ovid) and Cochrane to explore the predictive performance of maternal concentrations of placental growth factor, sFlt-1 and their ratio for fetal growth restriction and small-for-gestational age, at different gestational ages, and describe the longitudinal changes in biomarker concentrations and optimal discriminatory cut-off values. Results We included 26 studies with 2514 cases with small-for-gestational age, 27 cases of fetal growth restriction, 582 cases mixed small-for-gestational age/fetal growth restriction and 29,374 reference. The largest mean differences for the two biomarkers and their ratio were found after 26 weeks of gestational age and not in the first trimester. The ROC-AUC varied between 0.60 and 0.89 with sensitivity and specificity matching the different cut-off values or a preset false-positive rate of 10%. Conclusions Most of the studies did not make a distinction between small-for-gestational age and fetal growth restriction, and therefore the small-for-gestational age group consists of fetuses with growth restriction and fetuses that are constitutionally normal. The biomarkers can be a valuable screening tool for small-for-gestational age pregnancies, but unfortunately, there is not yet a clear cut-off value to use for screening. More research is needed to see if these biomarkers are sufficiently able to differentiate growth restriction on their own and how these biomarkers in combination with other relevant clinical and ultrasound parameters can be used in clinical routine diagnostics.
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Affiliation(s)
- Mle Hendrix
- Department of Obstetrics & Gynecology, GROW School of Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC), Maastricht, The Netherlands
| | - Jap Bons
- Central Diagnostic Laboratory, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - A van Haren
- Department of Obstetrics & Gynecology, GROW School of Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC), Maastricht, The Netherlands
| | - Smj van Kuijk
- Department of Clinical Epidemiology and Medical Technology Assessment (KEMTA), University Medical Centre (MUMC), Maastricht, The Netherlands
| | - Wptm van Doorn
- Central Diagnostic Laboratory, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - D M Kimenai
- Central Diagnostic Laboratory, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - O Bekers
- Central Diagnostic Laboratory, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Mea Spaanderman
- Department of Obstetrics & Gynecology, GROW School of Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC), Maastricht, The Netherlands
| | - S Al-Nasiry
- Department of Obstetrics & Gynecology, GROW School of Oncology and Developmental Biology, Maastricht University Medical Centre (MUMC), Maastricht, The Netherlands
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Bohn MK, Higgins V, Asgari S, Leung F, Hoffman B, Macri J, Adeli K. Paediatric reference intervals for 17 Roche cobas 8000 e602 immunoassays in the CALIPER cohort of healthy children and adolescents. ACTA ACUST UNITED AC 2019; 57:1968-1979. [DOI: 10.1515/cclm-2019-0707] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 07/18/2019] [Indexed: 11/15/2022]
Abstract
Abstract
Background
The diagnostic utility of laboratory tests in paediatric medicine relies heavily on the availability of appropriate reference intervals (RIs). The Canadian Laboratory Initiative on Paediatric Reference Intervals (CALIPER) has established a comprehensive database of covariate-stratified RIs for many paediatric laboratory tests using a large, healthy reference population. Several automated analysers in widespread use in clinical laboratories have already been studied. Here, we extend the testing to Roche immunoassays and report, for the first time, comprehensive paediatric RIs for 17 endocrine and special chemistry markers.
Methods
A total of 741 healthy children and adolescents (1 day to <19 years) were recruited and serum samples were analysed for 17 immunoassays on the Roche cobas 8000 e602 Immunoassay Analyzer. Age and sex-specific RIs were established and corresponding 90% confidence intervals (CIs) were calculated in accordance with Clinical and Laboratory Standards Institute guidelines.
Results
Reference values for all analytes measured required age partitioning, particularly during early life and throughout adolescence. Of the 17 analytes measured, eight required sex partitioning, including ferritin, thyroid stimulating hormone (TSH), total triiodothyronine (TT3) and all fertility/sex hormones, except prolactin.
Conclusions
This is the first study to determine accurate paediatric RIs for Roche immunoassays. RIs were generally similar to those previously published by CALIPER on other analytical platforms, highlighting the reproducibility of age- and sex-specific trends in reference values observed across the paediatric age range. The RIs established in this study will improve the accuracy of test result interpretation and clinical decision-making in clinical laboratories utilising Roche immunoassays.
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Affiliation(s)
- Mary Kathryn Bohn
- CALIPER Program, Clinical Biochemistry, Pediatric Laboratory Medicine , The Hospital for Sick Children , Toronto, ON , Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine , University of Toronto , Toronto , Canada
| | - Victoria Higgins
- CALIPER Program, Clinical Biochemistry, Pediatric Laboratory Medicine , The Hospital for Sick Children , Toronto, ON , Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine , University of Toronto , Toronto , Canada
| | - Shervin Asgari
- CALIPER Program, Clinical Biochemistry, Pediatric Laboratory Medicine , The Hospital for Sick Children , Toronto, ON , Canada
| | - Felix Leung
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine , University of Toronto , Toronto , Canada
- Department of Pathology and Laboratory Medicine , Mount Sinai Hospital , Toronto, ON , Canada
| | - Barry Hoffman
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine , University of Toronto , Toronto , Canada
- Department of Pathology and Laboratory Medicine , Mount Sinai Hospital , Toronto, ON , Canada
| | - Joseph Macri
- Department of Clinical Pathology , McMaster University , Hamilton, ON , Canada
| | - Khosrow Adeli
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine , University of Toronto , Toronto , Canada
- CALIPER Program, Clinical Biochemistry , Pediatric Laboratory Medicine , The Hospital for Sick Children , 555 University Avenue , Toronto , ON M5G 1X8, Canada
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9
