Term
|
Definition
| can refer to decreased amount which is the typical definition or in the case of disorders of secondary hemostasis it can refer to functional deficiencies in that proteins are present in the blood, but they are not functioning correctly |
|
|
Term
| Expected results of laboratory screening tests the detect abnormalities of the proteins of secondary hemostasis |
|
Definition
| Screening tests based on length of time it takes a clot to form in plasma will be prolonged because they depend on adequate amount of clot forming proteins and functional ability of those proteins to work. These tests do not differentiate between the two (qualitative and quantitative) |
|
|
Term
| vWD Type 1 Laboratory Results |
|
Definition
| Plasma levels of VIII, vWF, and vWF: Ag are decreased or normal, bleeding time may be prolonged or normal |
|
|
Term
| vWD Type 1 Pathophysiology |
|
Definition
| Autosomal mutation which causes partial quantitative deficiency in which all multimers of vWF are present in plasma in same relative proportion as in normal plasma but they are all reduced in numbers. |
|
|
Term
| vWD Type 1 clinical symptoms |
|
Definition
| mild bleeding symptoms characterized by hemorrhage from delicate mucocutaneous tissues, bleeding into joints is NOT present |
|
|
Term
| Hemostatic proteins that are deficient in hemophilias A |
|
Definition
| Factor VIII deficiency (anti-hemophilic factor) |
|
|
Term
| Hemostatic proteins that are deficient in hemophilias B |
|
Definition
| Factor IX deficiency (Christmas factor) |
|
|
Term
| Factor VIII and IX deficiency inheritance pattern |
|
Definition
| X- linked recessive, affects sons who inherit from heterozygous carrier usually their mother |
|
|
Term
| Factor VIII and IX deficiency clinical symptoms |
|
Definition
| depending on severity can range from mild to severe bleeding problems characterized by unusual bleeding symptoms early in life (earlier depending on severity). Severe manifestations (factors < 1 units/dL) are frequent spontaneous hemarthrosis with crippling and frequent and severe spontaneous hemorrhaging. Moderate symptoms (factors = 1-5 units/dL) are bleeding at circumcision, infrequent spontaneous joint and tissue blood, excessive bleeding after surgery, trauma or minor injury. Mild symptoms (factors = 6-30 units/dL) are rare spontaneous bleeds and excessive bleeding after surgery |
|
|
Term
| Factor VIII and IX deficiency laboratory findings |
|
Definition
| mixing studies with F-VIII and F-IX return sample to 100% activity in aPTT, prolonged aPTT when low VII (>30%) and IX (>20%). Factor VIII deficiency yields prolonged aPTT and decreased factor VIII assay. Factor IX deficiency yields prolonged aPTT and decreased factor IX assay. |
|
|
Term
| vWD versus Factor VIII and IX deficiencies based on laboratory results |
|
Definition
| vWD type 1 patients will show a decreased vWF: Ag assay, while factor deficiency patients will not. The factor deficiencies are characterized by a prolonged aPTT and a decreased factor assay. |
|
|
Term
| vWD versus Factor VIII and IX deficiencies based on clinical symptoms |
|
Definition
| Factor deficiency symptoms are characterized by hemarthrosis (bleeding into the joint), vWD symptoms are usually mild, if they are present at all and it usually hemorrhage in mucosal and cutaneous tissue (not joints). |
|
|
Term
| Clinical conditions associated with acquired disorders of hemostatic proteins |
|
Definition
| DIC, Primary fibrinolysis, Liver disease, vitamin-K deficiency, and pathologic inhibitors |
|
|
Term
| Expected results in laboratory screening tests for acquired disorders of hemostatic proteins |
|
Definition
| prolonged aPTT, PT and Thrombin time (except for specific factor inhibitors) |
|
|
Term
|
Definition
| group of system secondary to a primary condition which can trigger the DIC. The most common trigger is severe infections because of the inflammatory cytokines which activate epithelial collagen to expressed tissue factor in turn activating the clotting cascade (extrinsic). |
|
|
