High-sensitivity cardiac troponins in everyday clinical practice

High-sensitivity cardiac troponin(hs-cTn) assays are increasingly being used in many countries worldwide,however,a generally accepted definition of high-sen-sitivity is still pending.These assays enable cTn mea-surement with a high degree of analytical sensitivity with a low analytical imprecision at the low measuring range of cTn assays(coefficient of variation of < 10% at the 99th percentile upper reference limit).One of the most important advantages of these new assays is that they allow novel,more rapid approaches to rule in or rule out acute coronary syndromes(ACSs) than with previous cTn assay generations which are still more commonly used in practice worldwide.hs-cTn is also more sensitive for the detection of myocardial damage unrelated to acute myocardial ischemia.Therefore,the increase in early diagnostic sensitivity of hs-cTn assays for ACS comes at the cost of a reduced ACS specificity,because more patients with other causes of acute or chronic myocardial injury without overt myocardial isch-emia are detected than with previous cTn assays.As hs-cTn assays are increasingly being adopted in clinical practice and more hs-cTn assays are being developed,this review attempts to synthesize the available clinical data to make recommendations for their everyday clini-cal routine use.

Comparison of plasma microRNA-1 and cardiac troponin T in early diagnosis of patients with acute myocardial infarction

BACKGROUND:Early reperfusion can effectively treat acute myocardial infarction(AMI) and reduce the mortality signif icantly. This study aimed to compare the role of plasma microRNA-1(miR-1) and cardiac troponin T(cTnT) in early diagnosis of AMI patients.METHODS:From May 2011 to May 2012,plasma samples were collected from 56 AMI patients and 28 non-AMI controls. The expression of plasma miR-1 was measured by quantitative reverse transcription-polymerase chain reaction(qRT-PCR),and the level of plasma cTnT was measured using electrochemiluminescence-based methods on an Elecsys 2010 Immunoassay Analyzer. SPSS 16.0 was used for the statistical analysis of the results. Data were expressed as mean±standard deviation unless otherwise described. The differences about clinical characteristics between the AMI patients and controls were tested using Student's t test or Fisher's exact test. The Mann-Whitney U test was conducted to compare the expression of microRNAs between the AMI patients and controls. MicroRNAs expression between different intervals of the AMI patients was compared using Wilcoxon's signed-rank test. The receiver operating characteristic(ROC) curve was established to discriminate the AMI patients from the controls.RESULTS:In the present study,the expression of plasma miR-1 was signifi cantly increased in the AMI patients compared with the healthy controls(P<0.01). The plasma miR-1 in the AMI patients decreased to the normal level at 14 days(P>0.05). The expression of plasma miR-1 was not related to the clinical characteristics of the study population(P>0.05). ROC curve analyses demonstrated that miR-1 was specifi c and sensitive for the early diagnosis of AMI,but not superior to cTnT.CONCLUSION:Plasma miR-1 could be used in the early diagnosis of AMI,but it is similar to cTnT.

The combination of creatine kinase-myocardial band isoenzyme and point-of-care cardiac troponin/contemporary cardiac troponin for the early diagnosis of acute myocardial infarction

BACKGROUND:The early diagnosis of acute myocardial infarction(AMI)remains challenging,especially for institutions without the high-sensitive cardiac troponin(hs-c Tn)assay.Herein,we aim to assess the value of creatine kinase-myocardial band isoenzyme(CK-MB)combined with different cardiac troponin(c Tn)assays in AMI diagnosis.METHODS:This multicenter,observational study included 3,706 patients with acute chest pain from September 1,2015,to September 30,2017.We classified the participants into three groups according to the c Tn assays:the point-of-care c Tn(POC-c Tn)group,the contemporary c Tn(c-c Tn)group,and hs-c Tn group.The diagnostic value was quantified using sensitivity and the area under the curve(AUC).RESULTS:Compared to the single POC-c Tn/c-c Tn assays,combining CK-MB and POC-c Tn/c-c Tn increased the diagnostic sensitivity of AMI(56.1%vs.63.9%,P<0.001;82.7%vs.84.3%,P=0.025).In contrast,combining CK-MB and hs-c Tn did not change the sensitivity compared with hs-c Tn alone(95.0%vs.95.0%,P>0.999).In the subgroup analysis,the sensitivity of combining CKMB and c-c Tn increased with time from symptom onset<6 h compared with c-c Tn alone(72.8%vs.75.0%,P=0.046),while the sensitivity did not increase with time from symptom onset>6 h(97.5%vs.98.3%,P=0.317).The AUC of the combination of CK-MB and POC-c Tn significantly increased compared to the single POC-c Tn assay(0.776 vs.0.750,P=0.002).The AUC of the combined CKMB and c-c Tn/hs-c Tn assays did not significantly decrease compared with that of the single c-c Tn/hs-c Tn assays within 6 h.CONCLUSIONS:The combination of CK-MB and POC-c Tn or c-c Tn may be valuable for the early diagnosis of AMI,especially when hs-c Tn is not available.

