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荧光免疫法与免疫层析法检测血清N末端脑钠肽前体的方法学比较及偏倚评估作者：王卓周言言王雅琳佟凤芝来源：《医学信息》2016年第20期摘要：目的通过mini-VIDAS荧光免疫分析仪和Roche cobas h 232心脏标志物检测仪测定N末端脑钠肽前体的方法比对，探讨两种方法检测结果的偏差是否在允许的范围内，检测结果是否具有可比性。
方法以mini-VIDAS荧光免疫分析仪作为参考仪器，Roche cobas h 232心脏标志物检测仪作为实验仪器，依据美国临床和实验室标准化协会（CLSI）EP9-A2文件的要求设计比对方案，以采集自临床患者的空腹新鲜血清标本作为待测标本，以美国临床实验室修正法规1988（CLIA，88）允许总误差的1/2作为标准，对2台仪器检测结果间偏差进行评估。
结果荧光免疫法与免疫层析法比较，r2>0.95，2台仪器的相关性好，在医学决定水平x=300，x=450，x=900时，免疫层析法的预期相对偏倚分别是29.75%，18.47%，7.18%，在x=300，两种方法存在统计学差异，偏倚不可被临床接受。
结论临床实验室内同一检测项目同时在两套系统检测时，应进行比对实验和偏倚评估，以确保检测结果具有可比性。
关键词：N末端脑钠肽前体；方法比对；偏倚评估N末端脑钠肽前体（NT-proBNP）作为一种良好的心脏标志物，在心血管领域应用广泛，特别对急诊呼吸困难患者鉴别原因具有重要意义。
快速免疫分析仪在急诊检验工作中具有无法比拟的优越性，但也必须满足快速、准确、精密等要求[1]。
为确保快速分析仪的性能，医学实验室认可国家标准ISO15189要求检测系统在工作前进行分析评价，证实其能够满足预期用途[2]。
方法学不同的检测系统间在测定患者样品结果上具有可比性，在临床检验工作中是很重要的。
本实验按照临床实验室管理要求和美国临床实验室标准化协会（CLSI）EP9-A2文件的要求[3]，对两台仪器检测NT-proBNP的结果进行比对分析，并判断其临床可接受性，旨在为不同检测仪检测结果的可比性提供依据。
cobas liat pcr原理一、cobas liat系统简介1. cobas liat系统是罗氏诊断公司研发的一种新型核酸检测评台，旨在快速、准确地进行临床诊断。
2. 该系统采用了实时聚合酶链式反应（PCR）技术，能够对各种病原体进行检测，包括病毒、细菌和真菌等。
3. cobas liat系统的最大特点是可以在30分钟内完成一次检测，大大缩短了临床诊断的时间。
二、PCR技术原理1. PCR技术是一种能够放大DNA片段的生物技术方法，主要包括三个步骤：变性、引物结合和延伸。
2. 变性步骤：将DNA双链分解成两条单链。
3. 引物结合步骤：引物与目标DNA序列特异性结合。
4. 延伸步骤：通过DNA聚合酶酶活性，使引物延伸合成新的DNA链。
三、cobas liat系统PCR技术应用1. cobas liat系统采用实时PCR技术，可以同时进行变性、引物结合和延伸步骤，并实时监测PCR产物。
2. 采用荧光探针技术，将目标DNA序列与荧光探针结合，当PCR产物逐渐累积时，荧光信号强度也会增加。
3. cobas liat系统通过检测荧光信号强度，可以定量测定目标DNA序列的含量，从而快速准确地得出检测结果。
四、cobas liat系统的优势1. 高灵敏度：cobas liat系统可以检测非常低浓度的病原体DNA，因此对病原体的检测具有高度的灵敏度和准确性。
2. 快速性：cobas liat系统可以在30分钟内完成一次检测，大大缩短了临床诊断的时间，为临床医生提供了更快捷、更及时的诊断信息。
3. 多重检测：cobas liat系统可以同时对多种病原体进行检测，满足了临床上对同时检测多种病原体的需求。
五、结语通过以上对cobas liat系统PCR技术原理及其应用的介绍，我们可以看到，该系统在临床诊断中具有巨大的优势，为医生提供了一个快速、准确的临床诊断工具。
随着医学技术的不断进步，相信cobas liat系统在未来会有更广泛的应用，为临床医生带来更多的帮助和便利。
罗氏cobas h232操作指南IQC测试条用途：IQC测试条用于cobas h232仪器光学检测系统的核准。
摘要：IQC测试条包含两根可反复使用的控制测试条，用于确保仪器的正常工作。
IQC低值测试条用于检测范围低值的检查；IQC 高值则确保相应高值检测范围的准确。
因此，宜每日进行光学系统的核准。
Cobas h232 必须根据当地或国家相关规定使用罗氏CARDIAC IQC测试条进行核准。
测试条活性成分：金标抗-HSA抗体IQC低值：85ngIQC高值：126ng批号:每个包装的测试条均包含批特异的编码芯片。
仪器会提示用户插入芯片。
可以对仪器提示插入的编号和编码芯片上的编号进行比对，以确保编码芯片与测试条批号匹配。
如果芯片不匹配，仪器将显示错误信息。
注意事项：-供体外诊断使用-使用日常防护工具-根据当地守则合理处理废弃物-请勿触摸或擦拭测试条信号线区域-请勿加入任何样品至测试条上-注意避光，避免太阳光直射-测试完毕后立即将试纸条取出，并迅速放入IQC盒中，盖盖，避免灰尘和潮湿。
IQC操作步骤：将测试条从袋中取出至室温。
1)将IQC盒放置到室温2)开机3)取出相应的IQC试纸条，立即将除湿盖盖好4)按下QC Test键5)仪器提示插入IQC试纸条，插入IQC试纸条6)仪器提示插入IQC芯片，插入IQC芯片，选择测试水平，耐心等待结果显示（20秒）。
7)在倒计时结束时，在窗口显示结果。
结果将传入打印机（可选件）。
8)测试完毕后将试纸条取出，迅速放入IQC盒中，盖盖。
储存与稳定性：有效期内请储藏于2-30 ℃开封： 6 个月建议记录开启时间结果的显示：在反应倒计时结束时（20秒），仪器的窗口将显示Pass/ Fail。
“Pass”表明仪器光学系统工作正常。
“Fail”则说明，测量值超出可信范围。
当测量值超出可信范围时：-使用同一盒中的另一IQC测试条重复测量一次。
-如果第二根测试条测量值位于可信范围内，说明第一根测试条失效，不宜再次使用。
荧光免疫法与免疫层析法检测血清N末端脑钠肽前体的方法学比较及偏倚评估目的通过mini-VIDAS荧光免疫分析仪和Roche cobas h 232心脏标志物检测仪测定N末端脑钠肽前体的方法比对，探讨两种方法检测结果的偏差是否在允许的范围内，检测结果是否具有可比性。
方法以mini-VIDAS荧光免疫分析仪作为参考仪器，Roche cobas h 232心脏标志物检测仪作为实验仪器，依据美国临床和实验室标准化协会（CLSI）EP9-A2文件的要求设计比对方案，以采集自临床患者的空腹新鲜血清标本作为待测标本，以美国临床实验室修正法规1988（CLIA，88）允许总误差的1/2作为标准，对2台仪器检测结果间偏差进行评估。
结果荧光免疫法与免疫层析法比较，r2>0.95，2台仪器的相关性好，在医学决定水平x=300，x=450，x=900时，免疫层析法的预期相对偏倚分别是29.75%，18.47%，7.18%，在x=300，两种方法存在统计学差异，偏倚不可被临床接受。
结论临床实验室内同一检测项目同时在两套系统检测时，应进行比对实验和偏倚评估，以确保检测结果具有可比性。
标签：N末端脑钠肽前体；方法比对；偏倚评估N末端脑钠肽前体（NT-proBNP）作为一种良好的心脏标志物，在心血管领域应用广泛，特别对急诊呼吸困难患者鉴别原因具有重要意义。
快速免疫分析仪在急诊检验工作中具有无法比拟的优越性，但也必须满足快速、准确、精密等要求[1]。
