The harmonization of cardiac troponin I measurement is independent of sample time collection but is dependent on the source of calibrator

Tate, Jillian R.; Heathcote, David; Koerbin, Gus; Thean, Gary; Andriske, David; Bonar, John R.; Gill, Janice

doi:10.1016/s0009-8981(02)00214-0

Cited by 17 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…At the analytical level, various antibodies used in the measurement systems recognize different epitopes with varying avidity and crossreactivity. The search should continue for a reference material; however, identification of a common calibrating material suitable for standardization of all cTnI methods will be challenging because specimen-dependent variations in cTnI values were found for measurements performed on different cTnI systems that could not be accounted for by calibration differences or by time of specimen collection (22,23 ). Although identifying a common calibrating material is important, the primary clinical concern is harmonization of results, i.e., consistency and reliability for interpretation of patient measurements and clinical trial results (24 ).…”

Section: Discussionmentioning

confidence: 99%

Toward Standardization of Cardiac Troponin I Measurements Part II: Assessing Commutability of Candidate Reference Materials and Harmonization of Cardiac Troponin I Assays

Christenson

2006

Clinical Chemistry

View full text Add to dashboard Cite

Background: Cardiac tropoin I (cTnI) measurementsshow an ϳ20-to 40-fold difference between assays, and better standardization and harmonization are needed. Toward this goal, the AACC cTnI Standardization Committee collaborated with the National Institute of Standards and Technology (NIST) in an earlier study to select 2 candidate reference materials (cRMs). Methods: Two troponin cRMs, a troponin C-troponin I-troponin T (CIT) complex from human heart tissue and a CIT complex from recombinant technology, were

show abstract

Section: Discussionmentioning

confidence: 99%

Toward Standardization of Cardiac Troponin I Measurements Part II: Assessing Commutability of Candidate Reference Materials and Harmonization of Cardiac Troponin I Assays

Christenson

2006

Clinical Chemistry

View full text Add to dashboard Cite

show abstract

“…Proteolysis of cTnI has been shown to lead to detection difficulties when antibodies against proteolytically cleaved regions are used (8 -10 ). Variations in cTnI assay results are also partly attributable to different calibrators that most likely differ from the actual analyte (11 ). This leads to what is probably the most important source of assay discrepancies: the analyte itself.…”

mentioning

confidence: 99%

Strategy for Analysis of Cardiac Troponins in Biological Samples with a Combination of Affinity Chromatography and Mass Spectrometry

Labugger¹,

Simpson²,

Quick³

et al. 2003

Clinical Chemistry

View full text Add to dashboard Cite

Background: Cardiac troponins are modified during ischemic injury and are found as a heterogeneous mixture in blood of patients with cardiovascular diseases. We present a strategy to isolate cardiac troponins from human biological material, by use of affinity chromatography, and to provide samples ready for direct analysis by mass spectrometry. Methods: Cardiac troponins were isolated from human left ventricular tissue by affinity chromatography. Isolated troponins were either eluted and analyzed by Western blot or enzymatically digested while bound to affinity beads. The resulting peptide mixture was subjected to mass spectrometry for protein identification and characterization. The same method was used to analyze serum from patients with acute myocardial infarction (AMI). Results: Affinity chromatography with antibodies specific for one cardiac troponin subunit facilitated the isolation of the entire cardiac troponin complex from myocardial tissue. The three different proteases used for enzymatic digestion increased the total protein amino acid sequence coverage by mass spectrometry for the three cardiac troponin subunits. Combined amino acid sequence coverages for cardiac troponin I, T, and C (cTnI, cTnT, cTnC) were 54%, 48%, and 40%, respectively. To simulate matrix effects on the affinity chromatography-mass spectrometry approach, we diluted tissue homogenate in cardiac troponin-free serum. Sequence coverages in this case were 44%, 41%, and 19%, respectively. Finally, affinity chromatography-mass

show abstract

“…Other studies have reported a sample-dependent variation that does occur for cTnI measurement probably reflecting differences in cTnI isoforms for some samples and different assay reactivity [12,24]. Using cTnI assays available in the late 1990s Wu et al showed that while assays recognized both the complexed and free cTnI forms, some did not give equal relative responses to the various forms of cTnI, hence resulting in over-or under-estimation of the cTnI concentration in patient samples [25].…”

Section: Discussionmentioning

confidence: 99%

“…This approach, for which a commutable CRM is available, has been applied to the standardization of various proteins, including quite recently cystatin C [10]. Several studies have shown that serum-based cTnI-positive materials could be used in assay calibration to reduce the difference in cTnI results between routine assays [6,11,12]. In the AACC study, result equivalence was observed after the mathematical realignment of values against the median cTnI concentrations of six pools, the variability of results among cTnI assays decreasing from CVs of approximately 90% to CVs of 7%-28% [6].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of standardization capability of current cardiac troponin I assays by a correlation study: results of an IFCC pilot project

Tate

Bunk

Christenson

et al. 2015

Clinical Chemistry and Laboratory Medicine (CCLM)

View full text Add to dashboard Cite

Background: As a part of an International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) project to prepare a commutable reference material for cardiac troponin I (cTnI), a pilot study evaluated current cTnI assays for measurement equivalence and their standardization capability. Methods: cTnI-positive samples collected from 90 patients with suspected acute myocardial infarction were assessed for method comparison by 16 cTnI commercial assays according to predefined testing protocols. Seven serum pools prepared from these samples were also assessed. Results: Each assay was assessed against median cTnI concentrations measured by 16 cTnI assays using PassingBablok regression analysis of 79 patient samples with values above each assay's declared detection limit. We

show abstract

The harmonization of cardiac troponin I measurement is independent of sample time collection but is dependent on the source of calibrator

Cited by 17 publications

References 17 publications

Toward Standardization of Cardiac Troponin I Measurements Part II: Assessing Commutability of Candidate Reference Materials and Harmonization of Cardiac Troponin I Assays

Toward Standardization of Cardiac Troponin I Measurements Part II: Assessing Commutability of Candidate Reference Materials and Harmonization of Cardiac Troponin I Assays

Strategy for Analysis of Cardiac Troponins in Biological Samples with a Combination of Affinity Chromatography and Mass Spectrometry

Evaluation of standardization capability of current cardiac troponin I assays by a correlation study: results of an IFCC pilot project

Contact Info

Product

Resources

About