Characteristics of elevated cardiac troponin I in patients with acute ischemic stroke

Objective To study prognostic characteristics of cardiac troponin I （cTnI） elevation in acute ischemic stroke. Methods We retrospectively studied patients （n = 248） with acute ischemic stroke, acute ST-segment elevation myocardial infarction, and acute non-ST-elevation myocardial infarction who were treated between January 2013 and October 2015. Baseline demographic data and changes in cTnI levels among these three groups were compared. Patients with acute ischemic stroke were assigned to either the cTnI elevation group （cTnI 〉 0.034 ng/mL） or the no cTnI elevation group （cTnI ≤ 0.034 ng/mL）. Logistic regression analysis was used to identify risk factors associated with elevated serum cTnI in patients with acute ischemic stroke. Moreover, the duration of hospital stay and incidence of major cardiovascular outcomes were compared in patients with acute ischemic stroke, with or without elevated cTnI. Results In this study population of patients with acute ischemic stroke （n = 178）, acute ST-segment elevation myocardial infarction （n = 35）, and acute non-ST-elevation myocardial infarction （n = 35）, patients with acute ischemic stroke with elevated cTnI comprised 18.54% of subjects. Patients with elevated cTnI were older and more likely to have a history of hypertension. In addition, these patients had higher levels of inflammatory markers, reduced renal functions, increased D-dimer levels, higher NIH stroke scores, and lower left ventricular ejection fractions. Logistic regression analysis showed that both percentage of neutrophil and NIH stroke scores were elevated; estimated glomerular filtration rate and left ventricular ejection fraction were decreased in patients with acute ischemic stroke who had elevated cTnI, and they had more frequent major cardiovascular events during hospital stay. Conclusion Elevated cTnI detected in patients with acute ischemic stroke, indicated a greater likelihood of poor short-term prognosis during hospital stay.

A MXene-functionalized paper-based electrochemical immunosensor for label-free detection of cardiac troponin I

Convenient,rapid,and accurate detection of cardiac troponin I(cTnI)is crucial in early diagnosis of acute myocardial infarction(AMI).A paper-based electrochemical immunosensor is a promising choice in this field,because of the flexibility,porosity,and cost-efficacy of the paper.However,paper is poor in electronic conductivity and surface functionality.Herein,we report a paper-based electrochemical immunosensor for the label-free detection of cTnI with the working electrode modified by MXene(Ti_(3)C_(2))nanosheets.In order to immobilize the bio-receptor(anti-cTnI)on the MXene-modified working electrode,the MXene nanosheets were functionalized by aminosilane,and the functionalized MXene was immobilized onto the surface of the working electrode through Nafion.The large surface area of the MXene nanosheets facilitates the immobilization of antibodies,and the excellent conductivity facilitates the electron transfer between the electrochemical species and the underlying electrode surface.As a result,the paper-based immunosensor could detect cTnI within a wide range of 5-100 ng/mL with a detection limit of 0.58 ng/mL.The immunosensor also shows outstanding selectivity and good repeatability.Our MXene-modified paper-based electrochemical immunosensor enables fast and sensitive detection of cTnI,which may be used in real-time and cost-efficient monitoring of AMI diseases in clinics.