Term
|
Definition
| the initiating event is generalized formation of thrombin and activation of coagulation. Thrombin acts on its substrates which allows for unregulated over expression of thrombin and consumption of all its substrates (fibrinogen, V, VIII, and XIII) there is a depletion of Prothrombin, activation and aggregation of platelets. Thrombin activated release of t-PA activating plasmin triggering secondary fibrinolysis, the normal inhibitory pathways which prevent system events of thrombin fail. Coagulation factors are overwhelmed and bleeding ensues. Fibrin strands in small vessels cause MAHA (schistocytes) can also obstruct blood flow and cause organ failure. |
|
|
Term
| Laboratory testing of DIC |
|
Definition
| prolonged PT, aPTT, and fibrinogen, decreased AT, plasminogen and anti-plasmin, positive for FDPs and D-Dimer, decreased platelet count and abnormal platelet function tests, schistocytes on the PBS. |
|
|
Term
| Physiologic variations in the reference ranges for hemostatic screening tests in newborns |
|
Definition
| reference ranges for coagulation factors (produced in the liver) are low because liver synthesis is not optimal at birth. Laboratory tests are prolonged which can be interpreted as normal |
|
|
Term
| Clinical consequences of abnormality in proteins of secondary hemostasis |
|
Definition
|
|
Term
| Clinical symptoms of deficiencies of fibrin forming proteins |
|
Definition
| The symptoms of both primary and secondary hemostasis disorders overlap but petechiae is unique to primary hemostasis disorders while delayed bleeding, deep muscular bleeding and spontaneous joint bleeding is characteristic of disorders of secondary hemostasis. |
|
|
Term
| Laboratory tests for disorders of primary hemostasis |
|
Definition
| can be normal (vascular disorders, except bleeding time), Platelet tests (quantitative and qualitative) are usually abnormal in platelet disorders. |
|
|
Term
| Laboratory tests for disorders of secondary hemostasis |
|
Definition
| screening tests and specific factor assays establish diagnosis, platelet studies are usually normal (except in DIC). |
|
|
Term
|
Definition
| specific molecular defects in genes and corresponding protein due to mutations during DNA replication. |
|
|
Term
| Autosomal dominant diseases |
|
Definition
|
|
Term
| X-linked recessive diseases |
|
Definition
|
|
Term
| autosomal recessive diseases |
|
Definition
| factor I, Factor II, factor V, Factor VII, Factor X, Factor XI, Factor XIII, combined (V and VIII), and vitamin-K dependent factors |
|
|
Term
| vWD subtypes inheritance pattern |
|
Definition
| Autosomal dominant inheritance, inherited |
|
|
Term
| vWD subtypes pathophysiology: Type 1 |
|
Definition
| partial quantitative deficiency in vWF in which all multimers of vWF are present but in lower concentrations than normal |
|
|
Term
| vWD subtypes pathophysiology: Type 2 |
|
Definition
| qualitative abnormality in vWF which has normal levels of vWF but the proteins are dysfunctional |
|
|
Term
| vWD subtypes pathophysiology: Type 2A |
|
Definition
| qualitative variant in which there is defective platelet-vWF interactions associated with the absence of HMW multimers in plasma, either the vWF multimers are abnormal or they are more prone to proteolysis |
|
|
Term
| vWD subtypes pathophysiology: Type 2B |
|
Definition
| - qualitative abnormality vWF in which there is an increased affinity of vWF to platelet receptor, middle and low MW multimers are present in plasma, HMW is absent in plasma. |
|
|
Term
| vWD subtypes clinical symptoms |
|
Definition
| hemorrhagic tendency, mild bleeding from delicate mucocutaneous tissues |
|
|
Term
| vWD subtypes laboratory findings: Type 1 |
|
Definition
| all tests are abnormal (bleeding time, vWF: Ag, RIPA and vWF: RCo), |
|
|
Term
| vWD subtypes laboratory findings: Type 2A |
|
Definition
| decreased platelet agglutination in response to ristocetin |
|
|
Term
| vWD subtypes laboratory findings: Type 2B |
|
Definition
| enhanced agglutination in response to reduced concentrations of ristocetin |
