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Riabkova NS, Kogan AE, Katrukha IA, Vylegzhanina AV, Bogomolova AP, Alieva AK, Pevzner DV, Bereznikova AV, Katrukha AG. Influence of Anticoagulants on the Dissociation of Cardiac Troponin Complex in Blood Samples. Int J Mol Sci 2024; 25:8919. [PMID: 39201603 PMCID: PMC11354535 DOI: 10.3390/ijms25168919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 07/31/2024] [Accepted: 08/13/2024] [Indexed: 09/02/2024] Open
Abstract
Immunodetection of cardiac isoforms of troponin I (cTnI) and troponin T (cTnT) in blood samples is widely used for the diagnosis of acute myocardial infarction. The cardiac troponin complex (ITC-complex), comprising cTnI, cTnT, and troponin C (TnC), makes up a large portion of troponins released into the bloodstream after the necrosis of cardiomyocytes. However, the stability of the ITC-complex has not been fully investigated. This study aimed to investigate the stability of the ITC-complex in blood samples. A native ITC-complex was incubated in buffer solutions, serum, and citrate, heparin, or EDTA plasma at various temperatures. Western blotting and gel filtration were performed, and troponins were detected using specific monoclonal antibodies. The ITC-complex dissociated at 37 °C in buffers with or without anticoagulants, in citrate, heparin, and EDTA plasmas, and in serum, into a binary cTnI-TnC complex (IC-complex) and free cTnT. In plasma containing heparin and EDTA, the IC-complex further dissociated into free TnC and cTnI. No dissociation was found at 4 °C or at room temperature (RT) in all matrices within 24 h except for EDTA plasma. After incubation at 37 °C in EDTA plasma and serum, dissociation was accompanied by proteolytic degradation of both cTnI and cTnT. The presence of anti-troponin autoantibodies in the sample impeded dissociation of the ITC-complex. The ITC-complex dissociates in vitro to form the IC-complex and free cTnT at 37 °C but is mostly stable at 4 °C or RT. Further dissociation of the IC-complex occurs at 37 °C in plasmas containing heparin and EDTA.
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Affiliation(s)
- Natalia S. Riabkova
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
- Department of Biochemistry, Faculty of Biology, Moscow State University, Leninskie Gory 1, str. 12, 119234 Moscow, Russia
| | - Alexander E. Kogan
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
- Department of Biochemistry, Faculty of Biology, Moscow State University, Leninskie Gory 1, str. 12, 119234 Moscow, Russia
| | - Ivan A. Katrukha
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
- Department of Biochemistry, Faculty of Biology, Moscow State University, Leninskie Gory 1, str. 12, 119234 Moscow, Russia
| | - Alexandra V. Vylegzhanina
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
| | - Agnessa P. Bogomolova
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
- Department of Biochemistry, Faculty of Biology, Moscow State University, Leninskie Gory 1, str. 12, 119234 Moscow, Russia
| | - Amina K. Alieva
- National Medical Research Centre of Cardiology Named after Academician E.I. Chazov, Akademik Chazov str., 15A, 121552 Moscow, Russia; (A.K.A.); (D.V.P.)
| | - Dmitry V. Pevzner
- National Medical Research Centre of Cardiology Named after Academician E.I. Chazov, Akademik Chazov str., 15A, 121552 Moscow, Russia; (A.K.A.); (D.V.P.)
| | - Anastasia V. Bereznikova
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
- Department of Biochemistry, Faculty of Biology, Moscow State University, Leninskie Gory 1, str. 12, 119234 Moscow, Russia
| | - Alexey G. Katrukha
- HyTest Ltd., Intelligate 1, 6th Floor, Joukahaisenkatu 6, 20520 Turku, Finland; (N.S.R.); (A.E.K.); (A.V.V.); (A.P.B.); (A.V.B.); (A.G.K.)
- Department of Biochemistry, Faculty of Biology, Moscow State University, Leninskie Gory 1, str. 12, 119234 Moscow, Russia
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Jaffe AS. Analysis of Troponin Fragments: The Start of a New Era-Perhaps? Clin Chem 2024; 70:1003-1005. [PMID: 38973023 DOI: 10.1093/clinchem/hvae095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 06/18/2024] [Indexed: 07/09/2024]
Affiliation(s)
- Allan S Jaffe
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, United States
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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Salonen SM, Tuominen TJK, Raiko KIS, Vasankari T, Aalto R, Hellman TA, Lahtinen SE, Soukka T, Airaksinen KEJ, Wittfooth ST. Highly Sensitive Immunoassay for Long Forms of Cardiac Troponin T Using Upconversion Luminescence. Clin Chem 2024; 70:1037-1045. [PMID: 38888909 DOI: 10.1093/clinchem/hvae075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 05/06/2024] [Indexed: 06/20/2024]
Abstract
BACKGROUND Long cardiac troponin T (cTnT) has been proposed to be a promising and more specific biomarker of acute myocardial infarction (AMI). As it represents a subfraction of circulating cTnT, detection of very low concentrations is a requirement. The aim of this study was to develop a novel, highly sensitive immunoassay for long cTnT. METHODS A two-step sandwich-type immunoassay for long cTnT was developed, utilizing upconverting nanoparticles (UCNPs) as reporters. The limits of detection and quantitation were determined for the assay. Linearity and matrix effects were evaluated. Performance with clinical samples was assessed with samples from patients with non-ST elevation myocardial infarction (NSTEMI, n = 30) and end-stage renal disease (ESRD, n = 37) and compared to a previously developed time-resolved fluorescence (TRF)-based long cTnT assay and a commercial high-sensitivity cTnT assay. RESULTS The novel assay reached a 28-fold lower limit of detection (0.40 ng/L) and 14-fold lower limit of quantitation (1.79 ng/L) than the previously developed TRF long cTnT assay. Li-heparin and EDTA plasma, but not serum, were found to be suitable sample matrixes for the assay. In a receiver operating characteristics curve analysis, the troponin ratio (long/total cTnT) determined with the novel assay showed excellent discrimination between NSTEMI and ESRD with an area under the curve of 0.986 (95% CI, 0.967-1.000). CONCLUSIONS By utilizing upconversion luminescence technology, we developed a highly sensitive long cTnT assay. This novel assay can be a valuable tool for investigating the full potential of long cTnT as a biomarker for AMI. ClinicalTrials.gov Registration Number: NCT04465591.
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Affiliation(s)
- Selma M Salonen
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Tuulia J K Tuominen
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Kirsti I S Raiko
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Tuija Vasankari
- Heart Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Rami Aalto
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Tapio A Hellman
- Kidney Center, Turku University Hospital and University of Turku, Turku, Finland
| | - Satu E Lahtinen
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | - Tero Soukka
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
| | | | - Saara T Wittfooth
- Biotechnology Unit, Department of Life Technologies, University of Turku, Turku, Finland
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Riabkova NS, Bogomolova AP, Kogan AE, Katrukha IA, Vylegzhanina AV, Pevzner DV, Alieva AK, Bereznikova AV, Katrukha AG. Interaction of heparin with human cardiac troponin complex and its influence on the immunodetection of troponins in human blood samples. Clin Chem Lab Med 2024; 0:cclm-2024-0066. [PMID: 38738903 DOI: 10.1515/cclm-2024-0066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 04/17/2024] [Indexed: 05/14/2024]
Abstract
OBJECTIVES Heparin is a highly charged polysaccharide used as an anticoagulant to prevent blood coagulation in patients with presumed myocardial infarction and to prepare heparin plasma samples for laboratory tests. There are conflicting data regarding the effects of heparin on the measurement of cardiac isoforms of troponin I (cTnI) and troponin T (cTnT), which are used for the immunodiagnosis of acute myocardial infarction. In this study, we investigated the influence of heparin on the immunodetection of human cardiac troponins. METHODS Gel filtration (GF) techniques and sandwich fluoroimmunoassay were performed. The regions of сTnI and cTnT that are affected by heparin were investigated with a panel of anti-cTnI and anti-cTnT monoclonal antibodies, specific to different epitopes. RESULTS Heparin was shown to bind to the human cardiac full-size ternary troponin complex (ITC-complex) and free cTnT, which increased their apparent molecular weights in GF studies. Heparin did not bind to the low molecular weight ITC-complex and to binary cTnI-troponin С complex. We did not detect any sites on cTnI in the ITC-complex that were specifically affected by heparin. In contrast, cTnT regions limited to approximately 69-99, 119-138 and 145-164 amino acid residues (aar) in the ITC-complex and a region that lies approximately between 236 and 255 aar of free cTnT were prone to heparin influence. CONCLUSIONS Heparin binds to the ITC-complex via cTnT, interacting with several sites on the N-terminal and/or central parts of the cTnT molecule, which might influence the immunodetection of analytes in human blood.