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Brindle E, Lillis L, Barney R, Hess SY, Wessells KR, Ouédraogo CT, Stinca S, Kalnoky M, Peck R, Tyler A, Lyman C, Boyle DS. Simultaneous assessment of iodine, iron, vitamin A, malarial antigenemia, and inflammation status biomarkers via a multiplex immunoassay method on a population of pregnant women from Niger. PLoS One 2017; 12:e0185868. [PMID: 28982133 PMCID: PMC5628875 DOI: 10.1371/journal.pone.0185868] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/20/2017] [Indexed: 11/24/2022] Open
Abstract
Deficiencies of vitamin A, iron, and iodine are major public health concerns in many low- and middle-income countries, but information on their status in populations is often lacking due to high costs and logistical challenges associated with assessing micronutrient status. Accurate, user-friendly, and low-cost analytical tools are needed to allow large-scale population surveys on micronutrient status. We present the expansion of a 7-plex protein microarray tool for the simultaneous measurement of up to seven biomarkers with relevance to the assessment of the key micronutrients iron, iodine, and vitamin A, and inflammation and malaria biomarkers: α-1-acid glycoprotein, C-reactive protein, ferritin, retinol binding protein 4, soluble transferrin receptor, thyroglobulin, and histidine-rich protein II. Assay performance was assessed using international reference standards and then verified by comparing the multiplexed and conventional immunoassay results on a training panel of plasma samples collected from US adults. These data were used to assign nominal concentrations to the calibrators of the assay to further improve performance which was then assessed by interrogating plasma samples from a cohort of pregnant women from Niger. The correlation between assays for each biomarker measured from this cohort was typically good, with the exception of thyroglobulin, and the sensitivity ranged from 74% to 93%, and specificity from 81% to 98%. The 7-Plex micronutrient assay has the potential for use as an affordable tool for population surveillance of vitamin A, iron, and iodine deficiencies as well as falciparum malarial parasitemia infectivity and inflammation. The assay is easy-to-use, requires minimal sample volume, and is scalable, rapid, and accurate—needing only a low-cost reader and basic equipment present in most reference laboratory settings and so may be employed by low and middle income countries for micronutrient surveillance to inform on status in key populations. Micronutrient deficiencies including iron, iodine, and vitamin A affect a significant portion of the world’s population. Efforts to assess the prevalence of these deficiencies in vulnerable populations are challenging, partly due to measurement tools that are inadequate for assessing multiple micronutrients in large-scale population surveys. We have developed a 7-plex immunoassay for the simultaneous measurement of seven biomarkers relevant to assessing iodine, iron, and vitamin A status, inflammation and Plasmodium falciparum parasitemia by measuring levels of thyroglobulin, ferritin, soluble transferrin receptor, retinol binding protein 4, α-1-acid glycoprotein, C-reactive protein, and histidine-rich protein II. This 7-plex immunoassay technique has potential as a rapid and effective tool for use in large-scale surveys and assessments of nutrition intervention programs in low- and middle-income countries.
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Affiliation(s)
- Eleanor Brindle
- Center for Studies in Demography and Ecology, University of Washington, Seattle, WA, United States of America
| | | | | | - Sonja Y. Hess
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, United States of America
| | - K. Ryan Wessells
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, United States of America
| | - Césaire T. Ouédraogo
- Program in International and Community Nutrition, Department of Nutrition, University of California, Davis, CA, United States of America
- Helen Keller International, Niamey, Niger
| | - Sara Stinca
- Laboratory of Human Nutrition, Swiss Federal Institute of Technology, Zurich, Switzerland
| | | | - Roger Peck
- PATH, Seattle, WA, United States of America
| | - Abby Tyler
- Quansys Biosciences, Logan, Utah, United States of America
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Higgins V, Fung AW, Chan MK, Macri J, Adeli K. Pediatric reference intervals for 29 Ortho VITROS 5600 immunoassays using the CALIPER cohort of healthy children and adolescents. ACTA ACUST UNITED AC 2017; 56:327-340. [DOI: 10.1515/cclm-2017-0349] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/06/2017] [Indexed: 11/15/2022]
Abstract
Abstract
Background:
Accurate reference intervals (RIs) based on a healthy pediatric population are essential for pediatric test result interpretation. The CALIPER project has recruited a large healthy cohort and completed a series of a priori studies to address gaps in pediatric RIs. As immunoassays from different manufacturers for endocrine and special chemistry markers are not standardized and show marked intermethod differences, direct RI studies are needed for each major analytical platform. Here, we report age- and sex-specific pediatric RIs for 29 immunoassays on the Ortho Clinical Diagnostics (Ortho) VITROS® 5600 analyzer.
Methods:
Health information and blood samples were collected from healthy pediatric subjects. Using the Ortho VITROS 5600 Integrated System MicroWell Technology, 29 biomarkers were measured. Analyte concentrations were partitioned by age and sex according to the Harris and Boyd method. After removing outliers, age- and sex-specific RIs and corresponding 90% confidence intervals were calculated according to CLSI guidelines.
Results:
All analytes required age partitioning except β-human chorionic gonadotropin (β-hCG), cancer antigen 15-3 (CA15-3), rubella immunoglobulin G (rubella IgG), and vitamin D. Several analytes including estradiol, progesterone, testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), free triiodothyronine (FT3), total triiodothyronine (TT3), total thyroxine (TT4), thyroid uptake, ferritin, intact parathyroid hormone (iPTH), total prostate-specific antigen (tPSA), free prostate-specific antigen (fPSA), cancer antigen 125 (CA125), creatine kinase MB (CK-MB), and myoglobin showed sex differences, observed mostly with the onset of puberty.
Conclusions:
Complex reference value trends were observed across the pediatric age range for several biomarkers examined on Ortho VITROS immunoassays. The availability of VITROS immunoassay RIs will enable accurate laboratory test interpretation and diagnosis for the pediatric population. As recommended by the CLSI EP28-A3c guidelines, implementation of these RIs should be validated for each laboratory’s local pediatric population.
