凝血与血小板减少.ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Blood Coagulation Overview,and,Thrombophilia,Cliff Takemoto M.D.,Pediatric Hematology,The Johns Hopkins University,Disclosure Information,Cliff Takemoto MD,NONE,Objectives,Understand the physiology and regulation,of clot formation,Know what the aPTT/PT tells you,Know what the thrombophilia tests mean,How to treat a DVT(next session probably),collagen,TF,How we clot,Cut in the endothelium,Exposes platelet binding sites,Exposes tissue factor for activating coagulation,collagen,collagen,TF,TF,collagen,vWF,vWF,vWF,vWF,vWF,vWF,TF,TF,TF,TF,Platelet Activation,Platelet granule secretion,Activate fibrinogen receptor,Provides site for prothrombinase complex,Thrombin,Activation,And fibrin,deposition,RED,-platelets,GREEN,tissue factor,BLUE,-fibrin,Blood flowing this way,This is how a clot is made,Falati et al.,Nature Medicine 2002(mpeg),with permission from Nature Publishing Group,how a clot is made in vivo,Thrombin activation INITIATED by TISSUE FACTOR,(microparticles?),NEED a PLATLET SURFACE for coagulation factors,to assemble,Coagulation Cascades,reality in a test tube?,the often-asked question:“Why is coagulation so complicated?”,resolves itself into the question:“Why are there so many stages?”,R.G.Macfarlane,Nature,1964,misunderstanding breeds fear and hatred,Serine Proteases,FVIII,FV,TF,Co-Factors,FII,PC,TM,PS,FIX,FX,FVII,II,IIa,Fibrin polymers,Fibrinogen,Xa,Va,Ca,+,PL,“Prothrombinase”,IXa,VIIIa,Ca,+,PL,intrinsic,tenase,prekallikrein,HMWK XII XI,TF,VIIa,extrinsic,tenase,PT,PTT,enzyme complexes:proteasecofactor,Prothrombinase Xa Va,Intrinsic tenaseIXa VIIIa,Extrinsic tenaseVIIa TF,Also need Calcium and a phosholipid surface,Activation of thrombin:3 complexes,II,prothrombin,IIa,thrombin,Fibrin polymers,Fibrinogen,Xa,Va,Ca,+,PL,IXa,VIIIa,Ca,+,PL,Clot formation-physiology,TF,VIIa,X,initiation,propagation,A few words about contact activation,Regulate Inflammation,HK,PK,FXII deficiency,do not bleed,FXI deficiency associated,with bleeding,Cofactor,High Molecular-Weight Kininogen(HK),Protease,Prekallikrein(PK),FXII,FXI,Inibitor,C1 esterase inhibitor,C1,inh,Thrombin,IIa,procoagulant,anticoagulant,Fibrinogen,FV,FVIII,FXI,FXIII,TAFI(fibrinolysis inhibitor),Platelet Activation,Protein C/S,(bound to Thrombomodulin),intrinsic,extrinsic,Thrombin has both pro-and anti-coagulant functions,Fibrinogen Structure,Gorkun O.et al.,Blood 1997;89:4407-44.With permission from the American Society of Hematology,Activators,t-PA,u-PA,Inhibitors,PAI-1,PAI-2,a,2 antiplasmin,a,2 macroglobulin,TAFI,Plasminogen regulation,Clinical Aspects about Fibrinolysis,PAI-1-deficiency causes bleeding,-increased in DIC,inflammationprothrombotic,a,2 antiplasmindeficiency causes bleeding,Plasminogennewborns have low levels compared to adults,Tests for fibrinolytic pathway,-measure individual factors,-euglobulin clot lysis(short with increased fibrinolysis),Endogenous Anticoagulants:,Turning off the clot,Protein CVIIIa,Va(the cofactors),Protein S,AntithrombinIIa,Xa(serine proteases),TFPI VIIa/TF,II,IIa,VIIa,Xa,Va,IXa,VIIIa,Protein C,Protein S,AT III,thrombomodulin,IIa,TFPI,How to stop the clot,Protein C and Protein S,C4b binding protein,Thrombomodulin,IIa,VIIIa,Va,APC,S,S,C,cofactors,Vitamin K dependent,Protein C-serine protease,Protein S-cofactor,Activated by thrombin/TM,How the endothelium inhibits clots,Nitric,Oxide,PGI2,Inhibit platelet aggregation,thrombin,thrombomodulin,APC,antithrombin,proteoglycans,(heparan,dermatan),inactivate,FVa and FVIIIa,AT,inactivate,serine proteases,plasminogen,activators,(t-PA,u-PA),IIa,TM,TFPI,inactivate,TF/FVIIa/FX,Factor Levels and Age,Vit K,dependent,FVIII,vWF,Adapted from data from Andrew M.et al,Am J.Ped Heme onc 