CoagulationFactorAssay凝血因子检测WhydowemeasureFVIII为什么我们要做FVIII检测DiagnosisofHaemophiliaandVWD诊断血友病和VWDFactorVIIIConcentratepotency因子VIII浓缩剂的强度Post-Infusionrecoverysamples输注后恢复的标本Thrombophilia血栓PharmacokineticstudiesinHaemophilia血友病的药代动力学研究TheFactorVIIIAssayProblem因子VIII检测的问题NumberofpublishedstudiesshowingFVIIIlevelsinpost-infusionsamplestobe20-50%higherwhenmeasuredbychromogenicasopposedto1-stageassay.一些已发表的研究显示,用显色法检测输注后样本的因子VIII水平要比一期法检测高20-50%Alsodifferencesinpharmacokineticdata药代动力学的数据也存在差异MostpronouncedinBDD-rFVIII(Refacto)最明显的是BDD-rFVIIIClinicalRamifications临床后果Undertreatment(riskofbleeding)缺乏治疗(出血风险)Overtreatment(cost)过度治疗(花费)Standardisationofresultsbetweendifferentlaboratories.不同实验室之间结果标准化ClottingFactorAssays凝血因子检测Invitroassaysthatmeasurethecoagulantactivityoftheinactivecirculatingprotein(zymogen)byartificiallysimulatinginvivoactivationandthenmeasuringtheresponse.体外检测未活化的循环蛋白(酶原)的凝血活性可通过人工刺激其类似体内的活化,随后检测其反应。One-StageAssay一期法Two-StageAssay二期法ChromogenicAssay显色法One-StageFactorVIIIBioassay(一期法因子VIII生物学检测)BasedontheAPTTFirstdescribedbyLangdelletal1953BystudyingratiosofHaemAandNPthattheAPTTislinearlyrelatedtothelogarithmoftheFVIIIconcentration基于APTT检测。首次由Langdell等人在1953年发表。通过研究HaemA和NP比值,发现APTT与FVIII浓度的对数呈线性相关。CorrectionoftheAPTTofaplasmaseverelydeficientinfactorVIIIbyaddingdilutionsofStdortestplasma.通过在严重缺乏因子VIII的血浆中加入不同稀释度的标准或测试血浆稀释液,纠正其APTTEqualvolumesofplasmadilutionandFactorVIII-deficientplasmaaremixedtogetherandanAPTTisperformedforeachmixture等体积混合血浆稀释液和乏因子VIII血浆,随后检测每个混合体的APTT。CoagulationtimesareinverselyproportionaltothefactorVIIIconcentration凝血时间与因子VIII的浓度成反比。Bioassays:Design生物学检测法:设计EnsuresthatStandardandTestpreparationsarecomparedunderidenticalconditions,takingintoaccountanyfactorswhichmayleadtobiasedpotencyestimates.确保标准样品和检测样品在相同条件下进行比较,考虑所有可能引起测试偏倚的因素Dilutionrange:Shouldcoverthelinearpartofdilutioncurveaswidelyaspossible稀释范围:应该尽可能宽地包括稀释曲线的线形部分Numberofdilutions:稀释度数量StandardCurve-Atleastthreedilutions(标准曲线-至少三个稀释度)Testcurve-atleasttwoandpreferablythreepoints(检测曲线-至少两个,最好三个点)ResponseLogDoseOne-StageFactorVIIIBioassayClottingTimeFactorVIIIConcentration(Log)TS100%25%One-StageFactorVIIIBioassayFactorVIIIConcentration(Log)ClottingTimeTS100%50%Non-parallelconverginglinessuggestthepresenceofaninhibitor非平行的相交线提示有抑制物的存在One-StageFactorVIIIBioassayFactorVIIIConcentration(Log)ClottingTimeTS100%50%Non-paralleldiverginglinessuggestsampleactivationortechnicalerror(非平行的分岔线提示样品被激活或技术误差)FIXassaydesignFIX检测设计100UKHaemophiliacentresUKNEQAS2003100个英国血友病中心•25%usedsingletestdilution,20%used2dilutions,25%用单测试稀释度,20%用2个稀释度•55%used3testdilutions55%用3个稀释度•32%usedastoredcalibrationcurve•32%用已存的校正曲线Factorassays-Why3testdilutions?为什么用3个测试稀释度FIXsupplementaryexercise2003TestdilutionsnMeanFIXU/dlCV%1226.354%2176.529%3426.023%Factor:V...