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Lam L, Ha L, Heron C, Chiu W, Kyle C. Identification of macrotroponin T: findings from a case report and non-reproducible troponin T results. Clin Chem Lab Med 2021; 59:1972-1980. [PMID: 34496163 DOI: 10.1515/cclm-2021-0626] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/24/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Macrotroponin is due to cardiac troponin (cTn) binding to endogenous cTn autoantibodies. While previous studies showed a high incidence of macrotroponin affecting cTnI assays, reports of macrotroponin T, particularly without cTnI reactivity, have been rare. Although the clinical significance of macrotroponin is not fully understood, macroenzymes and complexes are recognised to cause confusion in interpretation of laboratory results. The potential for adverse clinical consequences due to misinterpretation of affected results is very high. METHODS We describe four cases of macrotroponin T with persistently low high sensitivity cTnT (hs-cTnT) by the 9 min compared to the 18 min variant of the assay. Three cases were serendipitously identified due to the use of a lot number of Roche hs-cTnT affected by non-reproducible results, necessitating measurement of cTnT in duplicate. We identified and characterised these macrotroponin specimens by immunoglobulin depletion (Protein A and PEG precipitation), mixing studies with EDTA and recombinant cTnT. RESULTS In cases of macro-cTnT, a lower result occurred on the hs-cTnT using the 9 min compared to 18 min variant assay (ratio of 9-18 min hs-cTnT <0.80). Mixing studies with recombinant cTnT or EDTA demonstrated a difference in recovery vs. controls. One of these patients demonstrated a high molecular weight complex for cTnI and cTnT demonstrating a macrocomplex involving both cTn. This patient demonstrated a rise and fall in cTn when measured by several commercial assays consistent with genuine acute cardiac injury. CONCLUSIONS We identified several cases of macro-cTnT and described associated clinical and biochemical features.
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Affiliation(s)
- Leo Lam
- Department of Chemical Pathology, LabPLUS, Auckland City Hospital, Auckland, New Zealand.,Biochemistry Department, Middlemore Hospital Laboratories, Middlemore Hospital, Auckland, New Zealand
| | - Leah Ha
- Department of Chemical Pathology, LabPLUS, Auckland City Hospital, Auckland, New Zealand.,Biochemistry Department, Middlemore Hospital Laboratories, Middlemore Hospital, Auckland, New Zealand
| | - Campbell Heron
- Department of Chemical Pathology, LabPLUS, Auckland City Hospital, Auckland, New Zealand
| | - Weldon Chiu
- Department of Chemical Pathology, LabPLUS, Auckland City Hospital, Auckland, New Zealand.,Biochemistry Department, Middlemore Hospital Laboratories, Middlemore Hospital, Auckland, New Zealand
| | - Campbell Kyle
- Department of Chemical Pathology, LabPLUS, Auckland City Hospital, Auckland, New Zealand.,Department of Biochemistry, LabTests, Auckland, New Zealand
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2
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Lam L, Ha L, Gladding P, Tse R, Kyle C. Effect of macrotroponin on the utility of cardiac troponin I as a prognostic biomarker for long term total and cardiovascular disease mortality. Pathology 2021; 53:860-866. [PMID: 34272050 DOI: 10.1016/j.pathol.2021.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 03/29/2021] [Accepted: 04/05/2021] [Indexed: 01/01/2023]
Abstract
Macrotroponin is a complex formed between endogenous cardiac troponin autoantibodies and circulating cardiac troponin (cTn). It is a recognised cause of discrepancy between current high sensitivity troponin (hs-cTn) assays; and immunoglobulin-bound (macrotroponin) and unbound cTn can coexist in varying proportions in the acute setting. Increasingly it is considered when laboratory cTn results do not match a patient's clinical picture. However, despite the better understanding of macrotroponin as an analytical interference, its clinical significance remains unclear. The aim of this study was to determine the potential impact of macrotroponin on the use of cTn as a long-term prognostic marker. We repeated cTnI testing after polyethylene glycol (PEG) precipitation on consecutive participants (n=159) with a first elevated cTn above 0.2 μg/L during their hospital admission episode. Because this paper is looking at outcomes in years, the initial data were generated at a time when non-hs-cTn assays were in use. We divided the cohort into two groups based on an exploratory PEG recovery cut-off of <34.6% to indicate the presence of possible macrotroponin and compared the overall and cardiovascular related mortality. The median follow-up time for the overall cohort was 8.35 years (8.32-8.40 interquartile range) with no difference between the two groups. The overall median survival was 8.1 years. Our findings indicate a hazard ratio of 0.54 (0.32-0.91 95% CI) for all-cause mortality and 0.48 (0.24-0.95) for cardiovascular mortality in patients with possible macrotroponin compared to those patients with troponin elevation without evidence of macrotroponin, after adjustment for common cardiovascular disease risk factors. Furthermore, an association was observed between PEG% recovery and all-cause mortality (p<0.05). This study showed that patients with macrotroponin have comparatively favourable long-term all-cause and cardiovascular mortality in a cohort of patients with elevated troponin. We illustrate the importance of recognising cTn results as being a summation of heterogeneous components, including those bound to antibodies, and the potential role of macrotroponin to further improve our interpretation and use of cTn as a biomarker.