Prognostic value of high-sensitivity cardiac troponin T in patients with en-domyocardial-biopsy proven cardiac amyloidosis

Objective To investigate prognostic predictors of long-term survival of patients with cardiac amyloidosis （CA）, and to determine predictive value of high-sensitivity cardiac troponin T （hs-cTnT） in CA patients. Methods We recruited 102 consecutive CA cases and followed these patients for 5 years. We described their clinical characteristics at presentation and used a new, high-sensitivity assay to determine the concentration of cTnT in plasma samples from these patients. Results The patients with poor prognosis showed older age （56 ±12 years vs. 50 ±15 years, P=0.022）, higher incidences of heart failure （36.92%vs. 16.22%, P=0.041）, pericardial effusion （60.00%vs. 35.14%, P=0.023）, greater thickness of interventricular septum （IVS） （15 ±4 mm vs. 13 ±4 mm, P=0.034）, higher level of hs-cTnT （0.186 ±0.249 ng/mL vs. 0.044 ±0.055 ng/mL, P=0.001） and higher NT-proBNP （N-terminal pro-B-type natriuretic pep-tide） levels （11,742 ± 10,464 pg/mL vs. 6,031 ± 7,458 pg/mL, P=0.006）. At multivariate Cox regression analysis, heart failure （HR：1.78, 95%CI：1.09-2.92, P=0.021）, greater wall thickness of IVS （HR：1.44, 95%CI：1.04-3.01, P=0.0375） and higher hs-cTnT level （HR：6.16, 95%CI：2.20-17.24, P=0.001） at enrollment emerged as independent predictors of all-cause mortality. Conclusions We showed that hs-cTnT is associated with a very ominous prognosis, and it is also the strongest predictor of all-cause mortality in multivariate analysis. Examination of hs-cTnT concentrations provides valuable prognostic information concerning long-term outcomes.

Impact of training specificity on exercise-induced cardiac troponin elevation in professional athletes: A pilot study

BACKGROUND Release of cardiac biomarkers is common after strenuous endurance exercise,but data on intermittent exercise are scarce.It has not been investigated whether cardiac troponin elevation is influenced depending on the type of exercise that an athlete is adapted to perform.We hypothesized that intermittent but not continuous exercise induces cardiac troponin elevation in professional athletes adapted to high-intensity intermittent exercise.AIM To examine how training specificity impacts high-sensitivity cardiac troponin T(hs-cTnT)release.METHODS Nine professional floorball players participated in the study,which comprised two different exercise tests:a continuous incremental cycle ergometer test and a Yo-Yo Intermittent Recovery 2(Yo-Yo IR2)test.Serial assessment of hs-cTnT was performed after the cycle ergometer test and the Yo-Yo IR2 test(baseline,0,2,6,and 24 h).RESULTS No hs-cTnT elevation above the myocardial damage cutoff(≥14 ng/L)was shown after the cycle ergometer test,whereas hs-cTnT levels rose over the cutoff in three of nine participants after the Yo-Yo IR2 test.The hs-cTnT levels peaked at 6 h after both tests,but were significantly higher after the Yo-Yo IR2 test compared to the cycle ergometer test(median hs-cTnT concentration 10.6 ng/L vs 7.8 ng/L,P=0.038).All levels returned to baseline within 24 h.CONCLUSION In professional athletes adapted to high-intensity intermittent exercise,hs-cTnT was significantly elevated after intermittent but not continuous exercise.This principle of specificity training should be considered when designing future studies to avoid misinterpretation of hs-cTnT elevation.

