Multicenter performance evaluation of a second generation cortisol assay

Abstract Background: Untreated disorders of the adrenocortical system, such as Cushing’s or Addison’s disease, can be fatal, and accurate quantification of a patient’s cortisol levels is vital for diagnosis. The objective of this study was to assess the analytical performance of a new fully-automated Elecsys® Cortisol II assay (second generation) to measure cortisol levels in serum and saliva. Methods: Four European investigational sites assessed the intermediate precision and reproducibility of the Cortisol II assay (Roche Diagnostics) under routine conditions. Method comparisons of the Cortisol II assay vs. liquid chromatography-tandem mass spectrometry (LC-MS/MS), the gold standard for cortisol measurement, were performed. Cortisol reference ranges from three US sites were determined using samples from self-reported healthy individuals. Results: The coefficients of variation (CVs) for repeatability, intermediate precision, and reproducibility for serum samples were ≤2.6%, ≤5.8%, and ≤9.5%, respectively, and for saliva were ≤4.4% and ≤10.9%, and ≤11.4%, respectively. Agreement between the Cortisol II assay and LC-MS/MS in serum samples was close, with a slope of 1.02 and an intercept of 4.473 nmol/L. Reference range samples were collected from healthy individuals (n=300) and serum morning cortisol concentrations (5–95th percentile) were 166.1–507 nmol/L and afternoon concentrations were 73.8–291 nmol/L. Morning, afternoon, and midnight saliva concentrations (95th percentile) were 20.3, 6.94, and 7.56 nmol/L, respectively. Conclusions: The Cortisol II assay had good precision over the entire measuring range and had excellent agreement with LC-MS/MS. This test was found suitable for routine diagnostic application and will be valuable for the diagnosis of adrenocortical diseases.

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SAT-166 Advantage and Trustworthy of Cortisol and Dexamethasone Evaluation in Different Biological Matrices in Patients with Adrenal Masses

Journal of the Endocrine Society ◽

10.1210/jendso/bvaa046.1680 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

Author(s):

Luana Lionetto ◽

Roberta Maggio ◽

Pina Lardo ◽

Donatella De Bernardini ◽

Fabiola Cipolla ◽

...

Keyword(s):

Salivary Cortisol ◽

Adrenal Incidentaloma ◽

Serum Cortisol ◽

Reference Ranges ◽

Serum Samples ◽

Late Night ◽

Liquid Chromatography Tandem Mass ◽

Adrenal Masses ◽

Suppression Test ◽

The Individual

Abstract Biochemical function of adrenal masses is currently based on 1mg post-overnight dexamethasone suppression test (pDST). Several approaches are recently developed, in order to reduce false positive/negative samples, only in retrospective series. They are based on the correlation of some different parameters, i.e. late-night salivary cortisol (LNSC) vs serum and salivary cortisol pDST; LNSC vs serum and salivary cortisol and serum dexamethasone pDST; LNSC and cortisone vs serum cortisol and salivary cortisol and cortisone pDST. Although these findings offer a better diagnostic performance, several conditions are still disappointed. No information is traceable about the harvest time of diurnal salivary and serum samples and no study include neither the levels of salivary nor urinary dexamethasone pDST. Aim of our study is to combine all these strategies in order to avoid the underestimated biases and obtain more precise information about the true “cortisol condition” of the patients. To reach this purpose we assess both cortisol and dexamethasone concentrations in several samples: saliva at 11PM before the drug administration, diurnal saliva and serum at 8AM and also the urine collection from 11PM to 8AM. Analytes levels are measured using a validated liquid chromatography-tandem mass spectrometry method. In this study we included 20 subjects without morphological adrenal alteration (MRI assessment), dyslipidemia, hypertension and impaired glucose tolerance (healthy controls) and 20 patients with adrenal incidentaloma showing different cortisol levels ranging from normal to ACTH-independent hypercortisolism. In both series, LNSC were similar to salivary cortisol pDST, even if they were greater in the patients with adrenal incidentalomas and subclinical cortisol secretion. Serum dexamethasone levels were in reference ranges, while salivary and urinary dexamethasone found in these matrices require additional sample numbers in order to establish appropriate cut-offs. Our preliminary results suggest that the combination of these findings could represent an improvement to assess the individual cortisol status.