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Affiliation(s)
- Leo Lam
- Department of Chemical Pathology, Auckland City Hospital, Auckland, New Zealand; Department of Biochemistry, Middlemore Hospital Laboratories, Auckland, New Zealand
| | - Leah Ha
- Department of Chemical Pathology, Auckland City Hospital, Auckland, New Zealand; Department of Biochemistry, Middlemore Hospital Laboratories, Auckland, New Zealand
| | - Patrick Gladding
- Department of Cardiology, North Shore Hospital, Auckland, New Zealand
| | - Rexson Tse
- Department of Forensic Pathology, Auckland City Hospital, Auckland, New Zealand
| | - Campbell Kyle
- Department of Chemical Pathology, Auckland City Hospital, Auckland, New Zealand; Department of Biochemistry, Labtests, Auckland, New Zealand.
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3
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Chaulin A. Cardiac Troponins: Contemporary Biological Data and New Methods of Determination. Vasc Health Risk Manag 2021; 17:299-316. [PMID: 34113117 PMCID: PMC8184290 DOI: 10.2147/vhrm.s300002] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 04/21/2021] [Indexed: 12/19/2022] Open
Abstract
Laboratory diagnosis plays one of the key roles in the diagnosis of many diseases, including cardiovascular diseases (CVD). The methods underlying the in vitro study of many CVD biomarkers, including cardiac troponins (cTnI and cTnT), are imperfect and are continually being improved to enhance their analytical performance, with sensitivity and specificity being the most important. Recently developed improved cTnI and cTnT detection methods, referred to as highly sensitive methods (hs-cTnI, hs-cTnT), have changed many of our ideas about the biology of cardiac troponins and opened up a number of additional diagnostic capabilities for practical healthcare. This article systematizes some relevant data on the biology of cardiac troponins as well as on methods for determining cTnI and cTnT with an analysis of the diagnostic value of their analytical characteristics (limit of blank, limit of detection, 99th percentile, coefficient of variation, and others). Data on extracardiac expression of cTnI and cTnT, mechanisms of formation and potential clinical significance of gender, age, and circadian characteristics of hs-cTnI and hs-cTnT content in serum are discussed. Considerable attention is paid to the discussion of new diagnostic capabilities of hs-cTnI, hs-cTnT, including consideration of promising possibilities for their study in biological fluids that can be obtained by non-invasive methods. Also, some possibilities of using hs-cTnI and hs-cTnT as prognostic laboratory biomarkers in healthy people (for example, to assess the risk of developing CVD) and in patients suffering from a number of pathological conditions that cause damage to cardiomyocytes are examined, and the potential mechanisms underlying the increase in hs-cTnI and hs-cTnT are discussed.
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Affiliation(s)
- Aleksey Chaulin
- Department of Cardiology and Cardiovascular Surgery, Samara State Medical University, Samara, 443099, Russia.,Department of Histology and Embryology, Samara State Medical University, Samara, 443099, Russia
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4
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Yan M, Wang J, Wang S, Zhang Y, Liu L, Zhao H. Expression Levels of MicroRNA-146b and Anti-Cardiac Troponin I in Serum of Children with Viral Myocarditis and Their Clinical Significance. IRANIAN JOURNAL OF PUBLIC HEALTH 2021; 50:510-519. [PMID: 34178798 PMCID: PMC8214613 DOI: 10.18502/ijph.v50i3.5592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background To investigate the expression levels of microRNA-146b (miR-146b) and cardiac troponin I (anti-cTnI) in serum of children with viral myocarditis and their clinical significance. Methods Forty-eight children with viral myocarditis (patient group) and 40 healthy physical examinees (healthy group), who were diagnosed in Jinan City People's Hospital Affiliated to Shandong First Medical University, China from Feb 2018 to May 2019, were enrolled as study subjects. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the level of miR-146b in serum of children. ELISA was used to detect the expression of anti-cTnI in serum of children. Pearson was used to analyze the correlation between the level of miR-146b and the level of anti-cTnI, and the factors affecting the prognosis. Results The levels of miR-146b and anti-cTnI in serum of children in patient group were statistically significantly higher than those of healthy group (P<0.01). The AUC of miR-146b was 0.741, (95% CI: 0.638-0.843), the specificity was 62.50%, the sensitivity was 82.50%, and the AUC of anti-cTnI was 0.720 (95% CI: 0.608-0.832), the specificity was 64.58% and the sensitivity was 92.50%. The level of miR-146b was positively correlated with the level of anti-cTnI (r=0.601, P<0.05). CK-MB, LVEF, miR-146b and anti-cTnI expression were independent risk factors affecting the prognosis. Conclusion The levels of miR-146b and anti-cTnI increased in serum of patients with viral myocarditis. They were related to the degree of myocardial injury, which indicated that miR-146b and anti-cTnI might be involved in the pathological process of viral myocarditis.