|
|
Term
| Deficiencies of factors of fibrin formation inheritance |
|
Definition
| deficiencies of factors VIII and IX are X-linked recessive (inherited) and deficiencies of factors II, VII, X, XI, and XIII are autosomal recessive (inherited). |
|
|
Term
| Deficiencies of factors of fibrin formation pathophysiology |
|
Definition
| deficiencies of factors VIII and IX are deficiencies of the intrinsic pathway. There is insufficient generation of thrombin by the IX/VIII complex through the intrinsic pathway, bleeding is complicated by excessive fibrinolysis because of decreased generation of thrombin and decreased inhibition of fibrinolysis by TAFI. |
|
|
Term
| Pathophysiology Factor II deficiency (Prothrombin) |
|
Definition
| is the rarest inherited bleeding disorder and is due to a qualitative defect in Prothrombin. Prothrombin is a precursor to thrombin which converts fibrinogen to fibrin. Complete lack of Prothrombin is incompatible with life |
|
|
Term
| Pathophysiology Factor VII deficiency |
|
Definition
| - the VIIa/TF complex is a key initiator of extrinsic coagulation in vivo, deficiencies can result in significant clinical manifestations |
|
|
Term
| Pathophysiology Factor X deficiency |
|
Definition
| important in the initiation of the common pathway and stabilization of the platelet plug. |
|
|
Term
| Pathophysiology Factor XI deficiency |
|
Definition
| occurs most often in Ashkenazi Jews, deficiency in the intrinsic pathway |
|
|
Term
| Pathophysiology Factor XIII deficiency |
|
Definition
| mutations which affect A or B chain of XIII, patients lack both plasma and platelet factor XIII. XIII actors after formation of fibrin, in vitro clot formation is abnormal. |
|
|
Term
| Deficiencies of factors of fibrin formation clinical symptoms |
|
Definition
| deficiencies of factors VIII and IX are indistinguishable in clinical presentation; they are readily diagnosed in patients with positive family histories. The diagnosis is based on unusual bleeding early in life, physical exam, laboratory evaluation and family history. |
|
|
Term
| Factor II (Prothrombin)clinical symptoms |
|
Definition
| severe bruising, bleeding from the nose and mouth, menorrhagia, as well as muscle bleeds, head bleeds and bleeding after trauma |
|
|
Term
| Factor VII clinical symptoms |
|
Definition
|
|
Term
| Factor X clinical symptoms |
|
Definition
| bleeding into joints, muscle bleeding, mucus membrane bleeding, nosebleeds |
|
|
Term
| Factor XI clinical symptoms |
|
Definition
| major deficiency (homozygote) presents with excessive bleeding |
|
|
Term
| Factor XIII clinical symptoms |
|
Definition
| umbilical stump bleeding in neonatal period, intracranial hemorrhage with little to no trauma, recurrent soft tissue hemorrhage, and recurrent spontaneous abortion, delayed bleeding |
|
|
Term
| Deficiencies of factors of fibrin formation laboratory findings |
|
Definition
| deficiencies of factors VIII and IX shows prolonged aPTT, mixing study will be normal |
|
|
Term
| Factor II (Prothrombin)laboratory findings |
|
Definition
| aPTT and PT are prolonged, TT and BT are normal, diagnosis by specific assay for functional Prothrombin and immunologic tests for antigen levels |
|
|
Term
| Factor VII deficiency laboratory findings |
|
Definition
| prolonged PT, normal aPTT, fibrinogen and BT, specific factor assay for VII for diagnosis, naturally low at birth |
|
|
Term
| Factor X deficiency laboratory findings |
|
Definition
| PT and aPTT screening tests are prolonged, Russell’s viper venom test (activates X) is prolonged, X assay functional and immunologic for diagnosis |
|
|
Term
| Factor XI deficiency laboratory findings |
|
Definition
| prolonged aPTT, normal PT, fibrinogen and BT |
|
|
Term
| Factor XIII deficiency laboratory findings |
|
Definition
| normal PT, aPTT, fibrinogen, BT, solubility of fibrin clots in 5 M urea or 1% monochloroacetic acid |
|
|
Term
| Laboratory tests and results for vWD subtypes |
|
Definition
| platelet count, aPTT, PT, BT, and PFA-100 (platelet aggregation studies). |
