Mass concentration and activity concentration of creatine kinase isoenzyme MB compared in serum after acute myocardial infarction

1990 ◽  
Vol 36 (1) ◽  
pp. 149-153 ◽  
Author(s):  
J R Delanghe ◽  
A M De Mol ◽  
M L De Buyzere ◽  
I K De Scheerder ◽  
R J Wieme
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Creatine Kinase ◽  
Catalytic Activity ◽  
Conformational Changes ◽  
Mass Concentration ◽  
Activity Concentration ◽  
Steady Increase ◽  
Reference Limit ◽  
Upper Reference Limit

Abstract We compared three current methods (immunoinhibition, "Isomune-CK" immunoprecipitation, and the Tandem-E CKMB II immunoenzymometric assay) for determination of creatine kinase (CK; EC 2.7.3.2) isoenzyme MB in serum. Although results inter-correlated well, the immunoinhibition assay gave higher activity values. Atypical CK forms did not interfere with the immunoprecipitation and immunoenzymometric methods. In acute myocardial infarction the catalytic properties of CK decreased with the enzyme's age, as reflected by a steady increase in activation energy of the catalyzed reaction. In septicemia patients with very low CK and CK-MB catalytic activity, mean CK-MB mass concentration exceeded the upper reference limit, suggesting an increased rate of loss of activity concentration in these patients' sera. Because of the assay's lesser susceptibility to conformational changes at the active site of the enzyme, we suggest that measurement of CK-MB mass concentration is better suited for infarct sizing than measurement of catalytic activity.

Early detection of acute myocardial infarction by measurement of mass concentration of creatine kinase-MB

1991 ◽  
Vol 68 (17) ◽  
pp. 1545-1550 ◽  
Author(s):  
Johannes Mair ◽  
Erika Artner-Dworzak ◽  
Anton Dienstl ◽  
Peter Lechleitner ◽  
Bernhard Morass ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Creatine Kinase ◽  
Early Detection ◽  
Mass Concentration ◽  
Creatine Kinase Mb

A novel troponin I rule-out value below the upper reference limit for acute myocardial infarction

Heart ◽  
2016 ◽  
Vol 102 (21) ◽  
pp. 1721-1727 ◽  
Author(s):  
Susan M I Goorden ◽  
Rudi A van Engelen ◽  
Liza S M Wong ◽  
Tjeerd van der Ploeg ◽  
Gerard J E Verdel ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Troponin I ◽  
Reference Limit ◽  
Upper Reference Limit ◽  
Rule Out

scholarly journals Contribution of creatine kinase MB mass concentration at admission to early diagnosis of acute myocardial infarction.

Heart ◽  
1994 ◽  
Vol 72 (2) ◽  
pp. 112-118 ◽  
Author(s):  
A J Bakker ◽  
J P Gorgels ◽  
B van Vlies ◽  
M J Koelemay ◽  
R Smits ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Creatine Kinase ◽  
Early Diagnosis ◽  
Mass Concentration ◽  
Creatine Kinase Mb

Analytical evaluation of a sensitive enzyme immunoassay for determinations of creatine kinase isoenzyme MB

1990 ◽  
Vol 36 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
P J Jørgensen ◽  
M Hørder ◽  
J Selmer ◽  
H E Bøtker
Keyword(s):  
Myocardial Infarction ◽  
Creatine Kinase ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Myocardial Damage ◽  
Reference Interval ◽  
Reference Limit ◽  
B Subunit ◽  
Myocardial Diseases ◽  
Upper Reference Limit

Abstract We have evaluated a new sensitive immunometric assay for the determination of creatine kinase (CK; EC 2.7.3.2) MB isoenzyme (NovoClone CK-MB), involving an enzyme label and two monoclonal antibodies directed against the B subunit and the M subunit, respectively. The anti-CK-B antibodies are bound to the solid phase. The assay was modified to be extremely sensitive and thus to measure the concentration range below and close to the cutoff value used for the diagnosis of myocardial infarction. A reference interval of 0-6 micrograms/L was found for 315 outpatients without myocardial diseases (132 men and 183 women); the overall median of the log-gaussian distribution was 1.91 micrograms/L (2.03 and 1.79 micrograms/L for men and women, respectively). Total and within-assay imprecision (CV) was less than 6% at the upper reference limit. The detection limit was 0.1 microgram/L. The assay provides a favorable signal-to-noise ratio: the calibrators 0.0, 2.0, and 30.0 micrograms/L give absorbances at 492 nm of 0.040, 0.140, and 1.600 A. respectively. We conclude that the assay provides biochemical identification of individuals with myocardial damage but without myocardial infarction.

Concordance of creatine kinase-MB activity and mass.