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Affiliation(s)
- Min Yan
- Department of Pediatrics, Jinan City People's Hospital Affiliated to Shandong First Medical University, Jinan 271199, China
| | - Jing Wang
- Department of Physical Examination, the People's Hospital of Zhangqiu Area, Jinan 250200, China
| | - Suyun Wang
- Ward of Emergency, the People's Hospital of Zhangqiu Area, Jinan 250200, China
| | - Yang Zhang
- Department of Respiratory Medicine, the People's Hospital of Zhangqiu Area, Jinan 250200, China
| | - Ling Liu
- EEG Room, the People's Hospital of Zhangqiu Area, Jinan 250200, China
| | - Hua Zhao
- Department of Ophthalmology, People's Hospital of Weifang, Weifang 261041, China
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Perrone MA, Storti S, Salvadori S, Pecori A, Bernardini S, Romeo F, Guccione P, Clerico A. Cardiac troponins: are there any differences between T and I? J Cardiovasc Med (Hagerstown) 2021; 22:797-805. [PMID: 33399346 DOI: 10.2459/jcm.0000000000001155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The most recent international guidelines recommend the measurement of cardiac troponin I (cTnI) and cardiac troponin T (cTnT) using high-sensitivity methods (hs-cTn) for the detection of myocardial injury and the differential diagnosis of acute coronary syndromes. Myocardial injury is a prerequisite for the diagnosis of acute myocardial infarction, but also a distinct entity. The 2018 Fourth Universal Definition of Myocardial Infarction states that myocardial injury is detected when at least one value above the 99th percentile upper reference limit is measured in a patient with high-sensitivity methods for cTnI or cTnT. Not infrequently, increased hs-cTnT levels are reported in patients with congenital or chronic neuromuscular diseases, while the hs-cTnI values are often in the normal range. Furthermore, some discrepancies between the results of laboratory tests for the two troponins are occasionally found in individuals apparently free of cardiac diseases, and also in patients with cardiac diseases. In this review article, authors discuss the biochemical, pathophysiological and analytical mechanisms which may cause discrepancies between hs-cTnI and hs-cTnT test results.
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Affiliation(s)
- Marco A Perrone
- Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children's Hospital IRCCS Division of Cardiology, University of Rome Tor Vergata, Rome CNR-Regione Toscana G. Monasterio Foundation, Heart Hospital, Massa, and Scuola Superiore Sant'Anna CNR Institute of Clinical Physiology, Pisa Division of Clinical Biochemistry and Clinical Molecular Biology, University of Rome Tor Vergata, Rome, Italy
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Miyashita K, Lutz J, Hudgins LC, Toib D, Ashraf AP, Song W, Murakami M, Nakajima K, Ploug M, Fong LG, Young SG, Beigneux AP. Chylomicronemia from GPIHBP1 autoantibodies. J Lipid Res 2020; 61:1365-1376. [PMID: 32948662 PMCID: PMC7604722 DOI: 10.1194/jlr.r120001116] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Some cases of chylomicronemia are caused by autoantibodies against glycosylphosphatidylinositol-anchored HDL binding protein 1 (GPIHBP1), an endothelial cell protein that shuttles LPL to the capillary lumen. GPIHBP1 autoantibodies prevent binding and transport of LPL by GPIHBP1, thereby disrupting the lipolytic processing of triglyceride-rich lipoproteins. Here, we review the "GPIHBP1 autoantibody syndrome" and summarize clinical and laboratory findings in 22 patients. All patients had GPIHBP1 autoantibodies and chylomicronemia, but we did not find a correlation between triglyceride levels and autoantibody levels. Many of the patients had a history of pancreatitis, and most had clinical and/or serological evidence of autoimmune disease. IgA autoantibodies were present in all patients, and IgG4 autoantibodies were present in 19 of 22 patients. Patients with GPIHBP1 autoantibodies had low plasma LPL levels, consistent with impaired delivery of LPL into capillaries. Plasma levels of GPIHBP1, measured with a monoclonal antibody-based ELISA, were very low in 17 patients, reflecting the inability of the ELISA to detect GPIHBP1 in the presence of autoantibodies (immunoassay interference). However, GPIHBP1 levels were very high in five patients, indicating little capacity of their autoantibodies to interfere with the ELISA. Recently, several GPIHBP1 autoantibody syndrome patients were treated successfully with rituximab, resulting in the disappearance of GPIHBP1 autoantibodies and normalization of both plasma triglyceride and LPL levels. The GPIHBP1 autoantibody syndrome should be considered in any patient with newly acquired and unexplained chylomicronemia.