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Affiliation(s)
- Natalia S Riabkova
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Agnessa P Bogomolova
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Alexander E Kogan
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Ivan A Katrukha
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | | | - Dmitry V Pevzner
- National Medical Research Centre of Cardiology Named After Academician E.I. Chazov, Moscow, Russia
| | - Amina K Alieva
- National Medical Research Centre of Cardiology Named After Academician E.I. Chazov, Moscow, Russia
| | - Anastasia V Bereznikova
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Alexey G Katrukha
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
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Bollen Pinto B, Ackland GL. Pathophysiological mechanisms underlying increased circulating cardiac troponin in noncardiac surgery: a narrative review. Br J Anaesth 2024; 132:653-666. [PMID: 38262855 DOI: 10.1016/j.bja.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 11/23/2023] [Accepted: 12/15/2023] [Indexed: 01/25/2024] Open
Abstract
Assay-specific increases in circulating cardiac troponin are observed in 20-40% of patients after noncardiac surgery, depending on patient age, type of surgery, and comorbidities. Increased cardiac troponin is consistently associated with excess morbidity and mortality after noncardiac surgery. Despite these findings, the underlying mechanisms are unclear. The majority of interventional trials have been designed on the premise that ischaemic cardiac disease drives elevated perioperative cardiac troponin concentrations. We consider data showing that elevated circulating cardiac troponin after surgery could be a nonspecific marker of cardiomyocyte stress. Elevated concentrations of circulating cardiac troponin could reflect coordinated pathological processes underpinning organ injury that are not necessarily caused by ischaemia. Laboratory studies suggest that matching of coronary artery autoregulation and myocardial perfusion-contraction coupling limit the impact of systemic haemodynamic changes in the myocardium, and that type 2 ischaemia might not be the likeliest explanation for cardiac troponin elevation in noncardiac surgery. The perioperative period triggers multiple pathological mechanisms that might cause cardiac troponin to cross the sarcolemma. A two-hit model involving two or more triggers including systemic inflammation, haemodynamic strain, adrenergic stress, and autonomic dysfunction might exacerbate or initiate acute myocardial injury directly in the absence of cell death. Consideration of these diverse mechanisms is pivotal for the design and interpretation of interventional perioperative trials.
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Affiliation(s)
- Bernardo Bollen Pinto
- Division of Anaesthesiology, Department of Anaesthesiology, Pharmacology, Intensive Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland.
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
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Gokhan I, Dong W, Grubman D, Mezue K, Yang D, Wang Y, Gandhi PU, Kwan JM, Hu JR. Clinical Biochemistry of Serum Troponin. Diagnostics (Basel) 2024; 14:378. [PMID: 38396417 PMCID: PMC10887818 DOI: 10.3390/diagnostics14040378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Accurate measurement and interpretation of serum levels of troponin (Tn) is a central part of the clinical workup of a patient presenting with chest pain suspicious for acute coronary syndrome (ACS). Knowledge of the molecular characteristics of the troponin complex and test characteristics of troponin measurement assays allows for a deeper understanding of causes of false positive and false negative test results in myocardial injury. In this review, we discuss the molecular structure and functions of the constituent proteins of the troponin complex (TnT, TnC, and TnI); review the different isoforms of Tn and where they are from; survey the evolution of clinical Tn assays, ranging from first-generation to high-sensitivity (hs); provide a primer on statistical interpretation of assay results based on different clinical settings; and discuss potential causes of false results. We also summarize the advances in technologies that may lead to the development of future Tn assays, including the development of point of care assays and wearable Tn sensors for real-time continuous measurement.
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Affiliation(s)
- Ilhan Gokhan
- Yale School of Medicine, Yale University, New Haven, CT 06510, USA; (I.G.)
| | - Weilai Dong
- Yale School of Medicine, Yale University, New Haven, CT 06510, USA; (I.G.)
| | - Daniel Grubman
- Yale School of Medicine, Yale University, New Haven, CT 06510, USA; (I.G.)
| | - Kenechukwu Mezue
- Section of Cardiovascular Medicine, Yale School of Medicine, Yale University, New Haven, CT 06510, USA (J.M.K.)
| | - David Yang
- Department of Emergency Medicine, Yale School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Yanting Wang
- Division of Cardiovascular Disease and Hypertension, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA
| | - Parul U. Gandhi
- Section of Cardiovascular Medicine, Yale School of Medicine, Yale University, New Haven, CT 06510, USA (J.M.K.)
| | - Jennifer M. Kwan
- Section of Cardiovascular Medicine, Yale School of Medicine, Yale University, New Haven, CT 06510, USA (J.M.K.)
| | - Jiun-Ruey Hu
- Section of Cardiovascular Medicine, Yale School of Medicine, Yale University, New Haven, CT 06510, USA (J.M.K.)
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Henrik Kristensen J, Amalie Wistisen Koczulab C, Anton Frandsen E, Bo Hasselbalch R, Strandkjær N, Jørgensen N, Østergaard M, Hasse Møller-Sørensen P, Christian Nilsson J, Afzal S, Rørbæk Kamstrup P, Dahl M, Bor MV, Frikke-Schmidt R, Rye Jørgensen N, Rode L, Holmvang L, Kjærgaard J, Evi Bang L, Forman J, Dalhoff K, Bundgaard H, Karmark Iversen K. Kinetics of cardiac troponin and other biomarkers in patients with ST elevation myocardial infarction. IJC HEART & VASCULATURE 2023; 48:101250. [PMID: 37602285 PMCID: PMC10432699 DOI: 10.1016/j.ijcha.2023.101250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023]
Abstract
Objective To examine changes in concentration, time-to-peak and the ensuing half-life of cardiac biomarkers in patients with myocardial infarction. Methods Blood sampling was performed every third hour within 24 h after percutaneous coronary intervention (PCI) on a cohort of patients with ST elevation myocardial infarction. Cardiac troponin (cTn) was measured by the Dimension Vista, Vitros, Atellica, and Alinity high-sensitivity (hs) cTnI assays, and the Elecsys hs-cTnT assay. Further, creatine kinase (CK), myoglobin, creatine kinase MB (CKMB) and other biomarkers were analyzed. Results A total of 36 patients completed blood sampling (median age 60 years, IQR 56.4-66.5 years; seven women, 19.4%). Hs-cTnI measured by the Vitros assay was the first hs-cTn to peak at 9.1 h (95%-CI 6.2-10.1) after PCI and 11.7 h (95%-CI 10.4-14.8) after symptoms onset. There were no notable differences between hs-cTn assays in regard to time-to-peak. Also, Vitros hs-cTnI reached the highest median ratio of concentration to upper reference level of nearly 2,000. The median half-life from peak concentration ranged from 7.6 h for myoglobin (CI 6.8-8.6) to 17.8 h for CK (CI 6.8-8.6). For hs-cTn assays the median T½ ranged from 12.4 h for the Vista hs-cTnI assay (95%-CI 11.0-14.1 h) to 17.3 h for the Elecsys hs-cTnT (95%-CI 14.9-20.8 h). Conclusions This study updates knowledge on the kinetics of cardiac biomarkers in current clinical use. There was no notable difference in trajectories, time-to-peak or half-life between hs-cTn assays.