1990,Contact,Factors,Anticoagulant and Procoagulant Proteins are low in neonates,Anti-coagulant proteins,low,Procoagulant proteins,low,Protein C/S,Antithrombin,plasminogen,Vitamin K,dependent,factors,Normal to high:FVIII,FV,fibrinogen,Are neonates hypercoagulable?,Approach to abnormal laboratory screens,Elevated aPTT,Elevated PT,Elevated aPTT and PT,Points about,factors,Elevated aPTT,Mixing study,1:1 ratio,control+patient plasma,correction,Bleeding,FVIII,FIX,FXI,No Bleeding,Contact factors,-FXII,-PK,-HMWK,no correction,Heparin,Circulating Inhibitor,Phospholipid dependent,Lupus Anticoagulant,-DRVVT,-phospholipid neutralization,-platelet neutralization,Non-specific,Elevated aPTT and PT,Thrombin Time,Prolonged,Heparin,FDP(DIC),Fibrinogen,Low,Aquired,Liver disease,DIC,Normal,Factor Deficiencies,Common Pathway,-FV,FX,Combined Pathway,-Intrinsic/Extrinsic,-vitamin K deficiency,Fibrinogen activity,Inherited,FGN ag low/absent,-hypofibrinogenemia,-afibrinogenemia,FGN ag normal,-dysfibrinogenemia,Thrombin Time-prolonged,Reptilase Time-normal,heparin,Thrombin Time-prolonged,Reptilase Time-prolonged,Low fibrinogen,dysfibrinogenemia,Factor,Invivo T,1/2,Synthesis,Function,vitK,Fibrinogen(I)2-4 days liver -,Prothrombin(II)3 days liverSP +,V 36 hrs liver/megaCoF -,VII 3-6 hrs liverSP +,VIII 8-12 hrs liver/ECCoF -,IX 22 hrs liver SP +,X 40 hrs liverSP +,XI 80 hrs liverSP -,XII 50-70 hrs liverSP -,XIII 10 days liverTG -,VWF 12 hrs mega/EC,Characteristics of Clotting Factors,megamegakaryocyte;ECendothelial cell;SPserine protease;CoFCofactor;,TG-transglutaminase,Summary of this part,Enzyme complexes that turn on the clot and turn off the clot,(there are not that manyits not hard!),Prothrombinase,intrinsic and extrinsic tenase,Protein C/S,antithrombin,TFPI,The aPTT is not an exact simulation of clot formation in vivo,contact factors,Assembly of factors on platelet membrane,Initiation of extrinsic pathway,amplification of intrinsic,Why do you clot?(too much),Blood Flow,(Venous Stasis),Vascular Wall,(Endothelial damage),Circulating Blood Factors,(Hypercoagulability),Dr.Virchow 1866,Thrombophilia,Who to test?,What to test?,How to Treat?,Who to Test?,Does it change you managment?,Acute ManagmentNo,Future Riskmaybe,Non-catheter related VTEI think so,Catheter related VTEdebatable,Catheter related asymptomaticprobably not,Family Historyindividualize,Prior to catheter placementprobably not,menu,What is your“list”for thrombophilic work up?,TEST venous arterial,Anti-thrombin+/-,Protein C/S+/-,Activated Protein C resistance+/-,Factor V Leiden+/-,Prothrombin 20210+/-,High FVIII+/-,Antiphospholipid antibodies+,MTHFR/Homocysteine+/-+,Lp(a)+/-+,etc,What do the tests mean in Children?,(meta-analysis of 35 studies,Young et al.2008),TEST,1,st,VTE Recurrence(OR),Anti-thrombin93,Protein C82.5,Protein S63,Prothrombin 2021032,Factor V Leiden41,Lp(a)51,2 traits105,Tiered Approach to work up,First Tier Testing,Antiphospholipid Antibodies,(DRVVT,ACA,B2GPI),Antithrombin,Protein C/S,Activated Protein C Resistance(FVL),Prothrombin 20210,Homocysteine/MTHFR,Lp(a),Elevated FVIII,SecondTier Testing,Dysfibrinogenemia,FXI,FIX elevation,Fibrinolytic pathway,Find acquired risks and remove them!,CVL,malignancy,obesity,immobility,inflammation,OCPs,smoking,obstruction on vein,etc.,Laboratory Testing?,summary,Case,15 year old boy with hemoptysis for 3 weeks,Seen at Eastern Shore ER and spiral CT shows large PE,Transport Team calls youasks for management advice and recommendation for bloodwork before treatment?,Case,Antithrombin,protein C/S,APC,prothrombin 20210,Homocysteine,etcall normal.,One test you were not able to get was the antiphospholipid antibodies.He is already on heparin.When can you do the test?Does it matter?,Case 5.,DRVVT