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Affiliation(s)
- Victoria Higgins
- CALIPER Program , Pediatric Laboratory Medicine , The Hospital for Sick Children , Toronto , ON, Canada
- Department of Laboratory Medicine and Pathobiology , University of Toronto , Toronto, ON , Canada
| | - Angela W.S. Fung
- Department of Laboratory Medicine and Pathobiology , University of Toronto , Toronto, ON , Canada
| | - Man Khun Chan
- CALIPER Program , Pediatric Laboratory Medicine , The Hospital for Sick Children , Toronto , ON, Canada
| | - Joseph Macri
- Hamilton General Hospital , McMaster University , Hamilton, ON , Canada
| | - Khosrow Adeli
- CALIPER Program , Pediatric Laboratory Medicine , The Hospital for Sick Children , Toronto , ON, Canada
- Clinical Biochemistry, DPLM, The Hospital for Sick Children , 555 University Avenue , Toronto, ON M5G 1X8 , Canada
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Bugajska J, Berska J, Mamica K, Wachacka K, Sztefko K. Which of low-density lipoprotein cholesterol estimates can be used in children with type 1 diabetes? Diagnosis (Berl) 2017. [PMID: 29536909 DOI: 10.1515/dx-2016-0034] [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: 01/19/2023]
Abstract
BACKGROUND One of the strongest risk factors of cardiovascular disease is a high concentration of low-density lipoprotein cholesterol (LDL-C); thus, the accurate measurement of LDL-C concentration in children is important. The aim of this study was to compare the concentration of LDL-C measured by direct method and the LDL-C concentration estimated by different formulas with the modified β-quantification method in children with type 1 diabetes. METHODS Thirty-one serum samples received from diabetic children (15/18; M/F) and 26 serum samples taken from nondiabetic children (18/14; M/F) were used in the study. LDL-C concentrations were determined by direct enzymatic method (LDL-CD) and the modified β-quantification method (LDL-CmBQ). The concentration of LDL-C was also calculated by different formulas. RESULTS The results of LDL-CmBQ and LDL-CD correlated. However, the correlation coefficient obtain in the nondiabetic samples was much higher (r=0.927; p<0.001) than the correlation coefficient for LDL-CmBQ and LDL-CD concentration obtained in the diabetic samples (r=0.691; p<0.001). Additionally, the coefficients of correlation between the LDL-CmBQ concentration and the LDL-C concentrations calculated by different formulas were lower in diabetic (range: 0.514-0.693) than in nondiabetic samples (range: 0.834-0.937). Bland-Altman plots showed much higher confidence intervals for 95% limits of agreement for the differences between LDL-CmBQ and LDL-CD as well as for the differences between LDL-CmBQ and LDL-C estimated by different formulas for samples from the diabetic samples compared with nondiabetic samples. CONCLUSIONS The limitations of methods measurement and of each of the formulas should be taken into account when a medical decision to lower LDL-C is made in the treatment of diabetic children.
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Affiliation(s)
- Jolanta Bugajska
- 1Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland
| | - Joanna Berska
- 1Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland
| | - Katarzyna Mamica
- 1Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland
| | - Karolina Wachacka
- 1Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland
| | - Krystyna Sztefko
- 1Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland
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Lee S, Srinivasan B, Vemulapati S, Mehta S, Erickson D. Personalized nutrition diagnostics at the point-of-need. LAB ON A CHIP 2016; 16:2408-2417. [PMID: 27272753 DOI: 10.1039/c6lc00393a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Micronutrient deficiency is widespread and negatively impacts morbidity, mortality, and quality of life globally. On-going advancements in nutritional biomarker discovery are enabling objective and accurate assessment of an individual's micronutrient and broader nutritional status. The vast majority of such assessment however still needs to be conducted in traditional centralized laboratory facilities which are not readily accessible in terms of cost and time in both the developed and developing countries. Lab-on-a-chip (LOC) technologies are enabling an increasing number of biochemical reactions at the point-of-need (PON) settings, and can significantly improve the current predicament in nutrition diagnostics by allowing rapid evaluation of one's nutritional status and providing an easy feedback mechanism for tracking changes in diet or supplementation. We believe that nutrition diagnostics represents a particularly appealing opportunity over other PON applications for two reasons: (1) healthy ranges for many micronutrients are well defined which allows for an unbiased diagnosis, and (2) many deficiencies can be reversed through changes in diet or supplementation before they become severe. In this paper, we provide background on nutritional biomarkers used in nutrition diagnostics and review the emerging technologies that exploit them at the point-of-need.
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Affiliation(s)
- Seoho Lee
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA.
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13
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Ndlandla FL, Ejoh V, Stoltz AC, Naicker B, Cromarty AD, van Wyngaardt S, Khati M, Rotherham LS, Lemmer Y, Niebuhr J, Baumeister CR, Al Dulayymi JR, Swai H, Baird MS, Verschoor JA. Standardization of natural mycolic acid antigen composition and production for use in biomarker antibody detection to diagnose active tuberculosis. J Immunol Methods 2016; 435:50-9. [PMID: 27247168 DOI: 10.1016/j.jim.2016.05.010] [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] [Received: 02/25/2016] [Revised: 04/21/2016] [Accepted: 05/24/2016] [Indexed: 10/21/2022]
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is characterized by the abundance of species specific, antigenic cell wall lipids called mycolic acids. These wax-like molecules all share an identical, amphiphilic mycolic motif, but have different functional groups in a long hydrophobic hydrocarbon mero-chain that divide them into three main classes: alpha-, keto- and methoxy-mycolic acids. Whereas alpha-mycolic acids constitutively maintain an abundance of around 50%, the ratio of methoxy- to keto-mycolic acid types may vary depending on, among other things, the growth stage of M. tuberculosis. In human patients, antibodies to mycolic acids have shown potential as diagnostic serum biomarkers for active TB. Variations in mycolic acid composition affect the antigenic properties and can potentially compromise the precision of detection of anti-mycolic acids antibodies in patient sera to natural mixtures. We demonstrate this here with combinations of synthetic mycolic acid antigens, tested against TB patient and control sera. Combinations of methoxy- and α-mycolic acids are more antigenic than combinations of keto- and α-mycolic acids, showing the former to give a more sensitive test for TB biomarker antibodies. Natural mixtures of mycolic acids isolated from mature cultures of M. tuberculosis H37Rv give the same sensitivity as that with synthetic methoxy- and α-mycolic acids in combination, in a surface plasmon resonance inhibition biosensor test. To ensure that the antigenic activity of isolates of natural mycolic acids is reproducible, we cultured M. tuberculosis H37Rv on Middlebrook 7H10 solid agar plates to stationary growth phase in a standardized, optimal way. The proportions of mycolic acid classes in various batches of the isolates prepared from these cultures were compared to a commercially available natural mycolic acid isolate. LC-MS/MS and NMR data for quantitation of mycolic acids class compositions show that the variation in batches is small, suggesting that the quality of the results for anti-mycolic acid antibody detection in the TB patients should not be affected by different batches of natural mycolic acid antigens if prepared in a standard way.