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Affiliation(s)
- Jonas Henrik Kristensen
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Clara Amalie Wistisen Koczulab
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
| | - Emil Anton Frandsen
- Department of Cardiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Rasmus Bo Hasselbalch
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Nina Strandkjær
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Nicoline Jørgensen
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
| | - Morten Østergaard
- Department of Cardiothoracic Anaesthesiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Peter Hasse Møller-Sørensen
- Department of Cardiothoracic Anaesthesiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Jens Christian Nilsson
- Department of Cardiothoracic Anaesthesiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Shoaib Afzal
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Clinical Biochemistry, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
| | - Pia Rørbæk Kamstrup
- Department of Clinical Biochemistry, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
| | - Morten Dahl
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Clinical Biochemistry, Zealand University Hospital – Køge, Lykkebækvej 1, 4600 Køge, Denmark
| | - Mustafa Vakur Bor
- Department of Clinical Biochemistry, University Hospital of Southern Denmark, Finsensgade 35, 6700 Esbjerg, Denmark
| | - Ruth Frikke-Schmidt
- Department of Clinical Biochemistry, Copenhagen University Hospital – Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Niklas Rye Jørgensen
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Clinical Biochemistry, Copenhagen University Hospital – Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Line Rode
- Department of Clinical Biochemistry, Copenhagen University Hospital – Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Lene Holmvang
- Department of Cardiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Jesper Kjærgaard
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Cardiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Lia Evi Bang
- Department of Cardiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Julie Forman
- Section of Biostatistics, Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, 1353 Copenhagen, Denmark
| | - Kim Dalhoff
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Clinical Pharmacology, Copenhagen University Hospital – Bispebjerg and Frederiksberg, Bispebjerg Bakke 23, 2400 Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Department of Cardiology, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Kasper Karmark Iversen
- Department of Cardiology, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Emergency Medicine, Copenhagen University Hospital - Herlev and Gentofte, Borgmester Ib Juuls vej 1, 2730 Herlev, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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Luo Y, Pehrsson M, Langholm L, Karsdal M, Bay-Jensen AC, Sun S. Lot-to-Lot Variance in Immunoassays-Causes, Consequences, and Solutions. Diagnostics (Basel) 2023; 13:diagnostics13111835. [PMID: 37296687 DOI: 10.3390/diagnostics13111835] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 05/05/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
Immunoassays, which have gained popularity in clinical practice and modern biomedical research, play an increasingly important role in quantifying various analytes in biological samples. Despite their high sensitivity and specificity, as well as their ability to analyze multiple samples in a single run, immunoassays are plagued by the problem of lot-to-lot variance (LTLV). LTLV negatively affects assay accuracy, precision, and specificity, leading to considerable uncertainty in reported results. Therefore, maintaining consistency in technical performance over time presents a challenge in reproducing immunoassays. In this article, we share our two-decade-long experience and delve into the reasons for and locations of LTLV, as well as explore methods to mitigate its effects. Our investigation identifies potential contributing factors, including quality fluctuation in critical raw materials and deviations in manufacturing processes. These findings offer valuable insights to developers and researchers working with immunoassays, emphasizing the importance of considering lot-to-lot variance in assay development and application.
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Affiliation(s)
- Yunyun Luo
- Biomarkers and Research, Nordic Bioscience, 2730 Herlev, Denmark
| | - Martin Pehrsson
- Biomarkers and Research, Nordic Bioscience, 2730 Herlev, Denmark
| | - Lasse Langholm
- Biomarkers and Research, Nordic Bioscience, 2730 Herlev, Denmark
| | - Morten Karsdal
- Biomarkers and Research, Nordic Bioscience, 2730 Herlev, Denmark
| | | | - Shu Sun
- Biomarkers and Research, Nordic Bioscience, 2730 Herlev, Denmark
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Katrukha IA, Riabkova NS, Kogan AE, Vylegzhanina AV, Mukharyamova KS, Bogomolova AP, Zabolotskii AI, Koshkina EV, Bereznikova AV, Katrukha AG. Fragmentation of human cardiac troponin T after acute myocardial infarction. Clin Chim Acta 2023; 542:117281. [PMID: 36918061 DOI: 10.1016/j.cca.2023.117281] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/18/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023]
Abstract
BACKGROUND Blood measurement of cardiac troponin T (cTnT) is one of the most widespread methods of acute myocardial infarction (MI) diagnosis. cTnT degradation may have a significant influence on the precision of cTnT immunodetection; however, there are no consistent data describing the level and sites of cTnT proteolysis in the blood of MI patients. In this study, we bordered major cTnT fragments and quantified their relative abundance in the blood at different times after MI. METHODS Serial heparin plasma samples were collected from 37 MI patients 2-37 h following the onset of MI. cTnT and its fragments were studied by western blotting and immunofluorescence analysis using monoclonal antibodies specific to various cTnT epitopes. RESULTS cTnT was present in the blood of MI patients as 23 proteolytic fragments with an apparent molecular mass of ∼ 8-37 kDa. Two major sites of cTnT degradation were identified: between amino acid residues (aar) 68 and 69 and between aar 189 and 223. Analysis of the abundance of cTnT fragments showed an increase in the fraction of free central fragments in the first few hours after MI, while the fraction of the C-terminal fragments of cTnT remained almost unchanged. CONCLUSION cTnT progressively degrades after MI and appears in the blood as a mixture of 23 proteolytic fragments. The cTnT region approximately bordered by aar 69-158 is a promising target for antibodies used for measurement of total cTnT.
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Affiliation(s)
- Ivan A Katrukha
- HyTest Ltd., Turku, Finland; Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia.
| | - Natalia S Riabkova
- HyTest Ltd., Turku, Finland; Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia
| | - Alexander E Kogan
- HyTest Ltd., Turku, Finland; Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia
| | | | | | - Agnessa P Bogomolova
- HyTest Ltd., Turku, Finland; Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia
| | - Artur I Zabolotskii
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia
| | | | - Anastasia V Bereznikova
- HyTest Ltd., Turku, Finland; Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia
| | - Alexey G Katrukha
- HyTest Ltd., Turku, Finland; Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russia
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10
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Hu X, Gao X, Chen S, Guo J, Zhang Y. DropLab: an automated magnetic digital microfluidic platform for sample-to-answer point-of-care testing-development and application to quantitative immunodiagnostics. MICROSYSTEMS & NANOENGINEERING 2023; 9:10. [PMID: 36644334 PMCID: PMC9833028 DOI: 10.1038/s41378-022-00475-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 11/24/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
In point-of-care testing (POCT), tests are performed near patients and results are given rapidly for timely clinical decisions. Immunodiagnostic assays are one of the most important analyses for detecting and quantifying protein-based biomarkers. However, existing POCT immunodiagnostics mainly rely on the lateral flow assay (LFA), which has limited sensitivity or quantification capability. Although other immunodiagnostic assays, such as enzyme-linked immunosorbent assays (ELISAs), offer more sensitive and quantitative results, they require complex liquid manipulations that are difficult to implement in POCT settings by conventional means. Here, we show the development of DropLab, an automated sample-in-answer-out POCT immunodiagnostic platform based on magnetic digital microfluidic (MDM) technology. DropLab performs microbead-based ELISA in droplets to offer more sensitive and quantitative testing results. The intricate liquid manipulations required for ELISA are accomplished by controlling droplets with magnetic microbeads using MDM technology, which enables us to achieve full automation and easy operations with DropLab. Four ELISAs (the sample in triplicates and a negative control) can be run in parallel on the thermoformed disposable chip, which greatly improves the throughput and accuracy compared to those of other POCT immunodiagnostic devices. DropLab was validated by measuring two protein targets and one antibody target. The testing results showed that the limit of detection (LOD) of DropLab matched that of the conventional ELISA in a microwell plate. DropLab brings MDM one step closer to being a viable medical technology that is ready for real-world POCT applications.
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Affiliation(s)
- Xuyang Hu
- China-Singapore International Joint Research Institute, Guangzhou, China
- Guangzhou DropLab Scientific Co. Ltd., Guangzhou, China
| | - Xiangyu Gao
- China-Singapore International Joint Research Institute, Guangzhou, China
| | - Songlin Chen
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore
- DropLab Scientific (Singapore) Pvt. Ltd., Singapore, Singapore
| | - Jinhong Guo
- School of Sensing Science and Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yi Zhang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
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11
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Airaksinen KEJ, Aalto R, Hellman T, Vasankari T, Lahtinen A, Wittfooth S. Novel Troponin Fragmentation Assay to Discriminate Between Troponin Elevations in Acute Myocardial Infarction and End-Stage Renal Disease. Circulation 2022; 146:1408-1410. [PMID: 36315607 DOI: 10.1161/circulationaha.122.060845] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- K E Juhani Airaksinen
- Heart Center (K.E.J.A., T.V.), Turku University Hospital and University of Turku, Finland
| | - Rami Aalto
- Biotechnology Unit, Department of Life Technologies, University of Turku, Finland (R.A., A.L., S.W.)
| | - Tapio Hellman
- Kidney Center (T.H.), Turku University Hospital and University of Turku, Finland
| | - Tuija Vasankari
- Heart Center (K.E.J.A., T.V.), Turku University Hospital and University of Turku, Finland
| | - Akseli Lahtinen
- Biotechnology Unit, Department of Life Technologies, University of Turku, Finland (R.A., A.L., S.W.)
| | - Saara Wittfooth
- Biotechnology Unit, Department of Life Technologies, University of Turku, Finland (R.A., A.L., S.W.)