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Analytical evaluation of the Dade Behring Dimension RxL automated N-Terminal proBNP (NT-proBNP) method and comparison with the Roche Elecsys 2010

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm.2005.217 ◽

2005 ◽

Vol 43 (11) ◽

Cited By ~ 28

Author(s):

Francesca Di Serio ◽

Vincenzo Ruggieri ◽

Lucia Varraso ◽

Rosalisa De Sario ◽

Angela Mastrorilli ◽

...

Keyword(s):

Detection Limit ◽

Healthy Subjects ◽

Effect Of Temperature ◽

Serum Samples ◽

Coefficients Of Variation ◽

Sample Stability ◽

The Matrix ◽

Heparin Plasma ◽

Roche Diagnostics ◽

Age And Sex

AbstractMethods to quantify B-type natriuretic peptide (BNP) and N-terminal-propeptide (NT-proBNP) in plasma or serum samples are well established. We assessed the analytical performance of the Dimension RxL NT-proBNP method (Dade-Behring). Evaluation of different sample types was carried out. Controls and heparin plasma pools were used to determine the detection limit, precision, and linearity. Sample stability and the effect of interfering substances on the NT-proBNP concentrations were evaluated. Agreement between Dimension RxL and Elecsys 2010 (Roche Diagnostics) NT-proBNP methods was assessed. The influence of age and sex on NT-proBNP concentrations was evaluated in healthy subjects. Heparin plasma should be the matrix of choice. The detection limit was 2.0ng/L. The total imprecision was 2.6–3.6% for concentrations from 231 to 9471ng/L; mean NT-proBNP concentrations of 21 and 15ng/L were associated with coefficients of variation of 9.9% and 14.7%, respectively. The method was linear up to 32,650ng/L. There was no effect of temperature, freeze-thaw cycles and interfering substances. A bias was detected when Dimension RxL and Elecsys 2010 NT-proBNP methods were compared. Age and sex were significantly and independently related to NT-proBNP concentrations. The Dimension RxL NT-proBNP method, like the Elecsys 2010, is suitable for routine use in the diagnosis of heart failure.

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A monoclonal-based IgM capture ELISA for detection of antibodies to 22 and 41 kDa membrane antigens ofToxoplasma gondii

Parasitology ◽

10.1017/s0031182000060765 ◽

1992 ◽

Vol 104 (1) ◽

pp. 25-31 ◽

Cited By ~ 2

Author(s):

J. L. K. Wee ◽

L. C. Ho ◽

E. H. Yap ◽

M. Singh

Keyword(s):

Monoclonal Antibody ◽

Rheumatoid Factor ◽

Surface Antigens ◽

Elisa Test ◽

Enzyme Linked Immunosorbent Assay ◽

Healthy Individuals ◽

Serum Samples ◽

Negative Results ◽

Coefficients Of Variation ◽

Membrane Antigens

SUMMARYA murine monoclonal antibody which reacts to 22 and 41 kDaToxoplasma gondiisurface antigens was employed in an IgM capture enzyme-linked immunosorbent assay (ELISA). A total of 125 patients' sera were tested in the monoclonal-based assay. When compared with a commercial ELISA test (Abbott Toxo-M EIA) which uses polyclonal anti-T. gondiiantibodies, good correlation (Pearsons coefficientr= 0.91) was observed. The specificity of the assay was studied by testing a panel of control sera obtained from healthy individuals and blood transfusion donors; all sera gave negative results. Serum samples positive forT. gondiiantibodies were treated with 2-mercaptoethanol (2-ME) to demonstrate the specificity of the test for IgM antibodies. Reactivity of these sera was lost after the treatment. The test is not subject to interference by rheumatoid factor as sera positive for rheumatoid factor were negative in the assay. Reproducibility was good with the coefficients of variation for within-day tests below 10% and not exceeding 18% for day-to-day tests. The monoclonal-based assay is simple to perform and appears to be a viable test for diagnosis ofT. gondiiinfection.