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Affiliation(s)
- Kazuya Miyashita
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Japan
- Immuno-Biological Laboratories (IBL), Fujioka, Gunma, Japan
| | - Jens Lutz
- Medical Clinic, Nephrology-Infectious Diseases, Central Rhine Hospital Group, Koblenz, Germany
| | - Lisa C Hudgins
- Rogosin Institute, Weill Cornell Medical College, New York, NY, USA
| | - Dana Toib
- Department of Pediatrics, Drexel University, Philadelphia, PA, USA
- Section of Pediatric Rheumatology, St. Christopher's Hospital for Children, Philadelphia, PA, USA
| | - Ambika P Ashraf
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wenxin Song
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Japan
| | - Katsuyuki Nakajima
- Department of Clinical Laboratory Medicine, Gunma University, Graduate School of Medicine, Maebashi, Japan
| | - Michael Ploug
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark
- Biotechnology Research Innovation Center, Copenhagen University, Copenhagen, Denmark
| | - Loren G Fong
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Anne P Beigneux
- Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
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7
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Abstract
The measurement of cardiac troponin (cTn) is recommended by all guidelines as the gold standard for the differential diagnosis of Acute Coronary Syndromes. The aim of this review is to discuss in details some key issues regarding both analytical and clinical characteristics of the high-sensitivity methods for cTn (hs-cTn), which are still considered controversial or unresolved. In particular, the major clinical concern regarding hs-cTn methods is the difficulty to differentiate the pathophysiological mechanism responsible for biomarker release from cardiomyocytes after reversible or irreversible injury, respectively. Indeed, recent experimental and clinical studies have demonstrated that different circulating forms of cTnI and cTnT can be respectively measured in plasma samples of patients with reversible or irreversible myocardial injury. Accordingly, a new generation of hs-Tn methods should be set up, based on immunometric immunoassays or chromatographic techniques, specific for circulating peptide forms more characteristics for reversible or irreversible myocardial injury. It is conceivable that this new generation of hs-cTn methods will complete the mission regarding the laboratory tests for specific cardiac biomarkers, started more than 20 years ago, which has already revolutionized the diagnosis, prognosis and management of patients with cardiac diseases.
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8
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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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Wu Y, Qin YH, Liu Y, Zhu L, Zhao XX, Liu YY, Luo SW, Tang GS, Shen Q. Cardiac troponin I autoantibody induces myocardial dysfunction by PTEN signaling activation. EBioMedicine 2019; 47:329-340. [PMID: 31474552 PMCID: PMC6796505 DOI: 10.1016/j.ebiom.2019.08.045] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/02/2019] [Accepted: 08/21/2019] [Indexed: 01/22/2023] Open
Abstract
Background The objective of the current study was to study the molecular mechanism(s) underlying cardiac troponin I autoantibody (cTnIAAb) binding to cardiomyocyte and resultant myocardial damage/dysfunction. Methods cTnIAAb was purified from serum of 10 acute myocardial infarction (AMI) patients with left ventricular remodeling. Recombinant human cTnI was used to generate three mouse-derived monoclonal anti-cTnI antibodies (cTnImAb1, cTnImAb2, and cTnImAb3). The target proteins in cardiac myocyte membrane bound to cTnImAb and effect of cTnIAAb and cTnImAb on apoptosis and myocardial function were determined. Findings We found that cTnIAAb/cTnImAb1 directly bound to the cardiomyocyte membraneα-Enolase (ENO1) and triggered cell apoptosis via increased expression of ENO1 and Bax, decreased expression of Bcl2, subsequently activating Caspase8, Caspase 3, phosphatase and tensin homolog (PTEN) while inhibiting Akt activity. This cTnIAAb-ENO1-PTEN-Akt signaling axis contributed to increased myocardial apoptosis, myocardial collagen deposition, and impaired systolic dysfunction. Interpretation Results obtained in this study indicate that cTnIAAb is involved in the process of ventricular remodeling after myocardial injury. Fund The National Natural Science Foundation of China (Grant#: 81260026).