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12
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Chaulin AM. Metabolic Pathway of Cardiospecific Troponins: From Fundamental Aspects to Diagnostic Role (Comprehensive Review). Front Mol Biosci 2022; 9:841277. [PMID: 35517866 PMCID: PMC9062030 DOI: 10.3389/fmolb.2022.841277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/28/2022] [Indexed: 11/28/2022] Open
Abstract
Many molecules of the human body perform key regulatory functions and are widely used as targets for the development of therapeutic drugs or as specific diagnostic markers. These molecules undergo a significant metabolic pathway, during which they are influenced by a number of factors (biological characteristics, hormones, enzymes, etc.) that can affect molecular metabolism and, as a consequence, the serum concentration or activity of these molecules. Among the most important molecules in the field of cardiology are the molecules of cardiospecific troponins (Tns), which regulate the processes of myocardial contraction/relaxation and are used as markers for the early diagnosis of ischemic necrosis of cardiomyocytes (CMC) in myocardial infarction (MI). The diagnostic value and diagnostic capabilities of cardiospecific Tns have changed significantly after the advent of new (highly sensitive (HS)) detection methods. Thus, early diagnostic algorithms of MI were approved for clinical practice, thanks to which the possibility of rapid diagnosis and determination of optimal tactics for managing patients with MI was opened. Relatively recently, promising directions have also been opened for the use of cardiospecific Tns as prognostic markers both at the early stages of the development of cardiovascular diseases (CVD) (arterial hypertension (AH), heart failure (HF), coronary heart disease (CHD), etc.), and in non-ischemic extra-cardiac pathologies that can negatively affect CMC (for example, sepsis, chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), etc.). Recent studies have also shown that cardiospecific Tns are present not only in blood serum, but also in other biological fluids (urine, oral fluid, pericardial fluid, amniotic fluid). Thus, cardiospecific Tns have additional diagnostic capabilities. However, the fundamental aspects of the metabolic pathway of cardiospecific Tns are definitively unknown, in particular, specific mechanisms of release of Tns from CMC in non-ischemic extra-cardiac pathologies, mechanisms of circulation and elimination of Tns from the human body, mechanisms of transport of Tns to other biological fluids and factors that may affect these processes have not been established. In this comprehensive manuscript, all stages of the metabolic pathway are consistently and in detail considered, starting from release from CMC and ending with excretion (removal) from the human body. In addition, the possible diagnostic role of individual stages and mechanisms, influencing factors is analyzed and directions for further research in this area are noted.
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Affiliation(s)
- Aleksey M. Chaulin
- Department of Cardiology and Cardiovascular Surgery, Department of Clinical Chemistry, Samara State Medical University, Samara, Russia
- Samara Regional Clinical Cardiological Dispensary, Samara, Russia
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13
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The Importance of Cardiac Troponin Metabolism in the Laboratory Diagnosis of Myocardial Infarction (Comprehensive Review). BIOMED RESEARCH INTERNATIONAL 2022; 2022:6454467. [PMID: 35402607 PMCID: PMC8986381 DOI: 10.1155/2022/6454467] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 01/02/2023]
Abstract
The study of the metabolism of endogenous molecules is not only of great fundamental significance but also of high practical importance, since many molecules serve as drug targets and/or biomarkers for laboratory diagnostics of diseases. Thus, cardiac troponin molecules have long been used as the main biomarkers for confirmation of diagnosis of myocardial infarction, and with the introduction of high-sensitivity test methods, many of our ideas about metabolism of these cardiac markers have changed significantly. In clinical practice, there are opening new promising diagnostic capabilities of cardiac troponins, the understanding and justification of which are closely connected with the fundamental principles of the metabolism of these molecules. Our current knowledge about the metabolism of cardiac troponins is insufficient and extremely disconnected from various literary sources. Thus, many researchers do not sufficiently understand the potential importance of cardiac troponin metabolism in the laboratory diagnosis of myocardial infarction. The purpose of this comprehensive review is to systematize information about the metabolism of cardiac troponins and during the discussion to focus on the potential impact of cTns metabolism on the laboratory diagnosis of myocardial infarction. The format of this comprehensive review includes a sequential consideration and analysis of the stages of the metabolic pathway, starting from possible release mechanisms and ending with elimination mechanisms. This will allow doctors and researchers to understand the significant importance of cTns metabolism and its impact on the laboratory diagnosis of myocardial infarction.
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14
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Chaulin AM. Biology of Cardiac Troponins: Emphasis on Metabolism. BIOLOGY 2022; 11:429. [PMID: 35336802 PMCID: PMC8945489 DOI: 10.3390/biology11030429] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/28/2022] [Accepted: 03/07/2022] [Indexed: 02/07/2023]
Abstract
Understanding of the biology of endo- and exogenous molecules, in particular their metabolism, is not only of great theoretical importance, but also of high practical significance, since many molecules serve as drug targets or markers for the laboratory diagnostics of many human diseases. Thus, cardiac troponin (cTns) molecules have long been used as key markers for the confirmation of diagnosis of myocardial infarction (MI), and with the introduction of contemporary (high sensitivity) test methods, many of our concepts related to the biology of these cardiac markers have changed significantly. In current clinical practice, there are opening new promising diagnostic capabilities of cTns, the understanding and justification of which is closely connected with the theoretical principles of the metabolism of these molecules. However, today, the biology and metabolism of cTns have not been properly investigated; in particular, we do not know the precise mechanisms of release of these molecules from the myocardial cells (MCs) of healthy people and the mechanisms of circulation, and the elimination of cTns from the bloodstream. The main purpose of this manuscript is to systematize information about the biology of cTns, with an emphasis on the metabolism of cTns. The format of this paper, starting with the release of cTns in the blood and concluding with the metabolism/filtration of troponins, provides a comprehensive yet logically easy way for the readers to approach our current knowledge in the framework of understanding the basic mechanisms by which cTns are produced and processed. Conclusions. Based on the analysis of the current literature, the important role of biology and all stages of metabolism (release, circulation, removal) of cTns in laboratory diagnostics should be noted. It is necessary to continue studying the biology and metabolism of cTns, because this will improve the differential diagnosis of MI and i a new application of cTns immunoassays in current clinical practice.
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Affiliation(s)
- Aleksey M Chaulin
- Department of Histology and Embryology, Samara State Medical University, 89 Chapaevskaya Street, Samara Region, 443099 Samara, Russia
- Department of Cardiology and Cardiovascular Surgery, Samara State Medical University, 89 Chapaevskaya Street, Samara Region, 443099 Samara, Russia
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15
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Qiu J, Jiang P, Wang C, Chu Y, Zhang Y, Wang Y, Zhang M, Han L. Lys-AuNPs@MoS 2 Nanocomposite Self-Assembled Microfluidic Immunoassay Biochip for Ultrasensitive Detection of Multiplex Biomarkers for Cardiovascular Diseases. Anal Chem 2022; 94:4720-4728. [PMID: 35258919 DOI: 10.1021/acs.analchem.1c05061] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The progression of cardiovascular diseases is accompanied by myocardial injury and necrosis, heart failure, and inflammatory response. Accordingly, ultrasensitive and rapid detection of multiple biomarkers plays a vital role in clinical diagnosis and timely treatment. Here, we developed a novel Lys-AuNPs@MoS2 nanocomposite self-assembled microfluidic immunoassay biochip with digital signal output and applied it to the simultaneous detection of multiple serum biomarkers including inflammatory factors and cardiovascular biomarkers, PCT, CRP, IL6, cTnI, cTnT, and NT-BNP, with high throughput and sensitivity. The digital output signal was collected in the solid phase on the chip surface with two-dimensional distribution of targets. Lys-AuNPs@MoS2 nanocomposites self-assembled biochips could simultaneously detect all six biomarkers in 60 samples in 40 min with detection limit of a few to tens of pg/mL for all serum biomarkers. The microfluidic biochip based on Lys-AuNPs@MoS2 nanocomposites provides a promising method in applications for clinical diagnosis.
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Affiliation(s)
- Jiaoyan Qiu
- Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
| | - Peiqing Jiang
- Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Qingdao, Shandong 266035, China
| | - Chunhua Wang
- Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
| | - Yujin Chu
- Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
| | - Yu Zhang
- Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
| | - Yihe Wang
- Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
| | - Mei Zhang
- Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Qingdao, Shandong 266035, China
| | - Lin Han
- Institute of Marine Science and Technology, Shandong University, Qingdao, Shandong 266237, China
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16
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Chaulin A. Metabolic Pathway of Cardiac Troponins and Its Diagnostic Value. Vasc Health Risk Manag 2022. [DOI: 10.2147/vhrm.s335851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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17
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Regan B, O'Kennedy R, Collins D. Advances in point-of-care testing for cardiovascular diseases. Adv Clin Chem 2021; 104:1-70. [PMID: 34462053 DOI: 10.1016/bs.acc.2020.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Point-of-care testing (POCT) is a specific format of diagnostic testing that is conducted without accompanying infrastructure or sophisticated instrumentation. Traditionally, such rapid sample-to-answer assays provide inferior analytical performances to their laboratory counterparts when measuring cardiac biomarkers. Hence, their potentially broad applicability is somewhat bound by their inability to detect clinically relevant concentrations of cardiac troponin (cTn) in the early stages of myocardial injury. However, the continuous refinement of biorecognition elements, the optimization of detection techniques, and the fabrication of tailored fluid handling systems to manage the sensing process has stimulated the production of commercial assays that can support accelerated diagnostic pathways. This review will present the latest commercial POC assays and examine their impact on clinical decision-making. The individual elements that constitute POC assays will be explored, with an emphasis on aspects that contribute to economically feasible and highly sensitive assays. Furthermore, the prospect of POCT imparting a greater influence on early interventions for medium to high-risk individuals and the potential to re-shape the paradigm of cardiovascular risk assessments will be discussed.