为确保快速分析仪的性能，医学实验室认可国家标准ISO15189要求检测系统在工作前进行分析评价，证实其能够满足预期用途[2]。
方法学不同的检测系统间在测定患者样品结果上具有可比性，在临床检验工作中是很重要的。
本实验按照临床实验室管理要求和美国临床实验室标准化协会（CLSI）EP9-A2文件的要求[3]，对两台仪器检测NT-proBNP的结果进行比对分析，并判断其临床可接受性，旨在为不同检测仪检测结果的可比性提供依据。
cobas h 232systemWhen on the spot cardiac decisionsneed on the spot results in Primary Carecobas cardioIs there a better pathway?Without Point of Care (POC) testingWith POC testingPatient presentsAppropriate action takenPOC test in only 12 minutesThe path of least resistanceBy providing rapid, accurate results near the patient, POC testing speeds up diagnosisand treatment, improving clinical outcomes and ensuring patients are managedefficiently and more cost-effectively.“Practices should put in place models of care so that theyuse a systematic approach for…identifying people at highrisk of CHD…(and) offering regular review to people athigh risk of CHD.”National Service Framework– Coronary Heart DiseasePractice managementResults are available within minutes, helping to improve efficiencyAppropriate treatment can be given without delayHospital referrals can be reserved for patients who really need it1–3Patient outcomesRapid diagnosis allows appropriate treatment to be initiated by GP’sEarly diagnosis and treatment reassures patients and reduces anxiety associatedwith uncertaintyCost-effectivenessEarly therapeutic initiation and regular monitoring can help reduce complicationsand improve cost-efficiency4Avoiding unnecessary referrals to Secondary Care will save the practice moneycobas cardioIntroducing thenew cobas h 232systemDesigned for on the spot cardiac decisionsEase of use•Insert strip, apply sample, read result•Intuitive touch-screen •No maintenance •Easy to cleanConnectivity•Results transmitted via IR to printer or Base Unit•In combination with cobas IT 1000 data management solution, reduces effort for documentation and fulfilment of quality assurance requirementsSpeed•Results available in 8–12minutes•Rapid, on-the-spot decision support for treatment, referral, or discharge of cardiovascular patientsReliability•On board QC•External QC through the provision of EQA ampoules •Results comparable to Roche laboratory methods 5–8•Quality assurance via patient identification and QC operator lock-outPortability•Portable device which is suitable for use in the GP’s surgery, one stop clinics orcommunity hospitalscobas cardio04877802190048778451900487777219004877799 19004877900 190cobas h 232– when you need to be sure3 simple steps to quick resultsSlide in test stripApply sample (150 µL heparinized whole blood)Result appears on screen within minutes123* At the 99th percentile of a reference population**Roche CARDIAC M for use on the cobas h 232system will be available in the course of Q3/2007D-dimerD-dimer is a specific fragment of cross-linked fibrin that circulates in the blood stream for several days following a thrombotic event, such as DVT. Patients at high risk of DVT include those receiving high dose oestrogen therapy, those who have previous history of DVT, post surgical and limited mobility.9D-dimer is produced naturally as part of the wound healing process, but can be found in higher quantities in the blood in abnormal clotting processes, as