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Measurement of sirolimus concentrations in human blood using an automated electrochemiluminescence immunoassay (ECLIA): a multicenter evaluation

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2017-0583 ◽

2018 ◽

Vol 56 (5) ◽

pp. 764-775 ◽

Cited By ~ 3

Author(s):

Veronique Stove ◽

Pedro Alía Ramos ◽

Pierre Wallemacq ◽

Michael Vogeser ◽

Andre Schuetzenmeister ◽

...

Keyword(s):

Reference Method ◽

Therapeutic Drug ◽

Good Precision ◽

Transplant Recipients ◽

Intermediate Precision ◽

Deming Regression ◽

Limit Of Quantitation ◽

Liquid Chromatography Tandem Mass ◽

Chemiluminescent Microparticle Immunoassay ◽

Electrochemiluminescence Immunoassay

AbstractBackground:Therapeutic drug monitoring (TDM) of sirolimus is essential in transplant recipients. We evaluated the performance of a new electrochemiluminescence immunoassay (ECLIA) for measuring sirolimus concentrations in whole blood at five European laboratories.Methods:Study assessments included repeatability, intermediate precision and functional sensitivity (concentration at coefficient of variation [CV] of 20%) experiments. Method comparisons with liquid chromatography-tandem mass spectrometry (LC-MS/MS; reference method) and two immunoassays (chemiluminescent microparticle immunoassay [CMIA] and antibody-conjugated magnetic immunoassay [ACMIA]) were performed using native samples from patients with kidney transplants.Results:Imprecision testing CVs were ≤6.4% and ≤10.7% across the sirolimus concentration range for both repeatability and intermediate precision, respectively. The ECLIA showed excellent functional sensitivity: the CV did not reach 20%; the CV at the assay’s limit of quantitation (1.5 μg/L) was 7.0%. Agreement between the ECLIA and LC-MS/MS using native kidney samples was close, with weighted Deming regression analysis yielding a slope of 1.05, an intercept of 0.154 μg/L and a Pearson’s correlation coefficient (r) of 0.94, while Bland-Altman analysis showed a combined mean bias of 0.41 μg/L (±2 standard deviation [SD], −1.96 to 2.68). The ECLIA also showed good correlation with the two other immunoassays: the CMIA (slope=0.91, intercept=0.112 μg/L and r=0.89) and the ACMIA (slope=0.99, intercept=0.319 μg/L and r=0.97).Conclusions:The ECLIA showed good precision, functional sensitivity and agreement with other methods of sirolimus measurement used in clinical practice, suggesting that the assay is suitable for TDM in transplant recipients and provides an alternative to LC-MS/MS.

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Serum Total Prolactin and Monomeric Prolactin Reference Intervals Determined by Precipitation with Polyethylene Glycol: Evaluation and Validation on Common ImmunoAssay Platforms

Clinical Chemistry ◽

10.1373/clinchem.2008.105312 ◽

2008 ◽

Vol 54 (10) ◽

pp. 1673-1681 ◽

Cited By ~ 67

Author(s):

Luisa Beltran ◽

Michael N Fahie-Wilson ◽

T Joseph McKenna ◽

Lucille Kavanagh ◽

Thomas P Smith

Keyword(s):