Troponin based studies in search of a biomarker for cardiac arrest

Cardiac arrest is shown to be a cause of a large number of deaths not only in Pakistan but around the globe. The prevalence of this dis-ease demands identification of its etiology. The science of proteomics can be used to identify cardiac specific proteins. The subsequent over expression or under expression of these pro-teins can be utilized as targets not only for therapeutical interventions but also for identi-fying molecular signatures for Cardiac diseases. In context of a number of studies which have shown that the specificity of serum biomarkers like troponin (cTnI and cTnT) are questionable as they may also appear in serum in pathologi-cal conditions other than cardiac dysfunction, the search of a specific marker for cardiac arrest becomes imperative. In this study protein pro-filing of cardiac arrest patients was performed after its quantification through Bradford assay. SDS-PAGE and 2 DE techniques were used as to characterize proteins. The samples of the pa-tients prior to characterizing of proteins were subjected to lipid and cardiac enzymes profiling. The results of these investigations have shown an increase in almost all of these parameters by many folds from that of normal values. In addi-tion to this the samples were found out to be positive for troponin T which strongly confirms the incidence of the cardiac arrest. The results of SDS-PAGE exhibited the induction of three proteins of 100 kDa, 97 kDa and of 66 kDa with 100 kDa as the most highly expressed protein. In addition to that SDS-PAGE gels have shown the down regulation of 45 kDa protein, again indi-cating the changes as a result of cardiac arrest. 2DE gel patterns of cardiac arrest samples demonstrated higher number of protein spots as compare to control in the alkaline range, which might suggest their role in cardiac dysfunction. Therefore it can be concluded that this study may pave the grounds for identification of such proteins which can serve not only as potential therapeutical targets but also as candidate markers for accurate diagnosis of the disease.

Aptamer-Based Fluorescent Assay for Sensitive Detection of Cardiac Troponin Ⅰ

Acute myocardial infarction(AMI)is a major health problem leading to high rates of mortality and morbidity.Biomarker cardiac troponin I(cTnI)has shown high sensitivity and specificity towards AMI detection,and has been regarded as"gold standard".An ultrasensitive method to detectcTnI with low concentration in human fluid is essential.In this paper,we developed an aptamer-based assay coupled with rolling circle amplification(RCA)and molecular beacon probe for sensitive detection ofcTnI.In this strategy,aptamer acts as a bridge to communicate between oligonucleotides andcTnI.RCA reaction produces a single-stranded tandem repeated copy of the circular template,which are recognized by fluorescence molecular beacon probe.With this strategy,highly sensitive and specific detection of cTnI was realized with the lowest detectable concentration of 7.24 pg/m L.The developed aptamer-RCA assay can be a promising tool in clinical samples analysis.The assay can also analyze other disease-related biomarkers by replacing the aptamer.

Role of cardiac magnetic resonance imaging in troponinemia syndromes

Cardiac magnetic resonance imaging(MRI)is an evolving technology,proving to be a highly accurate tool for quantitative assessment.Most recently,it has been increasingly used in the diagnostic and prognostic evaluation of conditions involving an elevation in troponin or troponinemia.Although an elevation in troponin is a nonspecific marker of myocardial tissue damage,it is a frequently ordered investigation leaving many patients without a specific diagnosis.Fortunately,the advent of newer cardiac MRI protocols can provide additional information.In this review,we discuss several conditions associated with an elevation in troponin such as myocardial infarction,myocarditis,Takotsubo cardiomyopathy,coronavirus disease 2019 related cardiac dysfunction and athlete’s heart syndrome.

Marked elevation of troponin I without wall motion abnormality in a patient with myocarditis: Cardiac enzymes may not predict the outcome in myocarditis

A seventeen-year-old male presented with severe substernal chest pain after an episode of upper respiratory tract infection. On clinical grounds, a diagnosis of myocarditis was established. He had a peak troponin I level as high as 40.4 ng/dl but interestingly with no abnormal wall motion and normal ejection fraction in echocardiography. Coronary artery disease was excluded with normal coronary angiography. Diagnosis of myocarditis was confirmed with cardiac MRI. After one month, patient had no complaint and ejection fraction were still normal. Our case emphasizes that the troponin levels predict neither the early nor the late outcome of the left ventricular functions in myocarditis, therefore serum troponin I may not be helpful in determining the prognosis of patients with myocarditis.