|
|
Term
| Laboratory tests and results vWD Type 1 |
|
Definition
| normal platelet count, normal or increased aPTT, normal PT, normal or increased BT, and normal aggregation with ADP, collagen, and epinephrine but decreased or absent aggregation with ristocetin. |
|
|
Term
| Laboratory tests and results vWD Type 2A |
|
Definition
| normal platelet count, increased BT |
|
|
Term
| Laboratory tests and results vWD Type 2B |
|
Definition
| decreased platelet count, increased BT |
|
|
Term
| Clinical symptoms for vWD subtypes |
|
Definition
| hemorrhagic tendency depends on type; both types are characterized by hemorrhage from delicate mucocutaneous tissues |
|
|
Term
| Laboratory tests and results for deficiencies of factors VII and IX |
|
Definition
| platelet count, PFA-100, PT, aPTT, BT and factor specific assays. All normal laboratory results except for prolonged aPTT, factor VIII deficiency a decreased factor VIII assay, and in factor IX deficiency a decreased factor IX assay. |
|
|
Term
| Clinical symptoms for deficiencies of factors VII and IX |
|
Definition
| unusual bleeding symptoms early in life, family history, physical exam and laboratory evaluation, bleeding into joints |
|
|
Term
| Laboratory tests and results for Bernard-Soulier disease |
|
Definition
| platelet count is normal or decreased, increased BT, abnormal platelet aggregation with ristocetin, giant platelets seen in PBS |
|
|
Term
| Clinical symptoms for Bernard-Soulier disease |
|
Definition
| bleeding symptoms similar to thrombocytopenia (excess, abnormal bleeding), giant platelets |
|
|
Term
| Laboratory tests and results for Glanzmann’s Thrombasthenia |
|
Definition
| normal platelet count, increased BT, and abnormal platelet aggregation studies with ADP, collagen and epinephrine |
|
|
Term
| Clinical symptoms for Glanzmann’s Thrombasthenia |
|
Definition
| bleeding symptoms in infancy and involved superficial areas of the body characteristic of platelet abnormalities, can cause death |
|
|
Term
| Conditions that result in acquired abnormalities of the hemostatic system |
|
Definition
| DIC, Liver disease, Vitamin K deficiency, acquired pathological inhibitors |
|
|
Term
|
Definition
| secondary to a condition that serves as a trigger, the initiating even is a generalized or systemic formation of thrombin and activation of coagulation, thrombin circulates and acts on its substrates causing a consumption of coagulation factors, the problem is that there is a failure in the mechanisms that limit blood clotting and thrombin generation and bleeding ensues. Fibrin strands within vessels damage the RBCs as they flow through causing MAHA (schistocytes). Fibrin also obstructs the vasculature and can result in hypoxia and organ failure. |
|
|
Term
| Confirmatory laboratory procedures for DIC |
|
Definition
| PT, aPTT, and fibrinogen are prolonged, decreased AT, plasminogen and anti-plasmin levels, positive for FDP and D-Dimer, decreased platelet count and platelet function tests are abnormal, schistocytes and thrombocytopenia on the PBS |
|
|
Term
| Liver Disease pathophysiology |
|
Definition
| disease and inhibition of liver activity inhibits all hemostatic functions because the liver synthesizes most procoagulant factors, fibrinolytic proteins and naturally occurring hemostatic inhibitors. |
|
|
Term
| Confirmatory laboratory procedures for Liver Disease |
|
Definition
| all screening coagulation tests are prolonged, platelet count can be decreased, positive for hyper-splenism and decreased TPO, increased FDPs and a lack of hepatic clearance of FDPs and plasminogen activators |
|
|
Term
| Vitamin K deficiency pathophysiology |
|
Definition
| malabsorptive syndromes, biliary tract obstruction, and prolonged antibodies can cause the precursor proteins to vitamin K to lack the calcium binding sites (nonfunctional) which induces functional deficiencies in all of the vitamin K dependent proteins. |
|
|
Term
| Confirmatory laboratory procedures for Vitamin-K deficiency |
|
Definition
| PT and/or aPTT prolonged for newborns |