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Affiliation(s)
- Brian Regan
- School of Biotechnology, Dublin City University, Dublin, Ireland.
| | - Richard O'Kennedy
- School of Biotechnology, Dublin City University, Dublin, Ireland; Research Complex, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - David Collins
- School of Biotechnology, Dublin City University, Dublin, Ireland
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18
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Hwang P, Schulz R, Kavsak P. Letter by Hwang et al Regarding Article, "Temporal Release of High-Sensitivity Cardiac Troponin T and I and Copeptin After Brief Induced Coronary Artery Balloon Occlusion in Humans". Circulation 2021; 144:e166-e167. [PMID: 34460322 DOI: 10.1161/circulationaha.121.055413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Damen SAJ, Cramer GE, Dieker HJ, Gehlmann H, Ophuis TJMO, Aengevaeren WRM, Fokkert M, Verheugt FWA, Suryapranata H, Wu AH, van Wijk XMR, Brouwer MA. Cardiac Troponin Composition Characterization after Non ST-Elevation Myocardial Infarction: Relation with Culprit Artery, Ischemic Time Window, and Severity of Injury. Clin Chem 2021; 67:227-236. [PMID: 33418572 DOI: 10.1093/clinchem/hvaa231] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 09/10/2020] [Indexed: 11/14/2022]
Abstract
BACKGROUND Troponin composition characterization has been implicated as a next step to differentiate among non-ST elevation myocardial infarction (NSTEMI) patients and improve distinction from other conditions with troponin release. We therefore studied coronary and peripheral troponin compositions in relation to clinical variables of NSTEMI patients. METHODS Samples were obtained from the great cardiac vein (GCV), coronary sinus (CS), and peripheral circulation of 45 patients with NSTEMI. We measured total cTnI concentrations, and assessed both complex cTnI (binary cTnIC + all ternary cTnTIC forms), and large-size cTnTIC (full-size and partially truncated cTnTIC). Troponin compositions were studied in relation to culprit vessel localization (left anterior descending artery [LAD] or non-LAD), ischemic time window, and peak CK-MB value. RESULTS Sampling occurred at a median of 25 hours after symptom onset. Of total peripheral cTnI, a median of 87[78-100]% consisted of complex cTnI; and 9[6-15]% was large-size cTnTIC. All concentrations (total, complex cTnI, and large-size cTnTIC) were significantly higher in the CS than in peripheral samples (P < 0.001). For LAD culprit patients, GCV concentrations were all significantly higher; in non-LAD culprit patients, CS concentrations were higher. Proportionally, more large-size cTnTIC was present in the earliest sampled patients and in those with the highest CK-MB peaks. CONCLUSIONS In coronary veins draining the infarct area, concentrations of both full-size and degraded troponin were higher than in the peripheral circulation. This finding, and the observed associations of troponin composition with the ischemic time window and the extent of sustained injury may contribute to future characterization of different disease states among NSTEMI patients.
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Affiliation(s)
- Sander A J Damen
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gilbert E Cramer
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hendrik-Jan Dieker
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Helmut Gehlmann
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ton J M Oude Ophuis
- Department of Cardiology, Canisius Wilhelmina Hospital, Nijmegen, The Netherlands
| | | | - Marion Fokkert
- Department of Clinical Chemistry, Isala Clinics, Zwolle, The Netherlands
| | - Freek W A Verheugt
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Harry Suryapranata
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alan H Wu
- Department of Clinical Chemistry, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, CA
| | - Xander M R van Wijk
- Department of Clinical Chemistry, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, CA
- Department of Pathology, The University of Chicago, Chicago, IL
| | - Marc A Brouwer
- Department of Cardiology, Radboud University Medical Center, Nijmegen, The Netherlands
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Katrukha IA, Katrukha AG. Myocardial Injury and the Release of Troponins I and T in the Blood of Patients. Clin Chem 2021; 67:124-130. [PMID: 33418589 DOI: 10.1093/clinchem/hvaa281] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 10/28/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Cardiac troponin I (cTnI) and cTnT are the established biomarkers of cardiomyocyte damage and the recommended biomarkers for the diagnosis of acute myocardial infarction (MI). High-sensitivity immunochemical diagnostic systems are able to measure the cTn concentrations in the blood of a majority of healthy people. At the same time, the concentration of cTn may be increased not only after MI but also because of other pathologies that might affect myocardium. This effect reduces the clinical specificity of cTn for MI and may complicate the diagnosis. CONTENT This review summarizes the existing information regarding the causes and mechanisms that lead to the increase of cTn concentration in blood and the forms of cTn that are present in circulation after MI or other types of myocardial injury. SUMMARY Different etiologies of disease associated with increases of cTn above the 99th percentile and various mechanisms of troponin release from myocardium could result in the appearance of different forms of cTn in blood and provide the first clinical evidence of injury. Additional research is needed for the careful characterization of cTn forms that are present in the blood in different clinical settings. That knowledge may lead to the development of immunochemical systems that would differentiate certain forms of troponins and possibly certain types of cardiac disease.
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Affiliation(s)
- Ivan A Katrukha
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, School of Biology, MV Lomonosov Moscow State University, Moscow, Russia
| | - Alexey G Katrukha
- HyTest Ltd., Turku, Finland
- Department of Biochemistry, School of Biology, MV Lomonosov Moscow State University, Moscow, Russia
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21
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Kavsak PA, Kittanakom S. Impact of Switching Sample Types for High-Sensitivity Cardiac Troponin I Assays in the 0/1 Hour Algorithms. Clin Chem 2021; 67:319-321. [PMID: 33221833 DOI: 10.1093/clinchem/hvaa191] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2020] [Indexed: 11/15/2022]
Affiliation(s)
| | - Saranya Kittanakom
- William Osler Health System, Brampton, ON, Canada
- University of Toronto, Toronto, ON, Canada
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22
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de Boer D, Streng AS, van Doorn WPTM, Vroemen WHM, Bekers O, Wodzig WKWH, Mingels AMA. Cardiac Troponin T: The Impact of Posttranslational Modifications on Analytical Immunoreactivity in Blood up to the Excretion in Urine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1306:41-59. [PMID: 33959905 DOI: 10.1007/978-3-030-63908-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cardiac troponin T (cTnT) is a sensitive and specific biomarker for detecting cardiac muscle injury. Its concentration in blood can be significantly elevated outside the normal reference range under several pathophysiological conditions. The classical analytical method in routine clinical analysis to detect cTnT in serum or plasma is a single commercial immunoassay, which is designed to quantify the intact cTnT molecule. The targeted epitopes are located in the central region of the cTnT molecule. However, in blood cTnT exists in different biomolecular complexes and proteoforms: bound (to cardiac troponin subunits or to immunoglobulins) or unbound (as intact protein or as proteolytic proteoforms). While proteolysis is a principal posttranslational modification (PTM), other confirmed PTMs of the proteoforms include N-terminal initiator methionine removal, N-acetylation, O-phosphorylation, O-(N-acetyl)-glucosaminylation, N(ɛ)-(carboxymethyl)lysine modification and citrullination. The immunoassay probably detects several of those cTnT biomolecular complexes and proteoforms, as long as they have the centrally targeted epitopes in common. While analytical cTnT immunoreactivity has been studied predominantly in blood, it can also be detected in urine, although it is unclear in which proteoform cTnT immunoreactivity is present in urine. This review presents an overview of the current knowledge on the pathophysiological lifecycle of cTnT. It provides insight into the impact of PTMs, not only on the analytical immunoreactivity, but also on the excretion of cTnT in urine as one of the waste routes in that lifecycle. Accordingly, and after isolating the proteoforms from urine of patients suffering from proteinuria and acute myocardial infarction, the structures of some possible cTnT proteoforms are reconstructed using mass spectrometry and presented.