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Affiliation(s)
- Yu Wu
- Outpatient Department, Changcheng Hospital, Nanchang University, Nanchang, Jiangxi 330002, China; Department of Laboratory Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Yang-Hua Qin
- Department of Laboratory Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Yang Liu
- Department of Cardiothoracic Surgery, Changhai Hospital, Second military Medical University, Shanghai 200433, China
| | - Li Zhu
- Department of Laboratory Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, China; Department of Laboratory Medicine, Wuxi First People Hospital, Wuxi, Jiangsu 214002, China
| | - Xian-Xian Zhao
- Department of Cardiology, Changhai Hospital, Second military Medical University, Shanghai 200433, China
| | - Yao-Yang Liu
- Department of Rheumatology, Changzheng Hospital, Second military Medical University, Shanghai 200003, China
| | - Shi-Wen Luo
- Research Center, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Gu-Sheng Tang
- Department of Hematology, Changhai Hospital, Second military Medical University, Shanghai 200433, China.
| | - Qian Shen
- Department of Laboratory Medicine, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.
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Vilela EM, Bettencourt-Silva R, da Costa JT, Barbosa AR, Silva MP, Teixeira M, Primo J, Gama Ribeiro V, Nunes JPL. Anti-cardiac troponin antibodies in clinical human disease: a systematic review. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:307. [PMID: 28856147 DOI: 10.21037/atm.2017.07.40] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Anti-cardiac troponin antibodies have been studied in different types of clinical diseases and in healthy populations. A systematic review of published data on anti-troponin antibodies was carried out (search performed on PubMed, ISI Web of Knowledge and Scopus databases). From title and abstract analysis, thirty-three articles were included that met the pre-specified criteria; after full-text analysis, nine articles were excluded. Most studies assessed anti-troponin I antibodies. The prevalence of anti-cardiac troponin antibodies in healthy individuals ranged from 0.0% to 20.0%. The prevalence of anti-troponin I autoantibodies in dilated cardiomyopathy (DCM) ranged from 7.0% to 22.2%. Other conditions under study were myocardial infarction, ischemic cardiomyopathy (ICM), peripartum cardiomyopathy (PPCM), Chagas disease, Emery-Dreifuss muscular dystrophy (EDMD) and renal transplantation. In the different patient populations studied, anti-cardiac troponin antibodies have been shown to be either positively or negatively associated with prognostic and clinical features. In what concerns a possible value as biomarkers, these assays have not emerged up to the present moment as important aids for practical clinical decisions in cardiac or other types of patients. In what concerns pathophysiology, anti-cardiac troponin autoantibodies may play a role in different diseases. It can be speculated that these antibodies could be involved in perpetuating some degree of cardiac injury after an event, such as myocardial infarction or PPCM.
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Affiliation(s)
- Eduardo M Vilela
- Department of Cardiology, Centro Hospitalar V.N. Gaia/Espinho, Gaia, Portugal
| | | | - J Torres da Costa
- Centro Hospitalar São João, Porto, Portugal.,Faculdade de Medicina da Universidade do Porto, Porto, Portugal
| | - Ana Raquel Barbosa
- Department of Cardiology, Centro Hospitalar V.N. Gaia/Espinho, Gaia, Portugal
| | - Marisa P Silva
- Department of Cardiology, Centro Hospitalar V.N. Gaia/Espinho, Gaia, Portugal
| | - Madalena Teixeira
- Department of Cardiology, Centro Hospitalar V.N. Gaia/Espinho, Gaia, Portugal
| | - João Primo
- Department of Cardiology, Centro Hospitalar V.N. Gaia/Espinho, Gaia, Portugal
| | - Vasco Gama Ribeiro
- Department of Cardiology, Centro Hospitalar V.N. Gaia/Espinho, Gaia, Portugal
| | - José Pedro L Nunes
- Centro Hospitalar São João, Porto, Portugal.,Faculdade de Medicina da Universidade do Porto, Porto, Portugal
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11
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O’Donohoe TJ, Ketheesan N, Schrale RG. Anti-troponin antibodies following myocardial infarction. J Cardiol 2017; 69:38-45. [DOI: 10.1016/j.jjcc.2016.07.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/09/2016] [Accepted: 07/22/2016] [Indexed: 12/22/2022]
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12
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Loh TP, Lim XC, Kieu K, Sajiir H, Neo SF, Cheng WL, Sethi SK. Recovery of spiked troponin I in four routine assays. Biochem Med (Zagreb) 2016; 26:233-9. [PMID: 27346968 PMCID: PMC4910266 DOI: 10.11613/bm.2016.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/25/2016] [Indexed: 11/23/2022] Open
Abstract
Introduction This study aimed to examine the recovery of spiked human cardiac troponin I (cTnI) results measured by four routine assays, and investigate possible interference from microclots. Materials and methods 457 consecutive samples with cTnI concentration below limit of quantitation (12 ng/L), declared by the Vitros TnI ES assay (reference assay), were measured on Beckman Coulter Accu TnI+3, Siemens TnI-Ultra and Roche TnI STAT assays. These samples were enriched with native full-length cTnI to a concentration of 100 ng/L and retested. A post-spiking result that exceeded the critical difference at a predefined probability of 0.0005 of the target concentration (the median post-spiking result for each individual assay) was considered as outlier. To determine whether microclots were a significant cause of critically discrepant outlier results, a separate 50 samples were centrifuged twice between two post-spiking measurements using the Vitros TnI ES assay. Results The median recovery of the enriched cTnI was highest with the Roche assay (271 ng/L) and lowest with the Vitros assay (29 ng/L). The Vitros assay had the highest percentage of results that exceeded the critical difference (49%), followed by the Siemens (38%), Roche (18%) and Beckman Coulter (7%) assays. None of the 50 additional samples produced a critically lower cTnI result after re-centrifugation. Conclusions Our findings underscored the variability of cTnI assays in measuring native cTnI. The lack of cTnI results that became significantly lower after re-centrifugation suggested that microclots are unlikely to be a major cause of the outlier results.