Polyethylene Glycol ◽

Reference Data ◽

Gel Filtration ◽

Reference Intervals ◽

Healthy Individuals ◽

Serum Samples ◽

Male And Female ◽

Clinical Laboratories ◽

N 93 ◽

Roche Diagnostics

Abstract Background: Macroprolactin is an important source of immunoassay interference that commonly leads to misdiagnosis and mismanagement of hyperprolactinemic patients. We used the predominant immunoassay platforms for prolactin to assay serum samples treated with polyethylene glycol (PEG) and establish and validate reference intervals for total and monomeric prolactin. Methods: We used the Architect (Abbott), ADVIA Centaur and Immulite (Siemens Diagnostics), Access (Beckman Coulter), Elecsys (Roche Diagnostics), and AIA (Tosoh) analyzers with samples from healthy males (n = 53) and females (n = 93) to derive parametric reference intervals for total and post-PEG monomeric prolactin. Concentrations of immunoreactive prolactin isoforms in serum samples from healthy individuals were established by gel filtration chromatography (GFC). We then used samples from 22 individuals whose hyperprolactinemia was entirely attributable to macroprolactin and 32 patients with true hyperprolactinemia to compare patient classifications and prolactin concentrations measured by GFC with the newly derived post-PEG reference intervals. Results: Parametric reference intervals for post-PEG prolactin in male and female serum samples, respectively, were (in mIU/L): 61–196, 66–278 (Centaur); 63–245, 75–381 (Elecsys); 70–301, 92–469 (Access); 72–229, 79–347 (Architect); 73–247, 83–383 (AIA); and 78–263, 85–394 (Immulite). Concordance between GFC and immunoassay-specific post-PEG reference intervals was observed in 311 of 324 cases and for 31 of 32 patients with true hyperprolactinemia and 17 of 22 patients with macroprolactinemia. Results leading to misclassification occurred in a few analyzers for 5 macroprolactinemia patient samples with relatively minor increases in post-PEG prolactin (mean 61 mIU/L). Conclusions: Our validated normative reference data for sera pretreated with PEG and analyzed on the most commonly used immunoassay platforms should facilitate the more widespread introduction of macroprolactin screening by clinical laboratories.

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Neurofilament medium polypeptide (NFM) protein concentration is increased in CSF and serum samples from patients with brain injury

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2014-0908 ◽

2015 ◽

Vol 53 (10) ◽

Cited By ~ 25

Author(s):

Eduardo Martínez-Morillo ◽

Charmaine Childs ◽

Belén Prieto García ◽

Francisco V. Álvarez Menéndez ◽

Alexander D. Romaschin ◽

...

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Brain Damage ◽

Medical Condition ◽

Size Exclusion ◽

Medical Emergency ◽

Healthy Individuals ◽

Serum Samples ◽

Coefficients Of Variation ◽

Exclusion Chromatography

AbstractBrain injury is a medical emergency that needs to be diagnosed and treated promptly. Several proteins have been studied as biomarkers of this medical condition. The aims of this study were to: 1) evaluate the selectivity and precision of a commercial ELISA kit for neurofilament medium polypeptide (NFM) protein; and 2) evaluate the concentration in cerebrospinal fluid (CSF) and serum of healthy individuals and patients with brain damage.An ELISA from Elabscience was used. The selectivity was evaluated using size-exclusion chromatography and mass spectrometry. Intra- and inter-batch coefficients of variation (CV) were also studied. Fifty-one CSF samples from 36 age-matched patients with hemorrhagic stroke (HS) (n=30), ischemic stroke (IS) (n=11) and healthy individuals (n=10) were assayed. In addition, serum samples from healthy volunteers (n=47), 68 serum samples from seven patients with HS, 106 serum samples from 12 patients with traumatic brain injury (TBI) and 68 serum samples from 68 patients with mild traumatic brain injury (mTBI) were also analyzed.NFM was identified in the chromatographic fraction with highest immunoreactivity. The intra- and inter-batch CVs were ≤10% and ≤13%, respectively. The CSF-NFM concentration in HS was significantly higher (p<0.0001) than in IS and controls. Serum NFM concentration ranged from 0.26 to 8.57 ng/mL in healthy individuals (median=2.29), from 0.97 to 42.4 ng/mL in HS (median=10.8) and from 3.48 to 45.4 ng/mL in TBI (median=14.7). Finally, 44% of patients with mTBI had increased NFM concentration, with significantly higher levels (p=0.01) in patients with polytrauma.To our knowledge this is the first study describing increased NFM levels in CSF and serum from patients with brain damage.