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Affiliation(s)
- Douwe de Boer
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands.
- NUTRIM, School of Nutrition and Translational Research in Metabolism, Medicine and Life Sciences (FHML) of Maastricht University (UM), Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Alexander S Streng
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - William P T M van Doorn
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Wim H M Vroemen
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Otto Bekers
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM, School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences (FHML) of Maastricht University (UM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Will K W H Wodzig
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
- NUTRIM, School of Nutrition and Translational Research in Metabolism, Medicine and Life Sciences (FHML) of Maastricht University (UM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Alma M A Mingels
- Unit of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
- CARIM, School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences (FHML) of Maastricht University (UM), Maastricht University Medical Center, Maastricht, The Netherlands
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Harley K, Bissonnette S, Inzitari R, Schulz K, Apple FS, Kavsak PA, Gunsolus IL. Independent and combined effects of biotin and hemolysis on high-sensitivity cardiac troponin assays. Clin Chem Lab Med 2021; 59:1431-1443. [PMID: 33761581 DOI: 10.1515/cclm-2021-0124] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/16/2021] [Indexed: 12/27/2022]
Abstract
OBJECTIVES This study compared the independent and combined effects of hemolysis and biotin on cardiac troponin measurements across nine high-sensitivity cardiac troponin (hs-cTn) assays. METHODS Parallel cTn measurements were made in pooled lithium heparin plasma spiked with hemolysate and/or biotin using nine hs-cTn assays: Abbott Alinity, Abbott ARCHITECT i2000, Beckman Access 2, Ortho VITROS XT 7600, Siemens Atellica, Siemens Centaur, Siemens Dimension EXL cTnI, and two Roche Cobas e 411 Elecsys Troponin T-hs cTnT assays (outside US versions, with and without increased biotin tolerance). Absolute and percent cTn recovery relative to two baseline concentrations were determined in spiked samples and compared to manufacturer's claims. RESULTS All assays except the Ortho VITROS XT 7600 showed hemolysis and biotin interference thresholds equivalent to or greater than manufacturer's claims. While imprecision confounded analysis of Ortho VITROS XT 7600 data, evidence of biotin interference was lacking. Increasing biotin concentration led to decreasing cTn recovery in three assays, specifically both Roche Cobas e 411 Elecsys Troponin T-hs assays and the Siemens Dimension EXL. While one of the Roche assays was the most susceptible to biotin among the nine studied, a new version showed reduced biotin interference by approximately 100-fold compared to its predecessor. Increasing hemolysis also generally led to decreasing cTn recovery for susceptible assays, specifically the Beckman Access 2, Ortho VITROS XT 7600, and both Roche Cobas e 411 Elecsys assays. Equivalent biotin and hemolysis interference thresholds were observed at the two cTn concentrations considered for all but two assays (Beckman Access 2 and Ortho VITROS XT 7600). When biotin and hemolysis were present in combination, biotin interference thresholds decreased with increasing hemolysis for two susceptible assays (Roche Cobas e 411 Elecsys and Siemens Dimension EXL). CONCLUSIONS Both Roche Cobas e 411 Elecsys as well as Ortho VITROS XT assays were susceptible to interference from in vitro hemolysis at levels routinely encountered in clinical laboratory samples (0-3 g/L free hemoglobin), leading to falsely low cTn recovery up to 3 ng/L or 13%. While most assays are not susceptible to biotin at levels expected with over-the-counter supplementation, severely reduced cTn recovery is possible at biotin levels of 10-2000 ng/mL (41-8,180 nmol/L) for some assays. Due to potential additive effects, analytical interferences should not be considered in isolation.
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Affiliation(s)
| | - Sarah Bissonnette
- Department of Pathology, Marshfield Clinic Health System, Marshfield, WI, USA
| | - Rosanna Inzitari
- University College Dublin School of Medicine, Clinical Research Centre, Dublin, Ireland
| | - Karen Schulz
- Hennepin Healthcare Research Institute, Hennepin County Medical Center, Minneapolis, MN, USA
| | - Fred S Apple
- Departments of Laboratory Medicine & Pathology, Hennepin Healthcare/Hennepin County Medical Center, Hennepin Healthcare Research Institute and University of Minnesota, Minneapolis, MN, USA
| | - Peter A Kavsak
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Ian L Gunsolus
- Department of Pathology, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI, 53226, USA
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Casas-Tintó S, Ferrús A. The haplolethality paradox of the wupA gene in Drosophila. PLoS Genet 2021; 17:e1009108. [PMID: 33739971 PMCID: PMC8011728 DOI: 10.1371/journal.pgen.1009108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 03/31/2021] [Accepted: 02/15/2021] [Indexed: 11/18/2022] Open
Abstract
Haplolethals (HL) are regions of diploid genomes that in one dose are fatal for the organism. Their biological meaning is obscure because heterozygous loss-of-function mutations result in dominant lethality (DL) and, consequently, should be under strong negative selection. We report an in depth study of the HL associated to the gene wings up A (wupA). It encodes 13 transcripts (A-M) that yield 11 protein isoforms (A-K) of Troponin I (TnI). They are functionally diverse in their control of muscle contraction, cell polarity and cell proliferation. Isoform K transfers to the nucleus where it increases transcription of the cell proliferation related genes CDK2, CDK4, Rap and Rab5. The nuclear translocation of isoform K is prevented by the co-expression of A or B isoforms, which illustrates isoform interactions. The corresponding DL mutations are, either DNA rearrangements clustered towards the gene 3’ end, thus affecting the genomic organization of all transcripts, or CRISPR-induced mutations in one of the two ATG sites which eliminate a subset of wupA products. The joint elimination of isoforms C, F, G and H, however, do not cause DL phenotypes. Genetically driven expression of single isoforms rescue neither DL nor any of the mutants known in the gene, suggesting that normal function requires properly regulated expression of specific combinations, rather than single, TnI isoforms. We conclude that the wupA associated HL results from the combined haploinsufficiency of a large set of TnI isoforms. The qualitative and quantitative normal expression of which, requires the chromosomal integrity of the wupA genomic region. Since all fly TnI isoforms are encoded in the same gene, its HL condition becomes unavoidable. These wupA features are comparable to those of dpp, the only other HL studied to some extent, and reveal a scenario of strict dosage dependence with implications for gene expression regulation and splitting. Most species contain two copies of their genetic endowment, each received from each progenitor. If one of the duplicated genes is non-functional, the remaining copy may supply enough product as to cover the requirements for normal function or, alternatively, may reflect the insufficiency through a visible phenotype. In rare occasions, however, having one copy is so deleterious that causes lethality. These so called “haplolethal regions”, exist across species and represent an evolutionary paradox since they should have been subject to intense negative selection. The inherent difficulties to study haplolethals have precluded their study so far. Here, we analyzed the case of one of the five haplolethal regions of Drosophila, the one associated to the Troponin I encoding gene wupA, by measuring the transcriptional effects of mutations and chromosomal rearrangements affecting this gene. The data show that this haplolethality results from the combined insufficiency of a large number of Troponin I isoforms, which are functionally specialized, show interference and require the integrity of the native chromatin structure for their quantitatively regulated expression. These features unveil novel aspects of gene expression and, possibly, on evolutionary gene splitting. Also, haplolethals underscore the biological significance of protein dosage, in particular for functionally related products.