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Affiliation(s)
- F L Ndlandla
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa; Department of Biochemistry, University of Pretoria, South Africa
| | - V Ejoh
- Department of Biochemistry, University of Pretoria, South Africa
| | - A C Stoltz
- Division of Infectious Diseases, Faculty of Health Sciences, University of Pretoria, South Africa
| | - B Naicker
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa; Department of Pharmacology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - A D Cromarty
- Department of Pharmacology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - S van Wyngaardt
- Department of Biochemistry, University of Pretoria, South Africa
| | - M Khati
- Biosciences, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - L S Rotherham
- Biosciences, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - Y Lemmer
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - J Niebuhr
- Department of Biochemistry, University of Pretoria, South Africa
| | - C R Baumeister
- Department of Biochemistry, University of Pretoria, South Africa
| | | | - H Swai
- Polymers and Composites, Council for Scientific and Industrial Research, Pretoria, South Africa
| | - M S Baird
- School of Chemistry, Bangor University, Wales, UK
| | - J A Verschoor
- Department of Biochemistry, University of Pretoria, South Africa
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Wilgen U, Pretorius CJ, Gous RS, Martin C, Hale VJ, Ungerer JP. Hook effect in Abbott i-STAT β-human chorionic gonadotropin (β-hCG) point of care assay. Clin Biochem 2014; 47:1320-2. [DOI: 10.1016/j.clinbiochem.2014.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 04/30/2014] [Accepted: 05/05/2014] [Indexed: 11/17/2022]
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15
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Affiliation(s)
- Mitchell G Scott
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, and
| | - Daniel W Coyne
- Renal Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO
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Abstract
Standardization of hormone determinations is important because it simplifies interpretation of results and facilitates the use of common reference values for different assays. Progress in standardization has been achieved through the introduction of more homogeneous hormone standards for peptide and protein hormones. However, many automated methods for determinations of steroid hormones do not provide satisfactory result. Isotope dilution-mass spectrometry (ID-MS) has been used to establish reference methods for steroid hormone determinations and is now increasingly used for routine determinations of steroids and other low molecular weight compounds. Reference methods for protein hormones based on MS are being developed and these promise to improve standardization.
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Affiliation(s)
- Ulf-Håkan Stenman
- Department of Clinical Chemistry, Biomedicum, Helsinki University, PB 63, FIN-00014 Helsinki, Finland.
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Riffle BW, Henderson WM, Laws SC. Measurement of steroids in rats after exposure to an endocrine disruptor: mass spectrometry and radioimmunoassay demonstrate similar results. J Pharmacol Toxicol Methods 2013; 68:314-22. [PMID: 23871967 DOI: 10.1016/j.vascn.2013.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Commercially available radioimmunoassays (RIAs) are frequently used to evaluate the effects of endocrine disrupting chemicals (EDCs) on steroidogenesis in rats. Currently there are limited data comparing steroid concentrations in rats as measured by RIAs to those obtained using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). This study evaluates the concordance of serum and urine steroid concentrations as quantified by select RIA kits and LC-MS/MS following exposure to an EDC, atrazine (ATR). METHODS Adult male rats were orally dosed with ATR (200 mg/kg/day) or methylcellulose (1%, vehicle control) for 5 days. Serum was collected and separated into aliquots for analysis. Serum was assayed by RIA for androstenedione (ANDRO), corticosterone (CORT), estradiol (E2), estrone (E1), progesterone (P4), and testosterone (T). Serum was extracted prior to LC-MS/MS analysis with positive electrospray ionization in multiple-reaction monitoring mode for ANDRO, CORT, P4, and T. E1 and E2 concentrations were quantified similarly by LC-MS/MS, following derivatization with dansyl chloride. To compare CORT values from urine, pregnant adult rats were orally dosed with either ATR (100 mg/kg/day) or methylcellulose for 5 days (i.e., gestational days 14-18). Urine samples were collected daily and assayed for CORT by RIA and LC-MS/MS as described above. RESULTS Data analyses demonstrated significant agreement between the two detection methods as assessed by Pearson product-moment correlation coefficient, Bland-Altman analysis, and the interclass correlation coefficient. No statistically significant differences were observed between RIA and LC-MS/MS means for any of the steroids assayed. DISCUSSION These findings indicate a significant correlation between the measurement of steroids within rat serum and urine using RIA kits and LC-MS/MS. Differences in the absolute measurements existed, but these were not statistically significant. These findings indicate that steroids may be reliably measured in rat biological media using RIAs or LC-MS/MS.
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Affiliation(s)
- Brandy W Riffle
- Oak Ridge Institute for Science and Education (ORISE), Research Participation Program, Oak Ridge, TN 37831, United States; Endocrine Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory (NHEERL), Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, NC 27711, United States
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Agin A, Charrie A, Chikh K, Tabarin A, Vezzosi D. Fast test: Clinical practice and interpretation. ANNALES D'ENDOCRINOLOGIE 2013; 74:174-84. [DOI: 10.1016/j.ando.2013.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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20
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The rapidly evolving field of biomarkers of cardiac function and injury in dogs: Challenges and next steps. Vet J 2012; 191:13-4. [DOI: 10.1016/j.tvjl.2011.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 05/11/2011] [Indexed: 11/19/2022]
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21
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Gregor CR, Cerasoli E, Schouten J, Ravi J, Slootstra J, Horgan A, Martyna GJ, Ryadnov MG, Davis P, Crain J. Antibody recognition of a human chorionic gonadotropin epitope (hCGbeta66-80) depends on local structure retained in the free peptide. J Biol Chem 2011; 286:25016-26. [PMID: 21592960 DOI: 10.1074/jbc.m111.246637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human chorionic gonadotropin (hCG) is an important biomarker in pregnancy and oncology, where it is routinely detected and quantified by specific immunoassays. Intelligent epitope selection is essential to achieving the required assay performance. We present binding affinity measurements demonstrating that a typical β3-loop-specific monoclonal antibody (8G5) is highly selective in competitive immunoassays and distinguishes between hCGβ(66-80) and the closely related luteinizing hormone (LH) fragment LHβ(86-100), which differ only by a single amino acid residue. A combination of optical spectroscopic measurements and atomistic computer simulations on these free peptides reveals differences in turn type stabilized by specific hydrogen bonding motifs. We propose that these structural differences are the basis for the observed selectivity in the full protein.