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Affiliation(s)
- Tze Ping Loh
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Xiong Chang Lim
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Karize Kieu
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Haressh Sajiir
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Siew Fong Neo
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Wan Ling Cheng
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
| | - Sunil Kumar Sethi
- Department of Laboratory Medicine, National University Hospital, Singapore, Singapore
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13
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Shalaby SM, El-Shal AS, Shoukry A, Khedr MH, Abdelraheim N. Serum miRNA-499 and miRNA-210: A potential role in early diagnosis of acute coronary syndrome. IUBMB Life 2016; 68:673-82. [DOI: 10.1002/iub.1529] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/06/2016] [Accepted: 06/06/2016] [Indexed: 01/03/2023]
Affiliation(s)
- Sally M. Shalaby
- Medical Biochemistry Department, Faculty of Medicine; Zagazig University; Zagazig Egypt
| | - Amal S. El-Shal
- Medical Biochemistry Department, Faculty of Medicine; Zagazig University; Zagazig Egypt
| | - Amira Shoukry
- Internal Medicine Department, Faculty of Medicine; Zagazig University; Zagazig Egypt
| | - Mohamad H. Khedr
- Cardiology Department, Faculty of Medicine; Zagazig University; Zagazig Egypt
| | - Nader Abdelraheim
- Cardiothoracic Surgery Department, Faculty of Medicine; Zagazig University Zagazig; Egypt
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O'Donohoe TJ, Schrale RG, Ketheesan N. The role of anti-myosin antibodies in perpetuating cardiac damage following myocardial infarction. Int J Cardiol 2016; 209:226-33. [PMID: 26897075 DOI: 10.1016/j.ijcard.2016.02.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 12/21/2015] [Accepted: 02/02/2016] [Indexed: 12/17/2022]
Abstract
Recent improvements in the medical and surgical management of myocardial infarction mean that many patients are now surviving with greater impairment of cardiac function. Despite appropriate management, some of these patients subsequently develop pathological ventricular remodelling, which compounds their contractile dysfunction and can lead to congestive cardiac failure (CCF). The pathophysiological mechanism underpinning this process remains incompletely understood. One hypothesis suggests that a post-infarction autoimmune response, directed against constituents of cardiac myocytes, including cardiac myosin, may make an important contribution. Our review summarises the current literature related to the formation and clinical relevance of anti-myosin antibodies (AMAs) in patients with myocardial infarction. This discussion is supplemented with reference to a number of important animal studies, which provide evidence of the potential mechanisms underlying AMA formation and autoantibody mediated cardiac dysfunction.
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Affiliation(s)
- Tom J O'Donohoe
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland 4811, Australia; Department of Cardiology, The Townsville Hospital and Health Service, Townsville, Queensland 4811, Australia
| | - Ryan G Schrale
- Department of Cardiology, The Townsville Hospital and Health Service, Townsville, Queensland 4811, Australia; College of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811, Australia
| | - Natkunam Ketheesan
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, Queensland 4811, Australia; College of Medicine and Dentistry, James Cook University, Townsville, Queensland 4811, Australia; College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia.