Differential IFN-Gamma (IFN-γ), Interleukin 10 (IL-10) and Cardiac Troponin I (cTnI) Responses in Natural Bovine Trypanosomosis in Nigeria

Trypanosomosis is major drawback to profitable livestock production in sub-Sahara African, including Nigeria. Knowledge of the cytokines production in the phase of natural infection may help to better diagnose, treat and prevent bovine trypanosomosis. The purpose of the this study was to determine the levels of interferon-gamma (IFN-γ), interleukin-10 (IL-10) and cardiac troponin–I (cTnI) in the sera of cattle naturally infected with T. brucei, T. congolense and T. vivax and correlate these levels with parasitaemia and PCV of the infected animals. Five milliliter of blood samples were collected via the jugular vein from 411 randomly selected cattle into EDTA and non-citrated bottle. PCV was determined manually using HCT. Trypansomes were detected and characterized by microscopy and PCR, respectively. Serum levels of IFN-γ, IL-10 and cTnI were determined using commercial ELISA kit. Data were summarized using descriptive statistic and significance of differences determined by ANOVA. Of the 62 samples positive for trypanosomes by microscopy, 50 samples were confirmed to species level by PCR. The sera levels of IFN-γ, IL-10 and cTnI of infected cattle were higher than non-infected cattle. The differences were not significant (p γ, IL-10 and cTnI in cattle with natural trypanosomosis. Further investigation is required to understand the specific effect of trypanosomes on myocardiac integrity and interaction between the two cytokines in natural trypanosomosis in cattle.

Correlation of cardiac troponin T levels with inotrope requirement,hypoxic-ischemic encephalopathy,and survival in asphyxiated neonates

BACKGROUND Cardiac involvement in neonates with perinatal asphyxia not only complicates perinatal management but also contributes to increased mortality.AIM To assess cardiac troponin T(cTnT)levels in asphyxiated neonates and their correlation with echocardiography findings,inotrope requirement,hypoxicischemic encephalopathy(HIE)stages,and mortality.METHODS cTnT levels,echocardiographic findings,the requirement of inotropes,HIE stages,and outcome were studied in neonates of gestational age≥34 wk with perinatal asphyxia.RESULTS Among 57 neonates with perinatal asphyxia,male gender,cesarean section,forceps/vacuum-assisted vaginal delivery and late preterm included 33(57.9%),23(40.4%),3(5.3%),and 12(21.1%)respectively.The mean gestational age was 38.4 wk(1.6 wk).HIE stages I,II,and III were observed in 7(12.3%),37(64.9%),and 9(15.8%)neonates respectively.26(45.6%)neonates had echocardiographic changes and 19(33.3%)required inotropes.cTnT levels were elevated in 41(71.9%)neonates[median(IQR);0.285(0.211-0.422)ng/mL].The Median cTnT level showed an increasing trend with increasing changes in echocardiography(P=0.002).Two neonates with mitral regurgitation and global hypokinesia had the highest cTnT levels(1.99 and 0.651 ng/mL).Of 31 neonates with normal echocardiography,18(58.06%)showed elevated cTnT.cTnT levels were significantly higher in those who required inotropic support than those who did not(P=0.007).Neonates with HIE stage III had significantly higher cTnT levels compared to those with HIE stage I/II(P=0.013).Survivors had lower median cTnT levels[0.210(0.122-0.316)ng/mL]than who succumbed[0.597(0.356-1.146)ng/mL].CONCLUSION cTnT levels suggestive of cardiac involvement were observed in 71.9%of asphyxiated neonates.cTnT levels correlated with echocardiography findings,inotrope requirement,HIE stages,and mortality.

Comparison of serum cardiac troponin-Ⅰ and creatine kinase MB isoenzyme concentrations in asphyxiated neonates

Objective:To assess the correlation of signs of myocardial damage to serum cardiac troponin I(cTnI)and creatine kinase MB isoenzyme(CK-MB)concentrations.Methods:Blood samples were collected from 25 term asphyxiated neonates and 25 controls at 12 h of age by immunoassay.The asphyxiated neonates were followed up until discharge or death.Results:Asphyxiated neonates had significantly higher concentrations of cTnI and CK-MB than controls(P<0.001).Serum cTnI concentrations were significantly higher in asphyxiated neonates who developed hypotension,heart failure or those had low ejection fraction(P<0.01).Serum cTnI concentrations were significantly higher in asphyxiated who died than those who survived(P<0.01).There was no significant difference in serum CK-MB mass concentrations between asphyxiated neonates with and without these complications.Conclusion:Unlike CK-MB,serum cTnI concentrations are significantly higher in asphyxiated neonates who died or developed cardiac dysfunction.