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Affiliation(s)
- Sergio Casas-Tintó
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Alberto Ferrús
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid, Spain
- * E-mail:
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25
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Huang B, Wu J, Chen H, Zhang L, Zhou X, Wu Q, Li T, Wang Y, Xia P, Dai Y, Kai G, Liu P, Pei H. Establishment and Application of a Dual-Labeling Time-Resolved Fluorescence Immunoassay Method for Simultaneous Detection of the Troponin I-C Complex and Full-Size-Troponin I. Front Cardiovasc Med 2021; 7:596051. [PMID: 33521060 PMCID: PMC7840586 DOI: 10.3389/fcvm.2020.596051] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/16/2020] [Indexed: 01/10/2023] Open
Abstract
Background: The measurement of cardiac troponin I (cTnI) is widely used in the diagnosis of acute myocardial infarction (AMI). Although existing cTnI detection methods measure total cTnI, the significance of undegraded full-size-cTnI levels is still not well-understood. In this study, we have established a novel dual-labeling time-resolved fluorescence immunoassay (TRFIA) technique that simultaneously detects the cTnI-C complex and full-size-cTnI, allowing us to explore the clinical value of full-size-cTnI determination. Methods: An antibody against the 23–43 amino acid region of cTnI protected by endogenous cTnC is coupled to magnetic beads to provide a solid-phase antibody for capturing all cTnI. An antibody against cTnC in the cTnI-C complex labeled with Eu3+ was used to detect the cTnI-C complex, and an antibody labeled with Sm3+ near the C-terminal 190–203 amino acids of cTnI was used to detect full-size-cTnI. Through dual-labeling TRFIA, cTnI-C complex, full-size-cTnI, and the full-size-cTnI/cTnI-C ratio can be detected simultaneously. The dual-labeling TRFIA technique was used to analyze serum samples collected at different times during treatment and compare their full-size-cTnI/cTnI-C ratios. Results: The sensitivity for the cTnI-C-TRFIA complex was 0.02 ng/mL, the measurement range was 0.02–40 ng/mL, the average intra-batch coefficient of variation (CV) was 4.35%, and the inter-average CV was 6.23%. The correlation coefficient between cTnI-C-TRFIA and commercial cTnI-CLIA methods was R2 = 0.8887. The sensitivity for full-size-cTnI-TRFIA was 0.04 ng/mL, the measurement range was 0.04–40 ng/mL, the average intra-batch CV was 4.95%, and the average inter-batch CV was 7.79%. The correlation coefficient between full-size-cTnI-TRFIA and commercial cTnI-CLIA methods was R2 = 0.7247. Conclusions: Dual-labeling full-size-cTnI/cTnI-C-TRFIA analysis is helpful for determining the length of time of chest pain before admission and the degree of continuous release of cTnI in the myocardium. Thus, it is more for early prognosis than just detecting cTnI.
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Affiliation(s)
- Biao Huang
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Jian Wu
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Department of Laboratory Medicine, The First People's Hospital of Yancheng City, Yancheng, China
| | - Hao Chen
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Li Zhang
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Xiumei Zhou
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Qingqing Wu
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Ting Li
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yigang Wang
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Penguo Xia
- Immounoassay Laboratory, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
| | - Yaping Dai
- Clinical Lab, Wuxi No.5 People's Hospital, Wuxi, China
| | - Guoyin Kai
- Chinese Medicine Resources Teaching and Research Laboratory, College of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, China
| | - Pengfei Liu
- Department of Gastroenterology, The Jiangyin Clinical College of Xuzhou Medical University, Jiangyin, China
| | - Hao Pei
- Clinical Lab, Wuxi No.5 People's Hospital, Wuxi, China
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Development of a Novel Sensor System Based on Magnetic Microspheres to Detect Cardiac Troponin T. INT J POLYM SCI 2020. [DOI: 10.1155/2020/8855550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acute myocardial infarction (AMI) causes irreversible injury to cardiomyocytes in a short time and may result in various complications, severely threatening patient safety. Therefore, it is necessary to predict the possibility of AMI in the prophase. Prognostic detection of biomarkers that specifically reflect myocardial damage in a patient’s blood has become an essential mediating measure to prevent the serious occurrence of AMI. The present study is aimed at exploring a novel sensing system with high specificity and precision based on magnetic microspheres developed to detect cardiac troponin T (cTnT), which is the most specific diagnostic marker for AMI in cardiovascular diseases. Naive human cTnT protein in serum samples and antigens on functional magnetic microspheres will competitively bind with limited specific antibodies. After rapid removal of heterogeneous elements in the sera using a magnetic separator, fluorescein isothiocyanate-labeled immunoglobulin G is added to react with specific antibodies on the magnetic microspheres. Then, a flow cytometer is used to collect signals of different fluorescence intensities. The results show that the method is characterized by economy, high accuracy, and novelty. It can be used for the detection of cTnT in blood at 1.7–106.1 ng/mL, with a detection limit of 0.5 ng/mL. Thus, the proposed sensor improves the accuracy and efficiency of diagnosis before clinical deterioration of AMI.
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Apple FS, Wu AHB, Sandoval Y, Sexter A, Love SA, Myers G, Schulz K, Duh SH, Christenson RH. Sex-Specific 99th Percentile Upper Reference Limits for High Sensitivity Cardiac Troponin Assays Derived Using a Universal Sample Bank. Clin Chem 2020; 66:434-444. [PMID: 32109298 DOI: 10.1093/clinchem/hvz029] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 10/23/2019] [Indexed: 01/29/2023]
Abstract
BACKGROUND How to select healthy reference subjects in deriving 99th percentiles for cardiac troponin assays still needs to be clarified. To assist with global implementation of high sensitivity (hs)-cardiac troponin (cTn) I and hs-cTnT assays in clinical practice, we determined overall and sex-specific 99th percentiles in 9 hs-cTnI and 3 hs-cTnT assays using a universal sample bank (USB). METHODS The Universal Sample Bank (USB) comprised healthy subjects, 426 men and 417 women, screened using a health questionnaire. Hemoglobin A1c (>URL 6.5%), NT-proBNP (>URL 125 ng/L) and eGFR (<60 mL/min), were used as surrogate biomarker exclusion criteria along with statin use. 99th percentiles were determined by nonparametric, Harrell--Davis bootstrap, and robust methods. RESULTS Subjects were ages 19 to 91 years, Caucasian 58%, African American 27%, Pacific Islander/Asian 11%, other 4%, Hispanic 8%, and non-Hispanic 92%. The overall and sex-specific 99th percentiles for all assays, before and after exclusions (n = 694), were influenced by the statistical method used, with substantial differences noted between and within both hs-cTnI and hs-cTnT assays. Men had higher 99th percentiles (ng/L) than women. The Roche cTnT and Beckman and Abbott cTnI assays (after exclusions) did not measure cTn values at ≥ the limit of detection in ≥50% women. CONCLUSIONS Our findings have important clinical implications in that sex-specific 99th percentiles varied according to the statistical method and hs-cTn assay used, not all assays provided a high enough percentage of measurable concentrations in women to qualify as a hs-assay, and the surrogate exclusion criteria used to define normality tended to lower the 99th percentiles.
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Affiliation(s)
- Fred S Apple
- Department of Laboratory Medicine & Pathology, Hennepin Healthcare/Hennepin Country Medical Center, Hennepin Healthcare Research Institute and University of Minnesota, Minneapolis, MN
| | - Alan H B Wu
- Department of Laboratory Medicine, University of California, San Francisco, CA
| | - Yader Sandoval
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN
| | - Anne Sexter
- Chronic Disease Research Group, Hennepin Healthcare Research Institute, Minneapolis, MN
| | - Sara A Love
- Department of Laboratory Medicine & Pathology, Hennepin Healthcare/Hennepin Country Medical Center, Hennepin Healthcare Research Institute and University of Minnesota, Minneapolis, MN
| | | | - Karen Schulz
- Hennepin Healthcare Research Institute, Hennepin County Medical Center, Minneapolis, MN
| | - Show-Hong Duh
- Department of Pathology, University of Maryland Medical Center, Baltimore, MD
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Lam L, Heron C, Aspin L, Ha L, Kyle CV. Change in troponin concentrations in patients with macrotroponin: An in vitro mixing study. Clin Biochem 2020; 85:43-48. [PMID: 32861681 DOI: 10.1016/j.clinbiochem.2020.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/06/2020] [Accepted: 08/25/2020] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Macrotroponin is a complex formed between endogenous cardiac troponin autoantibodies (cTnAABs) and circulating cardiac troponin (cTn). The potential effect of macrotroponin on current high sensitivity cTn assays has not been fully explored but has recently been identified as a major cause of discrepancy in cTn results between assays. In this study we investigated the effects of mixing troponin (cTn) standards to specimens with and without macrotroponin. METHOD Macrotroponin was identified in specimens by a recovery of cTnI < 40% following protein A immunoglobulin depletion. Troponin standards containing cTn-IC and cTn-TIC complexes were mixed with serum samples, with (n = 20) and without (n = 10) the presence of macrotroponin. Specimens were tested for cTn before and after mixing by three commercially available high sensitivity cTn assays. Gel filtration chromatography was carried out on five specimens with macrotroponin and each fraction was analzyed by multiple cTn assays. FINDINGS Following mixing with cTn-TIC standard, all specimens with macrotroponin had a markedly reduced absolute increase in cTnI, indicating negative analytical interference due to macrotroponin. Following mixing with the cTn-IC standard, specimens with macrotroponin demonstrated highly variable changes in cTnI, suggesting significant heterogeneity in macrotroponin complex reactivity between individuals. When the ratio of change, calculated by dividing the absolute change between two cTn assays, was compared between specimens with and without macrotroponin, significant differences were observed (p < 0.001). These findings were supported by variable migration of peak cTn activity on gel filtration chromatography. CONCLUSION Macrotroponin leads to assay dependent analytical interference affecting current high sensitivity troponin I assays. Furthermore, endogenously occurring cTnAABs are conformationally specific and the analytical effects vary between assays and individuals.