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Affiliation(s)
- Craig R Gregor
- School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, Scotland, United Kingdom
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Tate JR, Bunk DM, Christenson RH, Katrukha A, Noble JE, Porter RA, Schimmel H, Wang L, Panteghini M. Standardisation of cardiac troponin I measurement: past and present. Pathology 2010; 42:402-8. [DOI: 10.3109/00313025.2010.495246] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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23
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Ceglarek U, Werner M, Kortz L, Körner A, Kiess W, Thiery J, Kratzsch J. Preclinical challenges in steroid analysis of human samples. J Steroid Biochem Mol Biol 2010; 121:505-12. [PMID: 20302937 DOI: 10.1016/j.jsbmb.2010.03.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 03/02/2010] [Accepted: 03/08/2010] [Indexed: 11/25/2022]
Abstract
Preclinical challenges in the analysis of steroid hormones are primarily determined by biological factors involved in the physiology and pathophysiology of hormone secretion. Major biologically influencing factors like age, sex, pubertal stage, pregnancy, phase of the menstruation, and diurnal rhythm have to be considered in the definition of reference ranges for steroids and their clinical interpretation. Hitherto, in clinical routine laboratories steroids were mainly determined by direct immunoassays applied on automated platforms, which are simple, rapid and cheap if a high number of samples are measured. However, technical factors like cross-reactivity of related steroid metabolites or limited analytical ranges have to be taken in account and may impair accuracy and precision of these direct methods. The actual development of mass spectrometry based analytical platforms for the determination of single steroid or steroid patterns seems to be an alternative analytical approach combining multi-parametric analysis, high sensitivity and specificity as well simple sample pre-treatment, robustness and low running costs for steroid analysis. This short review will give an overview about biological influencing factors and technical disturbing factors of routinely used immunoassay for the analysis of steroids. The application of LC-MS/MS as an alternative routine high-throughput platform for steroid analysis and its perspective role in the standardization and harmonisation of steroid measurements in clinical routine application will be discussed.
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Affiliation(s)
- Uta Ceglarek
- Institute for Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, Paul List-Str.13-15, Germany
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24
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Thorpe SJ. The development and role of international biological reference materials in the diagnosis of anaemia. Biologicals 2010; 38:449-58. [DOI: 10.1016/j.biologicals.2010.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Accepted: 02/05/2010] [Indexed: 10/19/2022] Open
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Bidlingmaier M, Freda PU. Measurement of human growth hormone by immunoassays: current status, unsolved problems and clinical consequences. Growth Horm IGF Res 2010; 20:19-25. [PMID: 19818659 PMCID: PMC7748084 DOI: 10.1016/j.ghir.2009.09.005] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 09/17/2009] [Indexed: 01/28/2023]
Abstract
Measuring the concentration of growth hormone (GH) in blood samples taken during dynamic tests represents the basis for diagnosis of growth hormone related disorders, namely growth hormone deficiency and growth hormone excess. Today, a wide spectrum of immunoassays are in use, enabling rapid and sensitive determination of growth hormone concentrations in routine diagnostics. From a clinical point of view several difficulties exist with the use and interpretation of GH assay results in the assessment of GH related disorders: Many physiological factors such as fat mass, age and gender influence the outcome of dynamic tests, overall leading to significant inter-individual differences in GH responses. However, in addition to the physiological variability, considerable variability exists in GH assay results obtained by different immunoassays. Unfortunately, all the new technical advances in the field of GH measurement techniques have not reduced this methodological variability. To a large extent, the actual values reported for the GH concentration in a sample depend on the method used by the respective laboratory. Obviously, such discrepancies limit the applicability of consensus guidelines on diagnosis and treatment in clinical practice. This review summarizes current practices for GH measurement with respect to the methods used, their limitations and the clinical consequences of the existing heterogeneity in GH immunoassay results.
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Affiliation(s)
- Martin Bidlingmaier
- Endocrine Research Laboratories, Medizinische Klinik - Innenstadt, Ludwig-Maximilians University, Munich, Germany.
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26
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Thorpe SJ, Heath A, Sharp G, Cook J, Ellis R, Worwood M. A WHO Reference Reagent for the Serum Transferrin Receptor (sTfR): international collaborative study to evaluate a recombinant soluble transferrin receptor preparation. Clin Chem Lab Med 2010; 48:815-20. [DOI: 10.1515/cclm.2010.167] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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28
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Binkley N, Krueger D, Lensmeyer G. 25-hydroxyvitamin D measurement, 2009: a review for clinicians. J Clin Densitom 2009; 12:417-27. [PMID: 19734080 DOI: 10.1016/j.jocd.2009.06.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 06/05/2009] [Accepted: 06/05/2009] [Indexed: 11/23/2022]
Abstract
As clinicians are more widely appreciating the endemic nature of low vitamin D status, measurement of serum 25-hydroxyvitamin D (25(OH)D), the accepted measure of vitamin D status, has increased. Challenges to 25(OH)D measurement include the presence of 2 forms of vitamin D-ergocalciferol and cholecalciferol (vitamin D(2) and vitamin D(3), respectively)- and the hydrophobic nature of vitamin D. The current state of 25(OH)D measurement is reviewed; modest differences between methodologies persist and confound the application of a single cut point (e.g., 30 ng/mL/75 nmol/L) for the diagnosis of low vitamin D status. The absence of standard calibrators contributes to between-laboratory differences in 25(OH)D measurement. Until there is improved assay standardization and subsequent evidence-based consensus, it seems premature to recommend widespread screening 25(OH)D measurement. Selectively obtaining 25(OH)D measurement in individuals at clinical risk for vitamin D deficiency and/or those most likely to promptly experience benefits from supplementation seems appropriate.
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Affiliation(s)
- Neil Binkley
- Osteoporosis Clinical Center and Research Program, University of Wisconsin-Madison, Madison, WI 53705, USA.