Prognostic value of N-terminal pro B-type natriuretic peptide and troponin Ⅰ in children with dengue shock syndrome

Objective:To investigate the contribution of N-terminal pro B-type natriuretic peptide(NT-pro BNP)and troponin Ⅰ to mortality in children with dengue shock syndrome.Methods:A longitudinal study was conducted on children with dengue shock syndrome in a hospital in southern Vietnam.Detailed clinical histories,physical examinations,and laboratory parameters,including NT-pro BNP and troponin Ⅰ,were recorded.A comparison between survival and non-survival was carried out to identify factors influencing mortality.Results:A total of 107 patients with a median age of 9 years were included in the study.Among them,63.6%(68/107)presented with compensated shock,36.4%(39/107)had hypotensive shock,23.4%(25/107)required mechanical ventilation,and 12.1%(13/107)died.The NT-pro BNP levels were 3.9 pmol/L(IQR:1.9,10.3)and 15.2 pmol/L(5.8,46.3),while the median high sensitivity troponin Ⅰ levels were 20 pg/L(6,95)and 62 pg/L(12,325)at the first and second measurements,respectively.The mortality group exhibited higher rates of hypotensive shock,prolonged shock,lactate levels,liver damage,NT-pro BNP,and troponin Ⅰ levels.Hypotensive shock(OR 12.96,95%CI 2.70-62.30,P=0.004),prolonged shock(OR 39.40,95%CI 6.68-232.70,P<0.001),AST>1000 IU/L(OR 9.50,95%CI 2.63-34.34,P=0.041),and NT-pro BNP>7 pmol/L(OR 44.40,95%CI 5.44-362.20,P=0.001)were identified as predictive factors for mortality in dengue shock syndrome.Conclusions:The NT-pro BNP level could serve as a potential biomarker for predicting mortality in children with dengue shock syndrome.

BUN/Cr、cTnⅠ、NT-proBNP在不同严重程度的急性左心衰竭患者中的诊断价值

目的:评估血尿素氮/肌酐比(blood urea nitrogen/creatinine ratio,BUN/Cr)、心肌肌钙蛋白Ⅰ(cardiac troponinⅠ,cTnⅠ)和N末端B型利钠肽原(NT-proBNP)在诊断急性左心衰竭患者的严重程度方面的有效性。方法:选取连云港市第二人民医院检验科2023年1月—2024年2月接收的122份急性左心衰竭患者的血清样本作为研究样本,根据急性生理学及慢性健康状况评分Ⅱ(APACHEⅡ)将患者分为轻症组(APACHEⅡ评分≤20分,45例)、重症组(APACHEⅡ评分21~30分,42例)及极重症组(APACHEⅡ评分≥31分,35例)。比较三组患者的血清BUN/Cr、cTnⅠ及NT-proBNP水平,采用Spearman分析评估血清BUN/Cr、cTnⅠ及NT-proBNP水平与急性左心衰竭患者严重程度的相关性,并构建受试者操作特征(ROC)曲线分析血清BUN/Cr、cTnⅠ及NT-proBNP水平对极重症急性左心衰竭患者的诊断价值。结果:极重症组的血清BUN/Cr、cTnⅠ及NT-proBNP水平均高于重症组、轻症组,且重症组均高于轻症组,差异均有统计学意义(P<0.05);相关性分析结果显示,血清BUN/Cr、cTnⅠ及NT-proBNP水平与急性左心衰竭患者的严重程度呈正相关(P<0.05);ROC曲线分析结果显示,血清BUN/Cr、cTnⅠ及NT-proBNP联合检测的敏感度、特异度分别为94.3%、90.8%,ROC曲线下面积(AUC)为0.969,优于单独检测。结论:在急性左心衰竭患者中,血清BUN/Cr、cTnⅠ及NT-proBNP的水平与疾病严重程度相关,联合检测可以有效诊断急性左心衰竭患者的疾病严重程度,具有较高的敏感度和特异度。

