心肌肌钙蛋白I检测方法及其影响因素

心肌肌钙蛋白I（cTnI）是心肌损伤最特异、最敏感的血清标志特之一，目前已被广泛地应用于临床诊断。但cTnI检测方法尚未标准化，循环中cTnI浓度的检测也受血浆肝素浓度、类风湿因子水平、溶血指数、慢性肾脏衰竭、骨骼肌损伤、年龄等多种因素干扰，影响其在临床中更广泛的应用。     

心肌肌钙蛋白Ⅰ的检测方法及临床应用进展

随着心肌肌钙蛋白Ⅰ(cardiac troponin Ⅰ，cTnⅠ)测定方法的逐渐标准化、检测系统的相对固定及质控措施的不断完善，cTnⅠ作为心肌损伤最特异、最敏感的血清标志物之一，具有诊断窗口期宽、诊断阈值明确及检测快速等优点。在心肌缺血性损伤、心肌非缺血性损害的诊断及骨骼肌损伤的鉴别中得到广泛应用。正逐渐取代CK-MB成为判断心肌损伤，特别是诊断急性心肌梗死(acute myocardial infarction，AMI)的“金标准”。现就cTnⅠ的检测方法及临床应用进展进行综述。     

心肌损伤的早期诊断生化标志物心肌肌钙蛋白I

心肌肌钙蛋白 I(cardiac troponin I,c Tn I)是一项反映心肌损伤的最新诊断指标 ,c Tn I在血中出现早 ,持续时间长 ,且为心肌细胞所特有 [1 ,2 ] ,具有敏感性高、特异性强的特点 ,对心肌梗死 (acute myocardial infarction,AMI)、不稳定性心绞痛(unstable angina pectoris,U AP)、围手术期心肌损伤等疾病的诊断 ,病情监测及预后判断具有重要的临床应用价值。1　 c Tn I的结构及变化Tn I是肌钙蛋白复合体中的亚单位之一 ,参与钙离子诱导的肌肉收缩 ,心肌和骨骼肌快肌、慢肌中的肌钙蛋白是由不同的具有独特氨基酸序列的基因决定的 ,所…     

心肌肌钙蛋白I快速检测对急性心肌梗死诊断的临床应用

目的：探讨心肌肌钙蛋白I（cTnI）快速检测对急性心肌梗死（AMI）早期诊断和不良后果的预测价值。方法：对119例轻度可疑的AMI患者在发病后24h内检测cTnI和肌酸激酶同工酶MB（CK-MB）活性。结果：（1）在发病后6h、12h和24h内cTnI检测AMI的敏感性分别为37．8％、84．4％和95．2％，特异性为100．0％；（2）在发病后6h和24h内，CK-MB（活性）检测AMI的敏感性分别为70．0％和76．7％。结论：cTnI快速检测对诊断AMI具有高度的敏感性和特异性，并能预测患者的不良后果。     

肌钙蛋白T对心肌受损诊断的临床应用进展

肌钙蛋白Ｔ对心肌受损诊断的临床应用进展李守霞赵素彬赵瑞月赵瑞堂杨健英史广生肌钙蛋白Ｔ（ＴｒｏｐｏｉｎｉｎＴ．ＴｎＴ）是肌钙蛋白复合体（Ｔｎｃｏｍｐｌｅｘ）的一种多肽亚单位，是心肌收缩的一种调节蛋白，近年来临床研究非常活跃，对心肌梗死（ＡＭＩ）、不稳定...     

心肌肌钙蛋白I(cTnI)在心肌损伤诊断中的应用价值

目的探讨心肌肌钙蛋白I(cTnI)在诊断心肌损伤疾病中的价值。方法电化学发光法和酶法。结果心肌炎、心绞痛和心肌梗塞患者血清中cTnI、CK、CK-MB、CRP浓度升高明显,而正常对照组三项指标正常,两组比较有显著性差异(P<0.05)。结论在心肌损伤的实验室诊断指标中cTnI敏感性最高、特异性最强,有极其重要的诊断意义和疗效评价价值。     