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29
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Jakobsen J, Bysted A, Andersen R, Bennett T, Brot C, Bügel S, Cashman KD, Denk E, Harrington M, Teucher B, Walczyk T, Ovesen L. Vitamin D status assessed by a validated HPLC method: within and between variation in subjects supplemented with vitamin D3. Scandinavian Journal of Clinical and Laboratory Investigation 2009; 69:190-7. [DOI: 10.1080/00365510802471570] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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30
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Dullnig V, Weiss R, Amon S, Rizzi A, Stutz H. Confirmation of immuno-reactivity of the recombinant major birch pollen allergen Bet v 1a by affinity-CIEF. Electrophoresis 2009; 30:2337-46. [DOI: 10.1002/elps.200800749] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
Dr Ferdousi Chowdhury is a clinical immunology research fellow and joined the Southampton Cancer Research UK clinical centre in 2004 as a Research Assistant to acquire the skills and knowledge required for the transition from basic research to regulated research. She has now become a key player at the Southampton Experimental Cancer Medicine Centre (ECMC, UK) working as the Clinical Immunology Research Fellow involved in all aspects of validation of both cellular (flow cytometry, ELISpot and tetramer) and humoral analysis studies (ELISA including pharmacokinetic and human anti-chimeric antibody assays, Luminex and MSD multiplex platforms). Ferdousi Chowdhury has presented validation work on multiplex technology at both national and international meetings. At Southampton ECMC, we continue to be challenged by the speed of technological advancement and strive to accommodate these within the ever-evolving stringent regulatory framework for early phase clinical trials. The current decade has seen an evolution in biomarker research, with a breakthrough from traditional single analyte studies to simultaneous multiple analyte technologies, aided by the progressive development of research tools and the discovery of many novel biomarkers. It is foreseeable that the application of such technologies will have an integral role in clinical studies for establishing biomarker profiles of disease status and prognosis. However, the transfer of such complex procedures to a regulated environment presents many obstacles. Here, we discuss some of these applied technologies and the validation approaches we have taken as an academic unit to prove their suitability and appropriateness for clinical application. We discuss the advantages and limitations for such end point assays in early Phase clinical trials.
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32
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Traceability as a unique tool to improve standardization in laboratory medicine. Clin Biochem 2009; 42:236-40. [DOI: 10.1016/j.clinbiochem.2008.09.098] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Accepted: 09/11/2008] [Indexed: 11/19/2022]
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33
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Pichon MF, Brun GL, Hacene K, Basuyau JP, Riedinger JM, Eche N, Fulla Y, Charlier-Bret N. Comparison of fifteen immunoassays for the measurement of serum MUC-1/CA 15-3 in breast cancer patients. Clin Chem Lab Med 2009; 47:985-92. [DOI: 10.1515/cclm.2009.213] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Chowdhury F, Williams A, Johnson P. Validation and comparison of two multiplex technologies, Luminex and Mesoscale Discovery, for human cytokine profiling. J Immunol Methods 2009; 340:55-64. [PMID: 18983846 DOI: 10.1016/j.jim.2008.10.002] [Citation(s) in RCA: 199] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 09/26/2008] [Accepted: 10/06/2008] [Indexed: 01/31/2023]
Abstract
Biomarker research has rapidly expanded over recent years aided by the progressive development of research tools, in particular the different multiplex technologies allowing simultaneous measurement of multiple analytes. It is foreseeable that such technology will have an integral role in clinical studies for establishing biomarker profiles of disease status, but validation of the tools is essential to confirm the reliability of their application. More comparable studies between multiplex platforms are required to enable users to determine which of these are best for a particular clinical study, as different platforms will have varying levels of performance for the validation parameters. Comparison of two multiplex platforms, the Luminex and the Mesoscale Discovery, has been performed to determine their performance for the validation parameters of sensitivity, precision and accuracy for the cytokines IL-2, IL-4, IL-8, IL-10, IL-12, IFNgamma and TNFalpha. When measuring high concentrations both platforms show good accuracy (within +/-25% recovery) with all cytokines except IL-12 for the MSD. At low concentrations, +/-25% recovery was seen with all cytokines except IL-2 and IL-8 for the Luminex and IL-2 and IL-12 for the MSD. Although quantitative differences are found, relative differences are comparable, and consequently both platforms have been shown to be suitable for analyzing trends in multiple cytokine profiles, with the Luminex having better precision and the Mesoscale Discovery having greater sensitivity.
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Affiliation(s)
- Ferdousi Chowdhury
- Cancer Sciences Division, CRUK Clinical Centre, Somers Cancer Research Building, University of Southampton, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, England, United Kingdom
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Enea C, Boisseau N, Diaz V, Dugué B. Biological factors and the determination of androgens in female subjects. Steroids 2008; 73:1203-16. [PMID: 18640139 DOI: 10.1016/j.steroids.2008.06.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 06/20/2008] [Accepted: 06/23/2008] [Indexed: 11/23/2022]
Abstract
The idea of the presence of androgens in females may sound peculiar as androgens generally refer to male hormones. Although produced in small amounts in women, androgens have direct and significant effects on many aspects of female physiology. Moreover, androgens are precursors to estrogens, which are the predominant female sex hormones. The measurement of androgens in blood is important in the diagnosis of both gonadal and adrenal functional disturbances, as well as monitoring subsequent treatments. The accuracy of such measurements is crucial in sports medicine and doping control. Therefore, the concentration of androgens in female subjects is frequently measured. Analysing such compounds with accuracy is especially difficult, costly and time consuming. Therefore, laboratories widely use direct radioimmunoassay kits, which are often insensitive and inaccurate. It is especially complicated to determine the level of androgens in women, as the concentration is much lower compared to the concentration found in males. Additionally, the amount of androgens in fluids tends to decrease with aging. Analyses of hormone concentrations are influenced by a myriad of factors. The factors influencing the outcome of these tests can be divided into in vivo preanalytical factors (e.g., aging, chronobiological rhythms, diet, menstrual cycle, physical exercise, etc.), in vitro preanalytical factors (e.g., specimen collection, equipment, transport, storage, etc.) and as mentioned before, analytical factors. To improve the value of these tests, the strongly influencing factors must be controlled. This can be accomplished using standardised assays and specimen collection procedures. In general, sufficient attention is not given to the preanalytical (biological) factors, especially in the measurement of androgens in females. Biological factors (non-pathological factors) that may influence the outcome of these tests in female subjects have received little attention and are the topic of the present review.