|
|
Term
| Acquired pathological inhibitors pathophysiology |
|
Definition
| usually associated with diseases and drugs, inhibitor deficiencies can interfere with or neutralize clotting factor activity |
|
|
Term
| Confirmatory laboratory procedures for acquired pathological inhibitors |
|
Definition
| prolonged screening test is not corrected with 1:1 mixture with normal plasma (mixing study) |
|
|
Term
| Laboratory screening methods for deficiencies |
|
Definition
| mixing studies correct abnormal coagulation tests |
|
|
Term
| Laboratory screening methods for inhibitors |
|
Definition
| mixing studies do not correct abnormal coagulation tests |
|
|
Term
| A patient who has a deficiency of a clotting factor could have |
|
Definition
| inherited an abnormal gene from a parent, aquired the deficiency because of another disease present, or decreased amount of the particular factor in the blood |
|
|
Term
| Why do patients who have deficiencies of clottin factors usually have abnormal bleeding? |
|
Definition
| Fibrin formation is slower and less effective |
|
|
Term
| What clotting factor is deficient in a patient with hemophilia? |
|
Definition
|
|
Term
| The most probable cause of bleeding when platelet aggregation with risotcetin is abnormal, aPTT is prolonged and F-VIII assay is abnormal |
|
Definition
|
|
Term
| what laboratory test that is abnormal in vWD is different from that of a patient with hemophilia A |
|
Definition
| platelet aggregation studies |
|
|
Term
| What result of a platelet count would you expect in a patient with hemophilia A? |
|
Definition
|
|
Term
| Which are characteristics of a patient with DIC? |
|
Definition
| prolonged PT, aPTT, and decreased platelet count |
|
|
Term
| What result would be expected in a newborn infant? |
|
Definition
| longer aPTT test than in an adult |
|
|
Term
| The results indicating abnormal aggregation with ristocetin indicate that the patient has a defect in what |
|
Definition
|
|
Term
| WHat is the usual inhereitence pattern of vWD |
|
Definition
|
|
Term
| What is characteristic of Type 1 vWD? |
|
Definition
| decreased amounts of all VWF multimers |
|
|
Term
| what laboratory procedure analyzes vWF qualitatively for abnormalities of the molecular structure? |
|
Definition
| SDS-page gel electrophoresis |
|
|
Term
| What is the cause of von Willebrand disease? |
|
Definition
| genetic mutations in the vWF gene |
|
|
Term
| What would the presence of delayed bleeding and deep muscular hematomas be most likely in? |
|
Definition
| a patient with F-VIII deficiency |
|
|
Term
| What disease would most likley find an abnormal PT? |
|
Definition
|
|
Term
| What is true concerning aquired circulating pathologic to single coagulation factors? |
|
Definition
| They cause the same symptoms in the patient as an inhereited deficency of the same factor |
|
|
Term
| What is true in the condition known as DIC? |
|
Definition
| Fibrinogen and platelets becomes depleated |
|
|
Term
| What laboratory test is helpful in differentiating primary and secondary fibrin(ogeno)lysis? |
|
Definition
|
|
Term
| Why do patients with type 1 VWD have 25-50% of VWF in their plasma? |
|
Definition
| autosomal dominant, abnormalities in one gene, other gene is functional |
|
|
Term
| Why do type 1 VWD patients have corresponding decrease in F-VIII in their plasma? |
|
Definition
|
|
Term
| What causes a true quantitative decrease in F-VIII |
|
Definition
| tests for function and immunologic activity are both decreased |
|
|
Term
| Equal decrease in F-VIII assay, VWF:RCo and VWF: Ag assay |
|
Definition
|
|
Term
| Antigenic properties of VWF |
|
Definition
|
|
Term
| functional activity of F-VIII |
|
Definition
|
|
Term
| complex of F-VIII and VWF? |
|
Definition
|
|
Term
| Why are platelet functions abnormal in VWD? |
|
Definition
| VWF is necessary for platelets to adhere to collagen, ristocetin replaces collagen in the test. Without VWF platelets do not adhere and do not aggregate |
|
|
Term
| Why is TT abnormal in afibrinogemia |
|
Definition