心肌肌钙蛋白I检测对急性心肌梗死诊断临床应用价值

心肌肌钙蛋白Ⅰ(cTnI)是近年来发现的心脏损伤敏感性标志物,对心脏损伤具有高度特异性。本研究通过与心肌酶学检测进行比较,探讨其在急性心肌梗死中的诊断价值。1资料与方法1.1研究对象按世界卫生组织(WHO)制定的缺血性心脏病诊断标准,及冠脉造影确诊。收集2000年10月至2002年1     

心肌肌钙蛋白的临床应用和检测进展

上个世纪 90年代起 ,心肌肌钙蛋白 (ｃＴｎ)开始运用于临床诊断心肌损伤。由于其高度的特异性和较好的敏感性 ,很快为临床医生和检验人员所接受。随着广泛的临床实践 ,有关ｃＴｎ临床应用和检测的进展正在不断深入。一、ｃＴｎ的临床应用最初的ｃＴｎ应用报道主要集中于和ＣＫ ＭＢ等心肌酶标志物的临床应用比较 ,如在心肌梗死(ＭＩ)和心绞痛中的诊断、危险性估计和预后判断价值 ,ＭＩ后临床溶栓治疗效果判定。ｃＴｎ在心脏疾病诊断和治疗中的其他应用也随后陆续报道 ,如在诊断各种心肌损伤 (心肌炎、心肌创伤、心脏手术、围手术期心脏并发…     

心肌肌钙蛋白的临床应用和检测进展

上个世纪90年代起,心肌肌钙蛋白(cTn)开始运用于临床诊断心肌损伤.由于其高度的特异性和较好的敏感性,很快为临床医生和检验人员所接受.随着广泛的临床实践,有关cTn临床应用和检测的进展正在不断深入.     

循环心肌肌钙蛋白Ⅰ自身抗体的检测及临床意义

目的 了解急性心肌梗死(AMI)和心肌炎患者循环内抗心肌肌钙蛋白Ⅰ(cTnI)自身抗体的阳性率,促进临床实验室正确认识和了解这种特异性自身抗体对cTnI检测的负性干扰.方法 建立检测cTnI自身抗体的ELISA方法,在121例AMI和24例心肌炎患者血清中进行cTnI自身抗体的筛查;采用Western Blot对cTnl自身抗体阳性血清进一步验证;通过回收试验分析cTnI自身抗体对cTnI检测干扰的特异性.结果 121例AMI患者中有10.74%(13/121)cTnI自身抗体阳性,24例心肌炎患者中有8.3%(2/24)cTnl自身抗体阳性.将cTnI-C融合蛋白(cTnI终浓度为0.625-100ug/L)加入1例cTnI自身抗体阳性的血清中进行回收试验,各浓度cTnI均出现不同程度的低回收,并呈正相关(Spearman相关系数=0.943,P=0.005);而加入正常人血清中的cTnI回收率则没有明显的改变(Spearman相关系数=0.377,P=0.461).当加入终浓度为20ug/L的cTnI时,13份cTnI自身抗体阳性的AMI患者血清中有5份回收率<80%.结论 心肌损伤患者循环中存在cTnI自身抗体并非罕见,所产生的负性干扰足以使cTnI的检测结果失真,应在临床实验室引起高度重视.     

血清中心肌肌钙蛋白Ⅰ自身抗体的检测及临床意义

[目的]建立血清中心肌肌钙蛋白I（cTnI）自身抗体的ELISA检测方法,探讨其在冠心病诊断中的临床意义。[方法]采用间接ELISA方法,检测90例冠心病患者血清,其中急性心肌梗死（AMI）患者30例,不稳定性心绞痛（UA）患者30例,稳定性心绞痛（SA）患者30例,另健康对照者30例,进行比较和统计学分析。[结果]cTnI自身抗体阳性率在冠心病各组明显高于健康对照组,AMI组阳性率高于UA组,uA组高于SA组。[结论]cTnI自身抗体的出现与心肌损伤程度显示呈正相关,对病情严重程度的判定具有一定意义。     

The antibody configurations of cardiac troponin I assays may determine their clinical performance