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Intra- and inter-cycle variability of anti-Müllerian hormone (AMH) levels in healthy women during non-consecutive menstrual cycles: the BICYCLE study

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2021-0698 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Marieke Biniasch ◽

Ruediger Paul Laubender ◽

Martin Hund ◽

Katharina Buck ◽

Christian De Geyter

Keyword(s):

Biological Variability ◽

Single Cycle ◽

Serum Samples ◽

Menstrual Cycles ◽

Healthy Women ◽

Analytical Variability ◽

Coefficients Of Variation ◽

Periodic Regression ◽

Roche Diagnostics ◽

Gonadotropin Dosage

Abstract Objectives Determine variability of serum anti-Müllerian hormone (AMH) levels during ovulatory menstrual cycles between different women (inter-participant), between non-consecutive cycles (inter-cycle) and within a single cycle (intra-cycle) in healthy women. Methods Eligible participants were women aged 18–40 years with regular ovulatory menstrual cycles. Serum samples were collected every second day during two non-consecutive menstrual cycles. AMH levels were measured in triplicate using the Elecsys® AMH Plus immunoassay (Roche Diagnostics). AMH level variability was evaluated using mixed-effects periodic regression models based on Fourier series. The mesor was calculated to evaluate inter-participant and inter-cycle variability. Inter- and intra-cycle variability was evaluated using peak-to-peak amplitudes. Separation of biological and analytical coefficients of variation (CVs) was determined by analysing two remeasured AMH levels (with and without original AMH levels). Results A total of 47 women were included in the analysis (42 assessed over two cycles; five one cycle only). CV of unexplained biological variability was 9.61%; analytical variability was 3.46%. Inter-participant variability, given by time-series plots of AMH levels, was greater than inter-cycle variability. Between individual participants, both mesor and peak-to-peak amplitudes proved variable. In addition, for each participant, intra-cycle variability was higher than inter-cycle variability. Conclusions Inter-participant and intra-cycle variability of AMH levels were greater than inter-cycle variability. Unexplained biological variability was higher than analytical variability using the Elecsys AMH Plus immunoassay. Understanding variability in AMH levels may aid in understanding differences in availability of antral ovarian follicles during the menstrual cycle, which may be beneficial in designing gonadotropin dosage for assisted reproductive technology.

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Automated Measurement of 25-OH Vitamin D3 on the Roche Modular E170 Analyzer

Clinical Chemistry ◽

10.1373/clinchem.2008.111732 ◽

2008 ◽

Vol 54 (12) ◽

pp. 2059-2062 ◽

Cited By ~ 57

Author(s):

Aila Leino ◽

Ursula Turpeinen ◽

Pertti Koskinen

Keyword(s):