人心肌肌钙蛋白I-C融合蛋白在大肠杆菌中的可溶性表达及纯化

提取人心肌组织总RNA,RT PCR扩增出人心肌肌钙蛋白I(cardiactroponinI,cTnI)和肌钙蛋白C(TnC)基因,利用人工合成的可编码 19个中性氨基酸残基为主的DNA序列(Linker),将cTnI和TnC基因连接,插入到质粒pET15b中,将鉴定正确的重组pET15b质粒转化入大肠杆菌BL2 1(DE3)pLysS中,用异丙基 β D$C硫代半乳糖苷(IPTG)诱导蛋白质表达.结果在大肠杆菌中成功实现了全长cTnI C融合蛋白(cTnI linker TnC)的稳定可溶性高表达,在摇瓶中表达量可达 2 1mg/L.利用目的蛋白N端的组氨酸 标签"(His tag),经一步Ni2 + Sepharose柱亲和层析纯化,得到了聚丙烯酰胺凝胶电泳(PAGE)纯蛋白质.经初步研究,cTnI C具有较好的免疫原性和稳定性,有望成为cTnI测定系统可溯源的候选参考物质。

不同抗原表位的cTnⅠ单克隆抗体对cTnⅠ-TnC复合物亲和性的研究

目的:了解不同心肌肌钙蛋白Ⅰ(cTnⅠ)抗原表位的单克隆抗体(MAb)对cTnⅠ-肌钙蛋白C(cTnⅠ-TnC)抗原的亲和性,筛选新型cTnⅠ特异性抗体用于临床检测试剂盒研发。方法:基于微阵列化学发光免疫分析技术平台,采用cTnⅠ-TnC抗原点样硬基质芯片,以鼠源性cTnⅠMAb为待检抗体,HRP-羊抗鼠IgG为检测抗体,对抗原点样液、抗原点样浓度、待检抗体浓度进行实验条件优化;采用竞争法检测不同抗原表位的cTnⅠMAb对cTnⅠ-TnC的亲和力,实验组为加入梯度浓度的cTnⅠ-TnC,对照组加入等体积稀释液,检测不同cTnⅠMAb的反应信号,计算亲和常数。结果:最优实验条件:抗原点样液为P105,抗原点样浓度为0.1 mg/ml,待检抗体浓度为80 ng/ml;包含TnC抗体的20c6cc和7B9cc MAb亲和性最好,其中20c6cc MAb达3.18×10^(6) L/mol;cTnⅠMAb中位于肽链C端的a.a.r 130~145、169~178和190~196区域的cTnⅠMAb表现出较好的亲和力,其中MAb 625(a.a.r 169~178)为6.37×10^(5) L/mol,在cTnⅠMAb中亲和性最强。结论:cTnⅠ肽链C端a.a.r 130~145、169~178、190~196和TnC区的MAb与cTnⅠ-TnC抗原的亲和性较好,针对该区域设计新型cTnⅠ补位抗体,可作为解决自身抗体及肽链蛋白水解负性干扰的新思路。