BACKGROUND: Previous studies have shown superior clinical performance of the cardiac troponin I (cTnI) assay from Beckman-Coulter Diagnostics. This assay had a unique combination of monoclonal antibodies with 2 monoclonal antibodies directed against epitopes near the NH(2) terminus of the heart-specific region of troponin I. The approach has been adopted by the new cTnI assay from Abbott Diagnostics. The aim of our study was to investigate whether this approach affects the clinical performance of cTnI assays. METHODS: Cardiac troponin concentrations were measured in a random sample of patients with unstable coronary artery disease included in the GUSTO IV trial (n = 696) by the AccuTnI (Beckman-Coulter Diagnostics), Architect cTnI (Abbott Diagnostics), Immulite 2500 cTnI (Diagnostics Products Corporation), and Elecsys 2010 cTnT (Roche Diagnostics) assays and related to the 1-year mortality. The primary cutoff concentrations were based on the 99th percentile upper reference limits and an imprecision (CV) < or =10%. RESULTS: The sensitivities of the AccuTnI and Architect cTnI assays in identifying patients who died within 1 year were equal and were significantly higher (P <0.05) than those of the Immulite 2500 cTnI and the Elecsys cTnT assays. The concordance between the AccuTnI and Architect cTnI assays was 97%, but concordances between the Architect cTnI and the Elecsys cTnT assays were 89%-92% with more at-risk patients (P <0.01 to P <0.001) identified by the Architect cTnI assay. CONCLUSIONS: The Architect cTnI assay has clinical performance similar to that of the AccuTnI, probably as a result of the inclusion of a monoclonal antibody against troponin I epitope 41-49 in the assay.     

充血性心力衰竭患者血清肌钙蛋白T、肌钙蛋白Ⅰ检测及临床分析

目的研究充血性心力衰竭患者血清肌钙蛋白T(cTnT)和肌钙蛋白Ⅰ(cTnI)水平与心功能的关系及其对预后的判断。方法检测110例不同病因、不同心功能分级的充血性心力衰竭患者的cTnT、cTnI及左室射血分数(LVEF),并与40名健康对照组的结果进行比较。结果心功能Ⅱ级组cTnT为(78.56±25.65)pg/mL,cTnI为(0.85±0.57)ng/mL,LVEF值为57.46%±4.42%;心功能Ⅲ级分别为(249.25±76.21)pg/mL、(3.75±1.83)ng/mL、44.27%±10.13%;心功能Ⅳ级组分别为(375.62±81.29)pg/mL、(8.57±2.56)ng/mL、36.75%±5.66%,与健康对照组[分别为(3.65±0.96)pg/mL、(0.02±0.01)ng/mL、65.52%±8.01%]比较,差异有统计学意义(P<0.01),且心功能越差,cTnT、cTnI浓度越高;cTnT、cTnI与LVEF值均呈负相关,r分别为-0.487、-0.360,差异有统计学意义(P<0.01)。结论检测cTnT、cTnI对于判断充血性心力衰竭患者病情严重程度及预后具有重要的临床价值,是早期评估患者风险的重要方法。     

Analytical and clinical performance of two cardiac troponin I immunoassays.

Cardiac troponin I assays for Axsym (Abbott Diagnostics, Abbott Park, IL, USA) and Immuno 1 (Bayer Corporation, Tarrytown, NY, USA) analysers were evaluated. Heparin plasma or serum could be used for both assays. Samples were stable for 24 h at ambient temperature, 3 days at 4-8 degrees C and 3 months at -20 degrees C. After 10 months' storage at -80 degrees C, the recoveries were well above 100% by both assays. Total coefficients of variation for Axsym assay were 9.0%, 5.8% and 5.3% at concentrations of 2.6 microg/l, 9.83 microg/l and 34.3 microg/l respectively; for Immuno 1 these were 4.4 %, 1.6% and 1.8% at 2.3 microg/l, 6.27 microg/l and 44.35 microg/l respectively. It was > or =20% at concentration of < or =0.5 microg/l for Axysm assay and < or =0.15 microg/l for Immuno 1 assay. Recoveries were < or =90% at < or =0.22 microg/l on Axsym and at < or =1.47 microg/l on Immuno 1. Neither method showed significant interference with haemoglobin, bilirubin, triglycerides or rheumatoid factor. Correlation between the two methods was excellent (r = 0.997, Y (Axsym) = 4.2X (Immuno 1) +3.2). The highest concentrations detected in 50 healthy subjects were 0.3 microg/l and 0.1 microg/l by Axsym and Immuno 1 methods, respectively. Twelve out of 43 renal failure patients had troponin I 0.13-0.9 microg/l using Axsym method and 4 had levels of 0.07-0.13 microg/l using Immuno 1. In muscle trauma patients, troponin I was undetectable.     