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15
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Warner JV, Marshall GA. High incidence of macrotroponin I with a high-sensitivity troponin I assay. ACTA ACUST UNITED AC 2016; 54:1821-1829. [DOI: 10.1515/cclm-2015-1276] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/16/2016] [Indexed: 11/15/2022]
Abstract
AbstractBackground:Cardiac troponin is the preferred biomarker of myocardial injury. High-sensitivity troponin assays allow measurement of very low levels of troponin with excellent precision. After the introduction of a high-sensitivity troponin I assay the laboratory began to receive enquiries from clinicians about clinically discordant elevated troponin I results. This led to a systematic investigation and characterisation of the cause.Methods:Routine clinical samples were measured by the Architect High Sensitive Troponin-I (hsTnI) and the VITROS Troponin I ES assays (VitrosTnI). Results that were elevated according to the Architect but not the VITROS assay (Group 1) or results elevated by both assays but disproportionately higher on the Architect (Group 2) were re-analysed for hsTnI after re-centrifugation, multiple dilutions, incubation with heterophilic blocking reagents, polyethylene glycol (PEG) precipitation, and Protein A/G/L treatment. Sephacryl S-300 HR gel filtration chromatography (GFC) was performed on selected specimens.Results:A high molecular weight complex containing immunoreactive troponin I and immunoglobulin (macrotroponin I) was identified in 5% of patients with elevated hsTnI. Patients with both macrotroponin and myocardial injury had higher and longer elevation of hsTnI compared with VitrosTnI with peaks of both macrotroponin and free troponin I-C complex on GFC.Conclusions:Circulating macrotroponin I (macroTnI) causes elevated hsTnI results with the Architect High Sensitive Troponin-I assay with the potential to be clinically misleading. The assay involved in this investigation may not be the only assay affected by macrotroponin. It is important for laboratories and clinicians to be aware of and develop processes to identify and manage specimens with elevated results due to macrotroponin.
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Zhang L, Chen X, Su T, Li H, Huang Q, Wu D, Yang C, Han Z. Circulating miR-499 are novel and sensitive biomarker of acute myocardial infarction. J Thorac Dis 2015; 7:303-8. [PMID: 25922707 DOI: 10.3978/j.issn.2072-1439.2015.02.05] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/12/2015] [Indexed: 12/31/2022]
Abstract
BACKGROUND miRNAs are known to play a crucial role in cardiac development, and the expression of miRNA is altered in the diseased heart. The aim of this study was to investigate the value of plasma microRNA-499 (miR-499) as a novel biomarker for early diagnosis of acute myocardial infarction (AMI). METHODS Enrolled in this study were 227 patients with chest pain on presentation to the departments of emergency and cardiology of Wuxi Second People's Hospital between October 2011 and May 2014. Additional 100 healthy individuals who received physical examination in the same hospital during the same period were used as control. Plasma was collected at admission, and the abundance of miR-499 was measured using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS MiR-499 was significantly elevated in 142 patients diagnosed with AMI as compared with 85 patients in non-AMI group and 100 subjects in healthy control group. Plasma miR-499 were already detectable in the plasma as early as 1 h after onset of chest pain in AMI patients, and continued to increase gradually without any sign of decreasing tendency within 9 h in AMI patients. miR-499 was highly positively correlated with the serum creatine kinase-MB (CK-MB) and cTnI. The area under the curve (AUC) of miR-499 for the diagnosis of AMI was 0.86, with an optimal cut-off value of 4.79, sensitivity of 80%, and specificity of 80.28%. CONCLUSIONS miR-499 was shown to substantially increase the diagnostic accuracy of CK-MB and cTnI in the diagnosis of AMI, and therefore it may prove to be a useful marker for early diagnosis of AMI.
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Affiliation(s)
- Lizhu Zhang
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Xi Chen
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Tong Su
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Heng Li
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Qiang Huang
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Dan Wu
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Chengjian Yang
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
| | - Zhijun Han
- 1 Department of Cardiology, 2 Department of Laboratory Medicine, Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214002, China
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Savukoski T, Twarda A, Hellberg S, Ristiniemi N, Wittfooth S, Sinisalo J, Pettersson K. Epitope Specificity and IgG Subclass Distribution of Autoantibodies to Cardiac Troponin. Clin Chem 2013; 59:512-8. [DOI: 10.1373/clinchem.2012.194860] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND
Autoantibodies to cardiac troponins (cTnAAbs) can interfere with the measurement of cardiac troponin I (cTnI) by immunoassays for the diagnosis of myocardial infarction. Therefore, we determined the cTnI binding sites and IgG subclasses of circulating cTnAAbs.
METHODS
We studied epitope specificity with sandwich-type immunoassays by measuring the recovery of troponin complex added to 10 cTnAAb-negative and 10 cTnAAb-positive sera from healthy volunteers. To study the IgG subclasses, we analyzed admission and 3-month follow-up sera from chest pain patients with a reference assay measuring total IgG (14 cTnAAb negative and 14 cTnAAb positive at 3 months) and with 4 subclass-specific assays measuring exclusively IgG subclasses 1–4.