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Affiliation(s)
- C Enea
- Laboratoire des Adaptations Physiologiques aux Activités Physiques (EA3813), Université de Poitiers, and Service d'Exploration Fonctionnelle Respiratoire et Physiologie de l'Exercice, Centre Hospitalier Universitaire de Poitiers, 86000 Poitiers, France
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Panteghini M, Bunk DM, Christenson RH, Katrukha A, Porter RA, Schimmel H, Wang L, Tate JR. Standardization of troponin I measurements: an update. Clin Chem Lab Med 2008; 46:1501-6. [DOI: 10.1515/cclm.2008.291] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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37
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Wang L, Cole KD, Peterson A, He HJ, Gaigalas AK, Zong Y. Monoclonal Antibody Selection for Interleukin-4 Quantification Using Suspension Arrays and Forward-Phase Protein Microarrays. J Proteome Res 2007; 6:4720-7. [DOI: 10.1021/pr070535s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L. Wang
- Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8312
| | - K. D. Cole
- Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8312
| | - A. Peterson
- Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8312
| | - Hua-Jun He
- Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8312
| | - A. K. Gaigalas
- Biochemical Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8312
| | - Y. Zong
- Full Moon BioSystems, Inc., 754 North Pastoria Avenue, Sunnyvale, California 94085
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Gapper LW, Copestake DEJ, Otter DE, Indyk HE. Analysis of bovine immunoglobulin G in milk, colostrum and dietary supplements: a review. Anal Bioanal Chem 2007; 389:93-109. [PMID: 17579844 DOI: 10.1007/s00216-007-1391-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 05/17/2007] [Accepted: 05/24/2007] [Indexed: 10/23/2022]
Abstract
The immunoprotective properties of bovine milk immunoglobulin G (IgG) have led to a recent proliferation of nutritional products incorporating this protein. It has therefore become critical that reliable analytical techniques for the measurement of the IgG content in such products are available. This literature review surveys current methods of analysis for IgG, including separation-based or immuno-based concentration analysis. The review also discusses nutraceutical applications, regulatory issues, stability of IgG and the significance of primary reference material in IgG analysis.
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Affiliation(s)
- Leyton W Gapper
- Fonterra Research Centre, Dairy Farm Road, Private Bag 11029, Palmerston North, New Zealand
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Sapin R. Insulin immunoassays: fast approaching 50 years of existence and still calling for standardization. Clin Chem 2007; 53:810-2. [PMID: 17468407 DOI: 10.1373/clinchem.2006.084012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Methuen T, Kylänpää L, Kekäläinen O, Halonen T, Tukiainen E, Sarna S, Kemppainen E, Haapiainen R, Puolakkainen P, Salaspuro M. Disialotransferrin, determined by capillary electrophoresis, is an accurate biomarker for alcoholic cause of acute pancreatitis. Pancreas 2007; 34:405-9. [PMID: 17446838 DOI: 10.1097/mpa.0b013e318043c164] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES Serum disialotransferrin is a specific marker of heavy alcohol consumption. We tested its accuracy and probability in detecting alcoholic cause of acute pancreatitis (AP). METHODS Blood samples from 271 consecutive AP patients, admitted to the Helsinki University Central Hospital emergency unit, were analyzed. RESULTS The median (range) disialotransferrin value was significantly higher (P = 0.001) in AP patients with alcoholic (n = 172) 1.6% (0.3%-14.4) than with biliary (n = 60) 0.7% (0.3%-1.3%) or other causes (n = 39) 0.8% (0.3%-4.1%). In receiver operating curve analysis, disialotransferrin, as a single analyte, was significantly (P = 0.001-0.0001) more accurate (area under the curve [AUC], 0.88; 95% confidence interval [CI], 0.84-0.92) in detecting alcoholic AP as compared with glutamyl transferase (AUC, 0.51; 95% CI, 0.45-0.57), aspartate aminotransferase (AUC, 0.57; 95% CI, 0.51-0.63), alanine aminotransferase (AUC, 0.63; 95% CI, 0.57-0.69), erythrocyte mean cell volume (AUC, 0.72; 95% CI, 0.67-0.78), amylase (AUC, 0.74; 95% CI, 0.67-0.78), C-reactive protein (AUC, 0.65; 95% CI, 0.59-0.71), and bilirubin (AUC, 0.55; 95% CI, 0.49-0.62). At a disialotransferrin cutoff of 1.2%, giving an 8% false-positive rate, the positive likelihood ratio was 8.47. Thus, a positive disialotransferrin test result, performed within 24 hours of admission, increased the probability of alcoholic AP from pretest 64% to posttest 94%. CONCLUSIONS Disialotransferrin, determined by capillary electrophoresis, is accurate, simple, and a rapid single biomarker of the alcoholic cause of AP.
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Affiliation(s)
- Taina Methuen
- Research Unit of Substance Abuse Medicine, University of Helsinki, Helsinki, Finland
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Sturgeon CM, Ellis AR. Standardization of FSH, LH and hCG--current position and future prospects. Mol Cell Endocrinol 2007; 260-262:301-9. [PMID: 17113221 DOI: 10.1016/j.mce.2006.09.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Accepted: 02/11/2006] [Indexed: 11/29/2022]
Abstract
Gonadotropin measurements contribute significantly to patient management in both endocrinology and oncology. Differences in calibration, antibody specificities and assay design mean that gonadotropin results obtained in different methods are still not comparable. Comparing patient results obtained in different methods therefore remains problematic, whether for individual patient care, when assessing the results of multicentre clinical trials, or when formulating national and international guidelines and recommendations. Achieving improved comparability of results for these important analytes will require clear descriptive nomenclature, accurate calibration with highly purified standards, careful characterization of what gonadotropin isoforms methods are measuring, broad recommendations about the most clinically appropriate antibody combinations, and increased awareness of clinically relevant interferences and the action required to minimise their effect. Encouraging manufacturers to standardize and carefully describe the evaluation methods they use, such that data from different manufacturers can readily be compared, is also a pre-requisite for future progress.
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Affiliation(s)
- C M Sturgeon
- UK NEQAS for Peptide Hormones, Department of Clinical Biochemistry, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA, UK.
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Abstract
Measurement of circulating growth hormone (GH) concentrations is essential in diagnosis of either GH deficiency or GH excess. The invention of immunoassays for the measurement of peptide hormones was a major breakthrough, enabling the routine analysis of GH concentrations in larger series of samples. Over the last few decades, measurement technology has evolved from less sensitive, mainly radioactive assays based on polyclonal antisera to the latest generations of highly sensitive chemiluminescence methods employing monoclonal antibodies. Unfortunately, the development of newer assays did not lead to better agreement among the results obtained by different assay methods. On the contrary, the differences tended to increase when monoclonal antibody based assays became more popular. The actual value reported for the GH concentration in a specific patient's sample still mainly depends on the method used by the respective laboratory, limiting the applicability of international consensus guidelines in clinical practice. The heterogeneity of the analyte itself, the availability of different reference preparations for calibration and the interference from matrix components such as GH binding protein are among the reasons why standardizing GH assays is difficult. An additional challenge arose from the availability of a GH receptor antagonist for the treatment of acromegaly, which is basically a mutated form of GH and therefore interferes in many GH assays. This review provides an overview on GH assays used in clinical practice, their limitations and the potential next steps towards standardization.