重组人心肌肌钙蛋白I纯化方法的对比

目的：对比两种重组人心肌肌钙蛋白 I（rhcTnI）纯化方法,获取稳定的 rhcTnI,促进心肌肌钙蛋白（cTnI）诊断标准化的研究。方法超声破碎工程菌获取 rhcTnI 包涵体,经2％ Tritonx-100,2 mol/L 脲洗涤后溶解在8 mol/L 脲中,分别经 CM-FF 柱上复性和稀释复性纯化 rhcTnI,对比两种方法纯化 rhcTnI 的获得率及其产物在4、-20、-80℃及冻干条件下的稳定性,确立高效获取稳定的 cTnI 的纯化方法。结果0．1 g 湿重包涵体经 CM-FF 柱上复性和稀释复性的获得率分别为26．8％和18．9％。4、-20、-80℃及冻干条件下,CM-FF 下柱上复性获得的 rhcTnI 稳定,并且柱上复性纯化周期短,效率高。结论 CM-FF 柱上复性要比稀释复性纯化 rhcTnI 高效、稳定。     

Comparison of cardiac troponin T and troponin I assays--implications of analytical and biochemical differences on clinical performance

The usefulness of cardiac troponins for detection of myocardial cell necrosis and risk stratification has been established beyond doubt. Cardiac troponin testing is a key diagnostic element for the diagnosis and management of patients with acute coronary syndromes without ST segment elevation and is increasingly used in non-coronary diseases to indicate prognostically important cardiac damage. Given the biochemical and analytical differences of cTnT and cTnI there is ongoing controversy regarding the comparability and clinical performance of cTnT and cTnI. cTnT and cTnI are both expressed in cardiomyocytes but differ with respect to biochemical and analytical characteristics. While minor differences of analytical precision or biochemical properties are not relevant for diagnosis and management of patients with acute coronary syndromes and most diseases with non-coronary related elevations of cardiac troponins, these differences may be amplified in patients with chronic renal failure. In fact, recent studies in patients with end-stage renal disease under chronic hemodialysis have readdressed the issue whether cTnT and cTnI are really comparable. The present review will provide a state-of-the-art overview on the performance of cardiac troponins in acute coronary disease and other clinical conditions.     

Degradation of cardiac troponin I in serum complicates comparisons of cardiac troponin I assays.

BACKGROUND: Up to a 20-fold variation in serum cardiac troponin I (cTnI) concentration may be observed for a given patient sample with different analytical methods. Because more limited variation is seen for control materials and for purified cTnI, we explored the possibility that cTnI was present in altered forms in serum. METHODS: We used four recombinantly engineered cTnI fragments to study the regions of cTnI recognized by the Stratus(R), Opus(R), and ACCESS(R) immunoassays. The stability of these regions in serum was analyzed with Western blot. RESULTS: The measurement of several control materials and different forms of purified cTnI using selected commercial assays demonstrated five- to ninefold variation. Both the Stratus and Opus assays recognized the N-terminal portion (NTP) of cTnI, whereas the ACCESS assay recognized the C-terminal portion (CTP) of cTnI. Incubation of recombinant cTnI in normal human serum produced a marked decrease in cTnI concentration as determined with the ACCESS, but not the Stratus, immunoassay. Western blot analysis of the same samples using cTnI NTP- and CTP-specific antibodies demonstrated preferential degradation of the CTP of cTnI. CONCLUSIONS: The availability of serum cTnI epitopes is markedly affected by the extent of ligand degradation. The N-terminal half of the cTnI molecule was found to be the most stable region in human serum. Differential degradation of cTnI is a key factor in assay-to-assay variation.