RESULTS
Mean recoveries of troponin complex in cTnAAb-positive samples for single cTnI epitopes ranged from 37% to 211%, being lowest for the cTnI midfragment (aa 30–110). However, the lowest sample-specific recoveries, 4%–92%, showed that none of the studied epitopes completely escaped the cTnAAb-related interference. Eight chest pain patients of the cTnAAb-positive group became positive between sampling points, and according to all 5 cTnAAb assays, specific signals were generally higher at follow-up. IgG4, with the highest prevalence, was detected in 68% of samples in the cTnAAb-positive group.
CONCLUSIONS
IgG subclass studies confirm that cTnAAb formation may be triggered/boosted in acute cardiac events. This new information about the epitope specificity of cTnAAbs should be used to reevaluate existing recommendations regarding use of midfragment epitopes in cTnI assays. To circumvent the negative interference of the highly heterogeneous cTnAAbs, use of 3 or more unconventionally selected epitopes should be considered.
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Affiliation(s)
- Tanja Savukoski
- Department of Biotechnology, University of Turku, Turku, Finland
| | | | - Sanna Hellberg
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Noora Ristiniemi
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Saara Wittfooth
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Juha Sinisalo
- Juha Sinisalo, Division of Cardiology, Helsinki University Central Hospital, Helsinki, Finland
| | - Kim Pettersson
- Department of Biotechnology, University of Turku, Turku, Finland
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18
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Eerola A, Jokinen EO, Savukoski TI, Pettersson KSI, Poutanen T, Pihkala JI. Cardiac troponin I in congenital heart defects with pressure or volume overload. SCAND CARDIOVASC J 2012; 47:154-9. [DOI: 10.3109/14017431.2012.751506] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Savukoski T, Engström E, Engblom J, Ristiniemi N, Wittfooth S, Lindahl B, Eggers KM, Venge P, Pettersson K. Troponin-Specific Autoantibody Interference in Different Cardiac Troponin I Assay Configurations. Clin Chem 2012; 58:1040-8. [DOI: 10.1373/clinchem.2011.179226] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
BACKGROUND
Autoantibodies to cardiac troponins (cTnAAb) can interfere with the measurement of cardiac troponin I (cTnI) by immunoassays. The aim of this study was to explore the degree of cTnAAb interference in different cTnI assay configurations.
METHODS
Ternary troponin complex was added into samples (serum or plasma, n = 132, 68% cTnAAb positive) from individuals without known cardiac conditions. The recovery of cTnI was then measured with 6 investigational cTnI assays (2, 3, or 4 antibodies per assay). Three of these assays were then selected for further comparison by use of samples (plasma, n = 210, 33% cTnAAb positive) from non–ST-elevation acute coronary syndrome patients in the FRISC-II (FRagmin/Fast Revascularisation during InStability in Coronary artery disease) cohort. Finally, these results were compared to those obtained with 3 commercial cTnI assays.
RESULTS
Analytical recoveries varied widely among the 6 investigational assays. Notably the low recoveries (median 9%) of the midfragment-targeting reference assay were normalized (median 103%) with the use of the 4-antibody assay construct (3 capture, 1 tracer antibody) with only 1 antibody against a midfragment epitope. Reduced analytical recoveries correlated closely with measured autoantibody amounts. cTnI concentrations from cTnAAb-positive patient samples determined with 3 investigational assays confirmed the reduced concentrations expected from the low analytical recoveries. The results from the commercial cTnI assays with antibody selections representative for contemporary assay constructs revealed a similar underestimation (up to 20-fold) of cTnI in cTnAAb-positive samples.
CONCLUSIONS
A novel cTnI assay deviating from the conventional IFCC-recommended midfragment approach substantially improves cTnI detection in samples containing cTnAAbs.
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Affiliation(s)
- Tanja Savukoski
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Emilia Engström
- Department of Biotechnology, University of Turku, Turku, Finland
| | | | - Noora Ristiniemi
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Saara Wittfooth
- Department of Biotechnology, University of Turku, Turku, Finland
| | - Bertil Lindahl
- Department of Medical Sciences, Clinical Chemistry, University of Uppsala, Uppsala, Sweden
| | - Kai M Eggers
- Department of Medical Sciences, Clinical Chemistry, University of Uppsala, Uppsala, Sweden
| | - Per Venge
- Department of Medical Sciences, Clinical Chemistry, University of Uppsala, Uppsala, Sweden
| | - Kim Pettersson
- Department of Biotechnology, University of Turku, Turku, Finland
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