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Affiliation(s)
- Martin Bidlingmaier
- Endocrine Research Laboratories, Medizinische Klinik-Innenstadt, Ludwig-Maximilians University, Ziemssenstr. 1, 80336 Munich, Germany.
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Ljungdahl N, Haarhaus M, Linder C, Magnusson P. Comparison of 3 third-generation assays for bio-intact parathyroid hormone. Clin Chem 2006; 52:903-4. [PMID: 16638963 DOI: 10.1373/clinchem.2005.065821] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Donadio S, Pascual A, Dugas M, Ronin C. Standardisation des immunodosages de la TSH : production de nouveaux calibrateurs et harmonisation des tests. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.immbio.2005.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rigo RF, Alía P, Rosel P, Navarro MA. Diluent Multiassay for the MODULAR ANALYTICS E170 does not improve TSH dilutions compared to Diluent Universal. Clin Chem Lab Med 2006; 44:353-4. [PMID: 16519611 DOI: 10.1515/cclm.2006.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Thienpont LM, Van Uytfanghe K, Marriott J, Stokes P, Siekmann L, Kessler A, Bunk D, Tai S. Feasibility Study of the Use of Frozen Human Sera in Split-Sample Comparison of Immunoassays with Candidate Reference Measurement Procedures for Total Thyroxine and Total Triiodothyronine Measurements. Clin Chem 2005; 51:2303-11. [PMID: 16223886 DOI: 10.1373/clinchem.2005.058180] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Diagnostic manufacturers must ensure/document metrologically traceable assays. We report on a feasibility study of a split-sample comparison for that purpose. Processed, frozen single-donation sera, assigned target values by candidate reference measurement procedures (cRMPs), were used with immunoassays for total thyroxine (TT4) and triiodothyronine (TT3) as models.
Methods: Two serum panels were quantified for TT4 and TT3 with validated cRMPs and measured in parallel with at least 14 immunoassays. The results were interpreted in terms of traceability of calibration (trueness) and of the individual measurement result (accuracy) by linear regression analysis and graphical representation against specifications. The commutability of the sera was investigated by parallel analysis of TT4 in freshly collected but nonfiltered specimens.
Results: The TT4 (TT3) concentrations in the sera (according to the cRMPs) were 64–269 nmol/L (0.88–13.7 nmol/L). The method comparison showed that for TT4, on average, the immunoassays produced results in agreement with the cRMPs, whereas for TT3, results were typically higher. It also demonstrated a considerable between-assay divergence in traceability of calibration and accuracy. The evidence of noncommutability of the sera attributable to processing, however, indicates that the interpretation should be treated with caution.
Conclusions: Frozen sera can be used for documenting/validating traceability of total thyroid measurements. The way in which the sera are processed may jeopardize commutability, however, and therefore requires in-depth investigation.
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Affiliation(s)
- Linda M Thienpont
- Laboratory for Analytical Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Belgium.
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48
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Affiliation(s)
- Mauro Panteghini
- Cattedra di Biochimica Clinica e Biologia Molecolare Clinica, Dipartimento di Scienze Cliniche Luigi Sacco, Facoltà di Medicina e Chirurgia - Polo di Vialba, Università degli Studi di Milano, Milan, Italy.
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Panteghini M, Forest JC. Standardization in laboratory medicine: new challenges. Clin Chim Acta 2005; 355:1-12. [PMID: 15820472 DOI: 10.1016/j.cccn.2004.12.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Revised: 12/07/2004] [Accepted: 12/28/2004] [Indexed: 10/25/2022]
Abstract
The primary goal of Laboratory Medicine is to provide information that is useful to assist medical decision-making and permits optimal health care. This type of information should be independently obtained of the measurement test kits and instruments, and also of the laboratory where the procedure is carried out. It is therefore important to achieve a level of comparability of laboratory results among the many measurement procedures available so that results are harmonized and interchangeable over space and time. The standardization of measurements is therefore of high priority. In recent years, numerous efforts have been made at the international level under the auspices of the IFCC and other organizations to standardize measurement results for many important analytes, e.g. enzymes, cardiac proteins, etc. The aim of this review is to discuss some concepts related to the achievement of standardization by the implementation of a metrologically correct measurement system, providing some examples on how these concepts can be applied in Laboratory Medicine.
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Affiliation(s)
- M Panteghini
- Laboratorio Analisi Chimico Cliniche 1, Azienda Ospedaliera "Spedali Civili", 25123 Brescia, Italy.
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Wan B, Augustin R, Chan MK, Leblond J, Verjee Z, Adeli K. Analytical performance and workflow evaluation of the Roche E170 modular immunoassay analyzer in a pediatric setting. Clin Biochem 2005; 38:262-71. [PMID: 15708549 DOI: 10.1016/j.clinbiochem.2004.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 11/25/2004] [Accepted: 11/30/2004] [Indexed: 11/15/2022]
Abstract
OBJECTIVES To evaluate the analytical performance of the Roche E170 modular analytics immunoassay analyzer and assess its impact on workflow efficiency and ability to consolidate workstations in a pediatric setting. DESIGN AND METHODS Analytical performance of eleven common immunoassays was assessed. Total imprecision was determined using Roche PreciControl Universal controls, Bio-Rad Lyphochek Immuno Plus, Anemia controls, and a human serum pool. Method comparison was performed with approximately 100 patient specimens. High dose hook effect, sample carryover, and results comparison between the two measuring channels were evaluated. For the workflow study, the time required for sample and reagent handling, instrument preparation, and hands-on time were assessed. RESULTS Correlation coefficients with existing methods ranged from 0.941 to 0.999. Biases of -19% to 70% were observed. Total imprecision ranged from 1.1 to 7.6%. No sample carryovers were encountered. Results from both measuring channels were comparable. CONCLUSION E170 is suitable for use in a pediatric setting. The analytical performance is acceptable and gives equivalent results to our existing systems. The precision is comparable and acceptable. Some improvement in efficiency, workflow, cost saving, and consolidation of workstations is possible. Significant workflow improvements can only be realized when integrated with the chemistry modules.
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Affiliation(s)
- Betty Wan
- Division of Clinical Biochemistry, The Hospital for Sick Children, Department of Paediatric Laboratory Medicine, 555 University Avenue, Toronto, Canada M5G 1X8
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