Vitamin D3 ◽

Tandem Mass ◽

Plasma Samples ◽

Automated Measurement ◽

Serum Samples ◽

Chromatography Tandem Mass Spectrometry ◽

Liquid Chromatography Tandem Mass ◽

Electrochemiluminescence Immunoassay ◽

Automated Immunoassay ◽

Roche Diagnostics

AbstractBackground: The first commercial direct automated immunoassay specific for 25-OH vitamin D3 (25-OH-D3) was recently introduced for use on Roche Diagnostics immunoassay analyzers. We assessed the analytical performance of the Elecsys 25-OH-D3 assay on a Roche Modular E 170 analyzer.Methods: The Elecsys 25-OH-D3 assay is a direct electrochemiluminescence immunoassay for human serum or plasma. It is a competitive assay in which the binding protein of vitamin D is inactivated during incubation. The assay employs a polyclonal antibody directed against 25-OH vitamin D3. We compared the 25-OH-D3 assay to assays performed with RIA, HPLC, and liquid chromatography–tandem mass spectrometry (LC-MS/MS).Results: At concentrations of 48, 76, and 124 nmol/L, within-run CVs were 5.1%, 3.1%, and 7.1% and total CVs were 12.1%, 7.4%, and 10.6%, respectively. A comparison of Elecsys 25-OH vitamin D3 with RIA yielded the regression equation: Elecsys = 1.114 × RIA – 6.15 (Sy|x = 15.7 nmol/L; n = 163). The corresponding equation with HPLC was: Elecsys = 1.077 × HPLC + 5.442 (Sy|x = 13.9 nmol/L; n = 67) and with LC-MS/MS: Elecsys = 0.887 × LC-MS/MS + 5.046 (Sy|x =12.4 nmol/L; n = 64). Contrary to LC-MS/MS, with the cutoff of 50 nmol/L (deficiency vs normal), approximately 10% of samples were misclassified as normal with RIA and Elecsys. Plasma samples were observed to have markedly higher concentrations than serum samples.Conclusions: The Elecsys concentrations of 25-OH-D3 were in good overall agreement with those determined with LC-MS/MS and RIA. However, large between-method variation was observed in individual patient samples. Use of serum rather than plasma is preferred owing to the higher results observed with plasma samples.

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Serological and molecular studies on subclinical hepatitis E virus infection using periodic serum samples obtained from healthy individuals

Journal of Medical Virology ◽

10.1002/jmv.20393 ◽

2005 ◽

Vol 76 (4) ◽

pp. 526-533 ◽

Cited By ~ 33

Author(s):

Takehiro Mitsui ◽

Yukie Tsukamoto ◽

Shigeru Suzuki ◽

Chikao Yamazaki ◽

Kazuo Masuko ◽

...

Keyword(s):

Virus Infection ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Healthy Individuals ◽

Serum Samples ◽

Molecular Studies

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COVID-19 Vaccine mRNABNT162b2 Elicits Human Antibody Response in Milk of Breastfeeding Women

Vaccines ◽

10.3390/vaccines9070785 ◽

2021 ◽

Vol 9 (7) ◽

pp. 785

Author(s):

Maurizio Guida ◽

Daniela Terracciano ◽

Michele Cennamo ◽

Federica Aiello ◽

Evelina La Civita ◽

...

Keyword(s):

Breast Milk ◽

Antibody Response ◽

Human Milk ◽

Human Antibody ◽

Serum Antibodies ◽

Serum Samples ◽

Low Concentration ◽

Milk Samples ◽

Milk Antibodies ◽

Roche Diagnostics

Objective: The objective of this research is to demonstrate the release of SARS-CoV-2 Spike (S) antibodies in human milk samples obtained by patients who have been vaccinated with mRNABNT162b2 vaccine. Methods: Milk and serum samples were collected in 10 volunteers 20 days after the first dose and 7 seven days after the second dose of the mRNABNT162b2 vaccine. Anti-SARS-CoV-2 S antibodies were measured by the Elecsys® Anti-SARS-CoV-2 S ECLIA assay (Roche Diagnostics AG, Rotkreuz, Switzerland), a quantitative electrochemiluminescence immunometric method. Results: At first sample, anti-SARS-CoV-2 S antibodies were detected in all serum samples (103.9 ± 54.9 U/mL) and only in two (40%) milk samples with a low concentration (1.2 ± 0.3 U/mL). At the second sample, collected 7 days after the second dose, anti-SARS-CoV-2 S antibodies were detected in all serum samples (3875.7 ± 3504.6 UI/mL) and in all milk samples (41.5 ± 47.5 UI/mL). No correlation was found between the level of serum and milk antibodies; the milk antibodies/serum antibodies ratio was on average 2% (range: 0.2–8.4%). Conclusion: We demonstrated a release of anti-SARS-CoV-2 S antibodies in the breast milk of women vaccinated with mRNABNT162b2. Vaccinating breastfeeding women could be a strategy to protect their infants from COVID-19 infection.

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