was tested on coumadin and prolonged.,The“confirm ratio”was high,suggesting,an antiphospholipid antibody,RVVT:74(27-45),1:1 mix56.2(27-45),4:1 mix65.3(27-45),aPTT30(24-34),PT10.9(10.4-12.0),RVVT:confirm 1.8(1-1.4),ratio,Antiphospholipid antibodies(APA),LA,ACA,B2GPI,Lupus Anticoagulant,prolong PTT test AND is phospholipid dependent,(mixing study with plt neutralization,DRVVT),-usually benign and transient,-can be seen in association with thrombosis,-bleeding when directed against specific factor,(FII,FV,FVIII),Anticardiolipin Antibodies,ELISA based detection,Anti-Beta2 Glycoprotein I Antibodies,ELISA based detection,Dilute Russell viper venom time,(DRVVTlike aPTT),X,Xa,Va,II,IIa,dRVVT(sec),dRVVT+PL(sec),Confirm Ratio,60 sec.,30 sec.,=,2,(1-1.4),Normal,Activate X,Sensitive to inhibition by,Antiphospholipid Ab,If the confirm ratio is high,An a phospholipid ab is present,Khamashita et al,NEJM,1995,High Intensity coumadin for Lupus Anticoagulants?,Warfarin 3,Warfarin 3,A retrospective study,Suggesting that high,Intensity warfarin should,Be used for patients with,Lupus anticoagulant,Crowther et al,NEJM,2004,High Intensity coumadin for Lupus Anticoagulants?,Prospective Trial showing,Higher incidence of recurrence,In high intensity group,Bleeding 2.2 in moderate,3.3 in high,Back to tests,Case,10 year old boy is referred to you because mother had a clot and was diagnosed with“factor 5 deficiency or something or other.”There are no records for your review.,You find out mom is heterozygous for FV Leiden.She,developed a femoral DVT1 month after delivering baby,sister.She also had recurrent miscarriages.,Case,Parents are very anxious about their children.What do you recommend?,2 years later,the boy is admitted for spinal surgery for,scoliosis.The orthopedics team wants to know about,prophylaxis.What do you recommend?,Factor V Leiden,Prevalence 5%(0-15%),Autosomal dominant,Prevents inactivation of FVa,Thrombosis risk:,FVL+/-=5X,FVL+/+=50X,FVL+/-and OCPs=30X,306,506,679,APC,Factor Va,Factor Vi,Arg 506,Arg 306,Arg 679,FVa,39 sec,30 sec,R506Q is the FV leiden mutation,What is APC resistance?,FVL:,PTT(APC),PTT,75sec,30sec,=1.3,=2.5,normal:,Back to tests,Antithrombin Deficiency,Prevalence 1/5000,Risk of thrombosis,15-20X,Acquired forms-nephrotic syndrome,liver disease,Lab-Antithrombin activity,IIa,IXa,Xa,XIa,AT III,heparin,IIi,Xi,IXi,XIi,Back to tests,Protein C and S deficiency,Protein C-1/250-500,Protein S-1/1000,Increase risk 5-10X,Acquired causes:,Both:Vit.K deficiency Protein S:estrogens,pregnancy,Homozygous protein C presents with neonatal purpura fulminans,Lab-Protein C and S activity,T,TM,C,APC,S,S,VIIIa,Va,VIIIi,Vi,C4bBP,S,Thromboembolic events with other prothrombotic risk factors,Back to tests,Factor II 20210 gene mutation,Prevalence:1-2%,Autosomal dominant,Increased mRNA processing=increased prothrombin levels,Venous thrombosis risk,2.8X,Prothrombin gene,Prothrombin RNA,Prothrombin,Prothrombin 20210 is a G to A change in the 3 untranslated portion of the gene,Prothrombin 20210 is a G to A change,in the 3 untranslated portion of the gene,Gehring et al,Nature Genetics 2001,This is a“gain of function”,Polymorphism that results in,Elevated prothrombin activity,Northern blot,Back to tests,Then you have to know about homocysteine metabolism,homocysteine,methionine,Methylation,pathway,Transulfuration,pathway,cysteine,Regeneration of folate,Pool dependent on,MTHFR,B12,folate,MS,B6,CBS,Do you want to know what MTHFR is?,Decreased MTHFR activity results in high homocysteine,MTHFR generates the folate pool required for homocysteine methylation,Mutations of MTHFR results in high homocysteine levels,What is the C677T MTHFR mutation?,C677T polymorphism in the MTFHR gene results in a