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Affiliation(s)
- Leo Lam
- Department of Chemical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand; Department of Biochemistry, Middlemore Hospital Laboratory, Auckland, New Zealand
| | - Campbell Heron
- Department of Chemical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Lisa Aspin
- Department of Biochemistry, Labtests, Auckland, New Zealand
| | - Leah Ha
- Department of Chemical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand; Department of Biochemistry, Middlemore Hospital Laboratory, Auckland, New Zealand
| | - Campbell V Kyle
- Department of Chemical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand; Department of Biochemistry, Labtests, Auckland, New Zealand.
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Aakre KM, Saeed N, Wu AHB, Kavsak PA. Analytical performance of cardiac troponin assays - Current status and future needs. Clin Chim Acta 2020; 509:149-155. [PMID: 32540128 DOI: 10.1016/j.cca.2020.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/03/2020] [Accepted: 06/11/2020] [Indexed: 02/06/2023]
Abstract
Concurrent with the introduction of cardiac troponin measurements into the diagnostic definition of myocardial infarction (MI), clinicians and laboratory professionals signaled a clear clinical need for improved analytical quality. This was an important precipitant for developing high-sensitivity cardiac troponin (hs-cTn) assays, currently used in rapid algorithms guiding investigations of patients presenting to the emergency department with possible MI. The hs-cTn assays were also important for the detection and monitoring of low-grade chronic myocardial injury, a condition that has been linked to increased long-term risk of cardiovascular morbidity and mortality. This review summarizes the general recommendations for defining analytical performance specifications while providing relevant clinical situations related to analytical performance. Importantly, outcome studies suggest analytical quality performance for hs-cTn is sufficient for early discharge of patients investigated for possible MI. However, bias due to change in calibrators or reagents may significantly affect the percentage of patients discharged. Biological variation data is suitable for defining performance specifications when hs-cTn measurements are used for diagnosing and monitoring chronic myocardial injury. Further improvement in analytical performance for hs-cTn testing may result in even faster decision making in the emergency setting; while also identifying those with chronic injury at risk for an adverse cardiac event.
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Affiliation(s)
- Kristin M Aakre
- Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.
| | - Nasir Saeed
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Alan H B Wu
- University of California, San Francisco, CA, United States
| | - Peter A Kavsak
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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Zhang C, Gan X, Liang R, Jian J. Exosomes Derived From Epigallocatechin Gallate-Treated Cardiomyocytes Attenuated Acute Myocardial Infarction by Modulating MicroRNA-30a. Front Pharmacol 2020; 11:126. [PMID: 32161548 PMCID: PMC7054242 DOI: 10.3389/fphar.2020.00126] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 01/29/2020] [Indexed: 12/15/2022] Open
Abstract
Background Ischemia-derived exosomes can restrict excessive autophagy by transferring microRNA-30a (miR30a) to cells. Reports have confirmed that epigallocatechin gallate (EGCG) alleviates acute myocardial infarction (AMI) by regulating autophagy; however, research evaluating the communication with cardiomyocytes and exosomes is lacking. This study aimed to explore whether exosomes derived from EGCG-treated cardiomyocytes mitigated AMI by adjusting miR30a to inactivate apoptosis and autophagy. Methods Exosomes were extracted from cardiomyocytes, cultured either in control or AMI condition, with or without EGCG pretreatment. The exosome characteristics were analyzed by nanoparticle tracking analyses and transmission electron microscopy. The change in miR30a in cells and exosomes was demonstrated by qRT-PCR. H9c2 or stable miR30a knockdown (miR30aKD) cell lines were incubated with exosomes derived from EGCG-treated cardiomyocytes in vitro or in vivo. The effect of EGCG and exosomes on I/R-induced cardiomyocyte apoptosis and autophagy was assessed. Results EGCG improved the activity of cardiomyocytes, and increased average diameter, concentration, miR30a mRNA level, and specific protein expression in AMI-derived exosomes produced by cardiomyocytes. Moreover, the coincubation of AMI cells with EGCG or exosomes derived from EGCG-treated cardiomyocytes attenuated cardiomyocyte apoptosis and autophagy. Conclusions The findings showed that EGCG upregulates miR30a, which was efficiently transferred via exosomes between cardiomyocytes, thereby contributing to the suppression of apoptosis and autophagy. By focusing on the cardiomyocyte microenvironment, we identified a new target of EGCG alleviating AMI by regulating apoptosis and autophagy.
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Affiliation(s)
- Chan Zhang
- Department of Pharmacology, Xiangya Hospital, Central South University, Changsha, China
| | - Xiaowen Gan
- Department of Pharmacology, Guilin Medical University, Guilin, China
| | - Ronggan Liang
- Department of Pharmacology, Guilin Medical University, Guilin, China
| | - Jie Jian
- Department of Pharmacology, Guilin Medical University, Guilin, China
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Cardiac troponin I is present in plasma of type 1 myocardial infarction patients and patients with troponin I elevations due to other etiologies as complex with little free I. Clin Biochem 2019; 73:35-43. [DOI: 10.1016/j.clinbiochem.2019.06.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 11/23/2022]
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Hwang P, Mingels A, Kavsak PA. High-sensitivity cardiac troponin testing during and after ACS: Complexed or not? Clin Biochem 2019; 73:32-34. [PMID: 31361993 DOI: 10.1016/j.clinbiochem.2019.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 07/24/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Peter Hwang
- Departments of Medicine and Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Alma Mingels
- Department of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Peter A Kavsak
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.
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Damen SAJ, Vroemen WHM, Brouwer MA, Mezger STP, Suryapranata H, van Royen N, Bekers O, Meex SJR, Wodzig WKWH, Verheugt FWA, de Boer D, Cramer GE, Mingels AMA. Multi-Site Coronary Vein Sampling Study on Cardiac Troponin T Degradation in Non-ST-Segment-Elevation Myocardial Infarction: Toward a More Specific Cardiac Troponin T Assay. J Am Heart Assoc 2019; 8:e012602. [PMID: 31269858 PMCID: PMC6662151 DOI: 10.1161/jaha.119.012602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/17/2019] [Indexed: 01/24/2023]
Abstract
Background Cardiac troponin T ( cTnT ) is seen in many other conditions besides myocardial infarction, and recent studies demonstrated distinct forms of cTnT . At present, the in vivo formation of these different cTnT forms is incompletely understood. We therefore performed a study on the composition of cTnT during the course of myocardial infarction, including coronary venous system sampling, close to its site of release. Methods and Results Baseline samples were obtained from multiple coronary venous system locations, and a peripheral artery and vein in 71 non- ST -segment-elevation myocardial infarction patients. Additionally, peripheral blood was drawn at 6- and 12-hours postcatheterization. cTnT concentrations were measured using the high-sensitivity- cTnT immunoassay. The cTnT composition was determined via gel filtration chromatography and Western blotting in an early and late presenting patient. High-sensitivity - cTnT concentrations were 28% higher in the coronary venous system than peripherally (n=71, P<0.001). Coronary venous system samples demonstrated cT n T-I-C complex, free intact cTnT , and 29 kD a and 15 to 18 kD a cTnT fragments, all in higher concentrations than in simultaneously obtained peripheral samples. While cT n T-I-C complex proportionally decreased, and disappeared over time, 15 to 18 kD a cTnT fragments increased. Moreover, cT n T-I-C complex was more prominent in the early than in the late presenting patient. Conclusions This explorative study in non- ST -segment-elevation myocardial infarction shows that cTnT is released from cardiomyocytes as a combination of cT n T-I-C complex, free intact cTnT , and multiple cTnT fragments indicating intracellular cTnT degradation. Over time, the cT n T-I-C complex disappeared because of in vivo degradation. These insights might serve as a stepping stone toward a high-sensitivity- cTnT immunoassay more specific for myocardial infarction.
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Affiliation(s)
- Sander A. J. Damen
- Department of CardiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Wim H. M. Vroemen
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Marc A. Brouwer
- Department of CardiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Stephanie T. P. Mezger
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Harry Suryapranata
- Department of CardiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Niels van Royen
- Department of CardiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Otto Bekers
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Steven J. R. Meex
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Will K. W. H. Wodzig
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - Freek W. A. Verheugt
- Department of CardiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Douwe de Boer
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
| | - G. Etienne Cramer
- Department of CardiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Alma M. A. Mingels
- Central Diagnostic LaboratoryMaastricht University Medical CenterMaastrichtThe Netherlands
- CARIM School for Cardiovascular DiseasesMaastricht UniversityMaastrichtThe Netherlands
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