| no fibrinogen to convert to fibrin, TT depends on the adequte conversion of soluble fibrinogen to fibrin |
|
|
Term
| Why is TT abnormal in dysfibrinogenemia |
|
Definition
| fibrinogen with abnormal ability to conver to fibrin |
|
|
Term
| Why is PT but not aPTT prolonged in F-VII deficiency |
|
Definition
| Reagent in PT is tissue thromboplastin which is activated by F-VII, fibrin formation is delayed because deficient F-VII. No thromboplastin in the aPTT, fibrin is formed by activating contact factor system and F-VII is bypassed |
|
|
Term
| Why are tests normal in patients with F-XIII deficiency? |
|
Definition
| all tests depend on fibrin formation regardless of cross-linking. F-XIII functions after fibrin is formed |
|
|
Term
| Why is thrombocytopenia present with DIC? |
|
Definition
| platelets are consumed, activated by thrombin and incorporated into the fibrin clots within circulation |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| neither PT or aPTT prolonged |
|
|
Term
| Which lab test distinguishs DIC from Hemophilia A? |
|
Definition
| aPTT is prolonged and F-VIII assay is decreased in hemophilia A, everything else is normal. All factor assays are abnormal, platelet count is abnormal in DIC |
|
|
Term
| The traumatic injury to the head and the wound infection are common causes of |
|
Definition
|
|
Term
| The reason for the abnormal prothrombin time and APTT in DIC is |
|
Definition
| acquired deficiency of several clotting factors because the patient has abnormal clotting within the blood vessels |
|
|
Term
| Platelet adhesion to collagen requires the presence of adequate functional: |
|
Definition
| von Willebrand factor and glycoprotein Ib |
|
|
Term
| Patients with blood group O have: |
|
Definition
| lower levels of von Willebrand factor than patients with other blood groups |
|
|
Term
| Which of the following laboratory results is typical of a patient with a disorder of one of the clotting proteins? |
|
Definition
| prolonged prothrombin time and/or APTT |
|
|
Term
| A clotting factor deficiency that is inherited in an X-linked manner is: |
|
Definition
|
|
Term
| Patients with clotting factor deficiencies may have abnormal bleeding because: |
|
Definition
| Fibrin is formed more slowly and is inadequate to stop bleeding. |
|
|
Term
| The laboratory test that is necessary to differentiate a factor VIII deficiency from a factor IX deficiency is: |
|
Definition
|
|
Term
| Which hemostasis screening test(s) will be abnormal in patients with hemophilia A or B? |
|
Definition
|
|
Term
| What should you do next is there is a prolonged aPTT? |
|
Definition
| Mix patient's plasma with normal plasma and repeat the APTT. |
|
|
Term
| If the repeated APTT result was 120.3 sec. the results of the repeated APTT indicate: |
|
Definition
| The original APTT test was not corrected. |
|
|
Term
| What is the most likely interpretation of the uncorrected aPTT? |
|
Definition
|
|
Term
| Which of the following procedures should be performed next to diagnose Lupus anticoagulant? |
|
Definition
| a dilute Russell's viper venom test or a kaolin clotting time test |
|
|
Term
| The lupus anticoagulant is: |
|
Definition
| an antibody that reacts with phospholipids in the reagents for hemostasis tests, causing prolongation of the tests |
|
|
Term
| The structure of the von Willebrand factor molecule is: |
|
Definition
| a large multimer composed of several identical dimeric subunits oriented by their N terminal ends |
|
|
Term
| The subtype of von Willebrand disease in which patients would have abnormal functional tests but normal immunologic tests for von Willebrand factor is: |
|
Definition
|
|
Term
| Which of the following is a functional test for von Willebrand factor? |
|
Definition
| ristocetin cofactor assay |
|
|
Term
| Vitamin K deficiency will cause: |
|
Definition
| deficiencies of functional forms of coagulation factors II, VII, IX, and X |
|
|
Term
| Patients with dysfibrinogenemia will usually demonstrate: |
|
Definition
| abnormal thrombin time as the only abnormal test for hemostasis |
|
|