1989 ◽  
Vol 35 (3) ◽  
pp. 440-443 ◽  
Author(s):  
P R Eisenberg ◽  
D Shaw ◽  
C Schaab ◽  
A S Jaffe
Keyword(s):  
Myocardial Infarction ◽  
Creatine Kinase ◽  
Monoclonal Antibodies ◽  
Mass Concentration ◽  
Activity Concentration ◽  
Cardiac Care ◽  
Activity Concentrations ◽  
Creatine Kinase Mb ◽  
The Relationship ◽  
Cardiac Care Unit

Abstract The recent availability of monoclonal antibodies that are highly specific for creatine kinase (CK; EC 2.7.3.2) MB isoenzyme should allow for the development of rapid, sensitive, and specific assays of CK-MB mass and activity. However, the relationship between the mass concentration of CK-MB and its activity in plasma has previously been thought by some to be variable. To determine the extent to which discrepancies of potential clinical significance might arise between measurements of activity and mass in plasma, we compared CK-MB activity and concentration in 1298 samples obtained from 226 patients admitted to the cardiac-care unit. CK-MB activity concentration was determined with an immunoadsorption assay, and mass concentration was measured by an automated "sandwich" assay (Magic Lite; Ciba Corning Diagnostics). Both of these assays are based on specific monoclonal antibodies for CK-MB. Values obtained with these assays correlated well (r = 0.94). Normal and abnormal values with the two assays were concordant in 96% of the samples. In all but three instances, differences occurred late after myocardial infarction and were characterized by minimal increases as determined by one method vs values at the upper limit of normal as determined with the other. Thus, measurements of CK-MB mass and activity concentrations in plasma with assays based on these specific monoclonal antibodies are comparable for the detection or exclusion of acute myocardial infarction.

MO175TROPONIN CUT-OFFS FOR ACUTE MYOCARDIAL INFARCTION IN PATIENTS WITH IMPAIRED RENAL FUNCTION - A SYSTEMATIC REVIEW AND META-ANALYSIS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Jan Kampmann ◽  
Jeff Granhøj ◽  
Frans Brandt Kristensen ◽  
Andreas Pedersen ◽  
Christian Backer Mogensen ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Renal Function ◽  
Troponin I ◽  
Troponin T ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Asian Studies ◽  
Reference Limit ◽  
Upper Reference Limit

Abstract Background and Aims Background Identifying acute myocardial infarction in patients with renal disease is notoriously difficult due to atypical presentation and chronically elevated troponin. Aim To generate an optimized troponin cut-off value for patients with impaired renal function and acute myocardial infarction via meta-analysis. Method Two investigators screened 2,580 publications from Medline, Embase, Pubmed, Web of Science and Cochrane library. Only studies that investigated alternative cut-offs according to renal impairment were included. 15 articles fulfilled the inclusion criteria and results were included in a meta-analysis. Study characteristics and cut-off values were extracted. Study quality and risk of bias were assessed by using QUADAS-2 score. Six studies were included in the meta-analysis. To calculate the optimal cut off value in accordance to AUC for troponin T and troponin I in patients with renal impairment a bivariat mixed effect model on the sensitivity and specificity transformed by way of the inverse probit function similar to the model implemented in the R-package diagmeta was employed. Results Review: There was a considerable diversity in study design, study population and endpoint definition. The cut-off value for patients on peritoneal dialyses was twice as high (144 ng/L) when compared to patients on hemodialysis (75 ng/l). Asian studies suggested a substantially higher troponin cut-off when compared to European and American studies. The risk of bias was low in the analyzed studies, yet several studies were considered to have a low applicability. Meta-analysis Cut-off value for troponin T in patients not in dialysis with eGFR <60 ml/min/1.73m2, a troponin T value of 47.89 ng (23.95; 71.83) was found. In patients on dialysis a troponin T value of 239.75 ng/l ( 69.27 ; 410.23) was demonstrated. The 99th percentile of the upper reference limit for troponin T was 14 ng/l. Cut-off value for troponin I: In patients not in dialysis with eGFR < 60 ml/min/1.73m² a troponin I value of 42.45 ng/l ( 33.83 ; 51.08 ) was demonstrated. The 99th percentile of the upper reference limit for troponin I ranged from 9-42 ng/l depending on the assays used. Troponin I cut-off for patients in dialysis could not be calculated due to limited data. Conclusion The new cut-off values could help to identify patients whose troponin suggests acute myocardial infarction rather than renal function related troponin elevation. The meta-analysis is based on only six studies in total. Further subdivision according to eGFR would be desirable in order to optimize troponin cut-off values especially for dialysis patients. A differentiation on troponin cut-offs for HD and PD patients may yield further benefits. Asian studies suggested a substantially higher troponin cut-off when compared to European and American studies. The factors behind these findings may be worth investigating.

Response: a novel troponin I rule-out value below the upper reference limit for acute myocardial infarction

Heart ◽  
2016 ◽  
Vol 102 (21) ◽  
pp. 1772-1772
Author(s):  
Andrew R Chapman ◽  
Atul Anand ◽  
Anoop S V Shah ◽  
Philip D Adamson ◽  
Nicholas L Mills
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Troponin I ◽  
Reference Limit ◽  
Upper Reference Limit ◽  
Rule Out
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