with thrombosis or embolism. When clots are formed at the wrong time and place as a result ofunderlying diseases, the presence of D-dimer indicates the occurrence of unwanted thrombotic events.Diagnostic value of D-dimer:D-dimer is a valuable marker to rule out suspected DVT and PE10,11Used as first diagnostic step, the determination of D-dimer helps to avoid unnecessaryand expensive examinations and therapeutic interventions–D-dimer based protocols can reduce treatment costs by avoiding the use of expensive imaging techniques12NT-proBNPBNP is synthesized as the prohormone proBNP and is released from the myocardiuminto the circulation upon myocardial stress. After stimulation of heart muscle cells,proBNP is cleaved by a protease into N-terminal proBNP(NT-proBNP) and thebiologically active hormone BNP. The biological half-life of NT-proBNP is60–120 minutes (BNP is only 20 minutes).Diagnostic value of NT-proBNP:High negative predictive value (> 97%) enables exclusion of heart failure in symptomaticpatients, allowing appropriate action to be taken13Helps to confirm the presence of heart failure, giving confidence to begin appropriatetreatment soonerAn alternative assessment to Echo, reducing pressure on waiting lists14,15Sensitive test enables diagnosis of systolic and diastolic ventricular dysfunction,even in mild and asymptomatic cases of heart failure16Allows for risk stratification and assessment of prognosis across a wide rangeof cardiovascular diseases17Cost savings by optimising resources18and decreasing the need for other diagnostic tests19 Diagnostic value of NT-proBNP:cobas cardioTroponin TCardiac troponin T is the most specific, and sensitive, biochemical marker of myocardial necrosis. A positive test result clearly establishes the diagnosis of myocardial infarction, even if symptoms or electrographic changes are ambiguous or not present.Diagnostic value of troponin T:Most appropriate cardiac marker and criterion to define acute myocardial infarction,according to the ESC/ACC recommendations21,22Can detect non-ST segment infarctions in patients presenting with acute coronary syndromeLarge window of detection (2hours up to 14 days) – an infarction can be confirmed in patientsthat report complaints only, after one or two weeksMyoglobinMyoglobin, a non cardiac specific protein in the cytoplasm of striated muscles,is rapidly released from the cells after muscle damage. Determination of myoglobincovers the early phase of myocardial infarction diagnosis since it is the first and themost sensitive biochemical marker that can be detected in the blood.Myoglobin increases as early as 1to 2hours after the onset of chest pain. However,since elevated myoglobin is not specific for damage of the heart muscle, a troponin T test must be performed to confirm the diagnosis of myocardial infarction. Myocardial infarction is ruled out if myoglobin is not detected within 6 hoursafter onset of symptoms.23Diagnostic value of myoglobin:Earliest marker to appear< 2hours post-infarctionUseful when the patient presents to physician very soon after onset of symptoms24CK-MBCreatine kinase (CK) is an enzyme that mainly occurs in muscles, heart and brain.It is divided into three different forms: CK-MM (muscle type), CK-MB (heart-type)and CK-BB (brain-type). Total CK thus only offers limited specificity. In myocardialdamage, such as in acute myocardial infarction, cardiac specific CK-MB is releasedfrom destroyed myocardial cells.An increase of CK-MB activity in the blood can be detected as early as 2–3 hoursafter the infarction. CK-MB activity reaches its peak after12–24 hours and returnsto the reference range usually after2–3 days.Diagnostic value of CK-MB:Diagnosis of ACS and myocardial infarctionCK-MB and troponin T have identical intended uses except that, dueto the different kinetics with a shorter half-life (peak within 24 hours),CK-MB can be used for reinfarction assessment–CK-MB is indicative for reinfarction if level does not return to normalwithin approx. 2–3 days from peak, whereas troponin T is still elevated1Can be used in combination with myoglobin and troponin T–for a complete assessment of cardiac markers–to allow alignment with existing protocols–when specifically indicated by the patient's circumstancescobas cardioUseful informationWebsitesNICE – National Institute for Clinical Excellence/SIGN – Scottish Intercollegiate Guidelines Network/DoH Publications and Statistics/PublicationsAndStatistics/Publications/Publications PolicyAndGuidance/DH 4094275Cardiology Pathway/public/Practice Based Commissioning/assetRoot/04/13/13/97/04131397.pdfHealth Improvement Programme/Health Improvement ProgrammeMaterial order numbers:References1.Wu A, et al. National Academy of Clinical Biochemistry Standards of Laboratory Practice: Recommendations for theUse of Cardiac Markers in Coronary Artery Diseases. Clin Chem1999; 45: 1104–1121.2.Oudega R, Moons KG, Hoes AW. Ruling out deep venous thrombosis in primary care. A simple diagnostic algorithmincluding D-dimer testing. Thromb Haemost2005; 94: 200–205.3.Campbell PM, Radensky PW, Denham CR. Economic analysis of systematic anticoagulation management vs. routinemedical care for patients on oral warfarin therapy. Dis Manag Clin Outcomes2000; 2: 1–8.4.Horstkotte D, Piper C, Wiemer M. Optimal Frequency of Patient Monitoring and Intensity of Oral Anticoagulation Therapyin Valvular Heart Disease. J Thromb Thrombolysis1998; 5 Suppl 1: 19–24.5.Zugck C et al. Multicentre evaluation of a new point-of-care test for the determination of NT-proBNP in whole blood.Clin Chem Lab Med2006; 44(10): 1269–1277.6.Dempfle CE et al on behalf of the CARDIM study group. Sensitivity and specificity of a quantitative point of careD-dimer assay using heparinised whole blood, in patients with clinically suspected deep vein thrombosis.Thromb Haemost2006; 95: 79–83.7.Derhaschnig U et al for the CARMYT Multicentre Study Group. Diagnostic efficiency of a point-of-care system forquantitative determination of troponin T and myoglobin in the coronary care unit. Point of Care2004; 3(4): 162–164.8.Schwab M et al. "Evaluation Report: System Performance of the cobas h 232system" (/cobas-h232.html].9.Thromboembolic Risk Factors (THRIFT) Consensus Group. Risk of and prophylaxis for venous thromboembolism inhospital patients. BMJ1992; 305: 567–574.10.Brown M, et al. An emergency department guideline for the diagnosis of pulmonary embolism: an outcome study.Acad