慢性心力衰竭患者心脏彩超参数、血浆cMyBP-C水平变化及临床意义研究

目的探讨慢性心力衰竭(CHF)患者心脏彩超参数、血浆心脏型肌球蛋白结合蛋白-C(cMyBP-C)水平变化及临床意义。方法选择2021年3月至2023年2月该院收治的100例CHF患者作为CHF组,选择同期在该院体检的体检健康者100例作为对照组。CHF患者纽约心脏病协会(NYHA)心功能分级Ⅱ级57例,Ⅲ+Ⅳ级43例。所有研究对象均进行心脏彩超检查,比较两组左心室射血分数(LVEF)、左心房内径(LAD)、左心室舒张末期内径(LVEDD);两组均采用酶联免疫吸附试验检测血浆cMyBP-C水平,以及检测两组血清N末端B型脑钠肽前体(NT-proBNP)、脑利尿钠肽(BNP)和心肌肌钙蛋白I(cTnI)水平,以血清NT-proBNP、BNP和cTnI联合检测结果作为诊断CHF的金标准。绘制受试者工作特征(ROC)曲线分析LVEF、LAD、LVEDD、血浆cMyBP-C及血清NT-proBNP、BNP、cTnI对CHF的诊断效能。结果CHF组LAD、LVEDD均大于对照组,血浆cMyBP-C水平高于对照组,LVEF低于对照组,差异均有统计学意义(P<0.05)。Ⅲ+Ⅳ级CHF患者的LAD、LVEDD均大于Ⅱ级患者,血浆cMyBP-C水平高于Ⅱ级患者,LVEF低于Ⅱ级患者,差异均有统计学意义(P<0.05)。CHF组血清NT-proBNP、BNP和cTnI水平均明显高于对照组,差异均有统计学意义(P<0.05)。ROC曲线分析显示:LVEF、LAD、LVEDD、血浆cMyBP-C单独及LVEF+LAD+LVEDD+血浆cMyBP-C诊断CHF的AUC分别为0.741(95%CI:0.674~0.800)、0.679(95%CI:0.609~0.743)、0.797(95%CI:0.734~0.850)、0.836(95%CI:0.777~0.884)及0.934(95%CI:0.890~0.964),LVEF+LAD+LVEDD+血浆cMyBP-C诊断的AUC明显大于于LVEF、LAD、LVEDD、血浆cMyBP-C单独诊断的AUC(Z=2.833、3.922、2.057、2.679,P=0.005、0.001、0.040、0.007)。血清NT-proBNP+BNP+cTnI诊断CHF的AUC与LVEF+LAD+LVEDD+血浆cMyBP-C诊断CHF的AUC相比,差异无统计学意义(Z=0.354,P=0.723)。结论LVEF、LAD、LVEDD和血浆cMyBP-C 4项联合对CHF具有较高的诊断价值,且LVEF、LAD、LVEDD和血浆cMyBP-C 4项联合诊断CHF的效能与血清NT-proBNP、BNP、cTnI 3项联合诊断CHF的效能相当,可作为临床诊断CHF的新型指标。

cTnI、CTGF、AngⅡ和miR-21在老年性慢性心力衰竭肺部感染中的诊断价值

目的探讨心肌肌钙蛋白I(cTnI)、结缔组织生长因子(CTGF)、血管紧张素Ⅱ(AngⅡ)和微小核糖核酸-21(miR-21)在老年性慢性心力衰竭肺部感染中的诊断价值。方法选取郑州市金水区总医院2022年1月至2023年8月收治的70例老年性慢性心衰肺部感染患者作为合并感染组,同期70例老年单纯心衰患者作为单纯心衰组,以及同期70例老年健康体检者作为对照组。比较三组研究对象临床指标及cTnI、CTGF、AngⅡ、miR-21水平,比较合并感染组不同心功能分级cTnI、CTGF、AngⅡ、miR-21水平,分析老年性慢性心衰肺部感染与cTnI、CTGF、AngⅡ、miR-21相关性。结果合并感染组血清cTnI、CTGF、AngⅡ、miR-21均高于单纯心衰组和对照组,单纯心衰组高于对照组,差异有统计学意义(P<0.05);合并感染组心功能Ⅳ级患者血清cTnI、CTGF、AngⅡ、miR-21高于Ⅲ级和Ⅱ级,Ⅲ级高于Ⅱ级,差异有统计学意义(P<0.05);血清cTnI、CTGF、AngⅡ、miR-21均为老年性慢性心衰肺部感染的独立危险因素(P<0.05);Pearson相关性分析显示,老年性慢性心衰肺部感染与血清cTnI、CTGF、AngⅡ、miR-21水平呈正相关关系(r=0.566、0.543、0.555、0.582,P<0.05)。结论老年性慢性心力衰竭肺部感染患者多伴有血清cTnI、CTGF、AngⅡ、miR-21升高,cTnI、CTGF、AngⅡ、miR-21与老年性慢性心衰肺部感染存在相关性。