thermolabile enzyme with decreased activity.,Homozygocity for C677T(TT)is prevalent(1.4%to 15%of the population),Homozygotes(TT)have high fasting homocysteine levels,Frost et al.,Nature Genetics 1995,normal,homozygote,Back to tests,Thromboembolism is a multigenic and environmental disease,Threshold,For clot,no clot,clot,Surgery,plane ride,ocps,etc.,Thromboembolism is a multigenic and environmental disease,Threshold,For clot,no clot,clot,Surgery,plane ride,ocps,etc.,FV Leiden,menu,How to treat a clot,You get call from the NICU about a 32 week premie,born with an IVC and renal vein thrombus.,What do you recommend for work up and treatment?,Treatment of DVTsWhy?,(ie.How not to clot),What are the goals of therapy?,Prevent morbidity and mortality from pulmonary emboli,Reduce morbidity from acute thrombus,Minimize postphlebitic symptoms,Prevent thromboembolic pulmonary hypertension,How to treat a clot,Anticoagulant therapyheparin,warfarin,Thrombolytic therapy,Surgical thrombectomy,Vena caval interruption,What are the goals of therapy?,InitialClot management,Candidate for thrombolysis?,yes,unfractionated heparin,CVDL consultation,Long-term anticoagulation,LMWH or coumadin,no,unfractionated heparin,or,low molecular weight heparin,thrombolysis,InitialClot management,Start Heparinization for 5 to 7 days,Standard Heparin IV:,Load 75 units/kg,1 year20 units/kg/hr,Keep APTT 60 to 85 sec,Or control ratio 1.5 to 2.5 X,LMW Heparin sq:,2 months1.0 mg/kd q12 hr,Monitor anti Xa level 4 to 6 hours after 1st or 2nd dose.,Strief et al 2003,Arch Dis Child Fetal Neonatal Ed.,Can you use LMWH in premies?,Heparin-physical characteristics,Pentasacchride ATIII binding sequence,Heparinphysical characteristicsIt binds to Antithrombin,heparin,pentasaccharide,binding,to antithrombin,Activation loop,binds to reactive,Site in serine,protease,Heparinphysical characteristics,Unfractionated heparinlonger polysaccaride chains stabilize IIa ATIII interactions and enhance IIa inactivation,Pentasacchride,Sequencebinds,ATIII,Low molecular weight heparinpreferential Xa inactivation,ATIII,IIa,Xa,ATIII,Heparinphysical characteristicsSize matters,IIa,Xa,fibrin,Oligo,mw,effect,pentasaccharide1500anti-Xa,185400anti-IIa,anti-Xa,247200anti-IIa,anti-Xa,binds fibrin,anti-HCII,ATIII,ATIII,ATIII,IIa,Outpatient Clot management,Choose between coumadin or LMW heparin for continued anticoagulation,Coumadin:,Initiation 0.2 mg/kg max 7.5 mg nomogram to adjust for 5 days,Target INR 2.0 to 3.0,INR 2.5 to 3.5 for heart valves,Keep heparin on until therapeutic(4 to 5 days),LMW Heparin:,Osteoporosis with long term use?,Target anti-Xa level 0.5 to 1.0,The Story of Warfarin,or,why did my cow die?,W,isconsin,A,lumni,R,esearch,F,oundation,Hep,A,R,I,N,Sweet grass,vanilla,The can of milk with blood that did not clot,The dead heifer and the spoiled clover hay,melilot,Vitamin K metabolism,Active Factors,Bind to Phopholipid,surface,Ca+,Vitamin K Dependent Factors,IIProtein C,VIIProtein S,IX,XGla proteins,osteocalcin,(bone),INR,Why dont you start coumadin alone?,FVII,Prot C,FII,Age and coumadin,Stief w,et al,Blood,1999,Managing coumadin in babies is a challenge,DVT treatmenthow long?,Weigh risk of recurrence vs.risk of bleeding,bleeding,clotting,2%major bleed/yr,1/5 life-threatening,anticoagulation,no anticoagulation,5-10%recurrent clot,1/20 life-threatening PE,In the end,balance a 2%bleeding risk,versus a 10%recurrent thrombotic risk,0.4%major bleed vs.0.5%major thrombus,Copyright 2004 American Society of Hematology.Copyright restrictions may apply.,Kearon,Hematology 2004;2004:439-456,Figure 2.A staged approach to selecting duration of anticoagulant therapy based on assessment of risk factors for recurrent venous thromboembolism(VTE),DVT treatme