Emerg Med2005; 12: 20–25.11.Diamond S, et al. Use of D-dimer to aid in excluding deep venous thrombosis in ambulatory patients.Am J Surg2005; 189: 23–26.12.Perrier A, et al. Cost-effectiveness analysis of diagnostic strategies for suspected pulmonary embolism including helicalcomputed tomography. Am J Respir Crit Care Med2003; 167: 39–44.13.Hobbs FO, et al. Reliability of N-terminal pro-brain natriuretic peptide assay in diagnosis of heart failure:cohort study in representative and high risk community populations. BMJ2002; 324: 1498.14.Quality and Outcomes Framework(QOF). /assetRoot/04/07/86/59/04078659.pdf15.SIGN. Scottish Intercollegiate Guidelines Network. /guidelines/published/index.html16.Hobbs FO, et al. Reliability of N-terminal proBNP assay in diagnosis of left ventricular systolic dysfunction withinrepresentative and high risk populations. Heart2004; 90: 866–870.17.Mockel M, et al. Role of N-terminal pro-B-type natriuretic peptide in risk stratification in patients presentingin the emergency room. Clin Chem2005; 51: 1624–1631.18.Siebert U, et al. Cost-effectiveness of using N-terminal pro-brain natriuretic peptide to guide the diagnostic assessmentand management of dyspneic patients in the emergency department. Am J Cardiol2006; 98: 800–805.19.Nielsen LS, et al. N-terminal pro-brain natriuretic peptide for discriminating between cardiac and non cardiac dyspnea.Eur J Heart Fail2004; 6: 63–70.20.BNP Experience in southern Derbyshire, Martin Cassidy. /content/showcontent.aspx?contentid=884.21.Alpert J, et al. Myocardial infarction redefined-a consensus document of The Joint European Societyof Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction.J Am Coll Cardiol2000; 36: 959–969.22.Pollack C, et al. 2002update to the ACC/AHA guidelines for the management of patients with unstable anginaand non-ST-segment elevation myocardial infarction: implications for emergency department practice.Ann Emerg Med2003; 41: 355–369.23.de Winter R, et al. Value of myoglobin, troponin T, and CK-MBmass in ruling out an acute myocardial infarctionin the emergency room. Circulation1995; 92: 3401–3407.24.Mockel M, et al. Validation of NACB and IFCC guidelines for the use of cardiac markers for early diagnosisand risk assessment in patients with acute coronary syndromes. Clin Chim Acta2001; 303: 167–179.cobas cardioCOBAS, LIFE NEEDS ANSWERS, COBAS H, ROCHE CARDIAC are trademarks of Roche.© 2007Roche Diagnostics Roche Diagnostics Limited Charles AvneueBurgess Hill, RH15 9RY cobas cardio P M 1 9 1 0。
罗氏线圈传感器的测量原理罗氏线圈传感器由罗氏线圈和对其输出电压进行处理的放大积分电路组成。
1罗氏线圈设计基本原理罗氏线圈是一种空心环形的线圈，有柔性和硬性两种，可以直接套在被测量的导体上来测量交流电流。
其设计基本原理如图：罗氏线圈测量电流的理论依据是法拉第电磁感应定律和安培环路定律，当被测电流沿轴线通过罗氏线圈中心时，在环形绕组所包围的体积内产生相应变化的磁场，强度为H,由安培环路定律得：用dl=I(t)(1)由8=仙11,e(t)=d@/dt,0)=N/B•。
&(t)=Mdi/dt,得：其截面为矩形时，互感系数M和自感系数L分别为：M,0Nhln(b/a)/2九(2)L=^N2hln(b/a)/2九(3)上式中，H为线圈内部的磁场强度，B为线圈内部的磁感应强度，⑷为真空磁导率，N为线圈匝数，e(t)为线圈两端的感应电压，a,b分别为线圈横截面的内外径，h为截面高度。
由此可见，线圈一定时，M为定值，线圈的输出电压与di/dt成正比。
2放大积分电路设计原理若想准确还原测量的交流电流i,必须加一个反相积分电路。
因罗氏线圈感应出的电压很小，为了放大该感应电压，须在积分器前面加一放大电路。
积分是一个非常重要的环节，被还原的信号非常小，为方便测量，先将信号放大再积分这样一方面可以增大还原信号，另一方面，电容的存在可以过滤掉不必要的干扰网基本放大积分电路设计如图3:T0图3基本放大积分电路设计通过对罗氏线圈感应电压的放大和积分处理，可还原出所测量的交流电流。
那么，罗氏线圈的电阻，自感L,互感M及输出电压u i(t)已知，电路中电阻，电容，集成运放电路的参数应如何估计或计算呢？。
