Hemostasis and Coagulation Disorders Quiz
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Questions and Answers

What is the most common type of bleeding symptom associated with von Willebrand's Disease (vWD)?

  • Deep tissue bleeding
  • Mucosal bleeding (correct)
  • Internal organ bleeding
  • Musculoskeletal bleeding

    • Which of the following statements is TRUE regarding Hemophilia A (HA) versus vWD?

  • HA is more common in females, while vWD is more common in males.
  • HA primarily affects males, while vWD can affect both genders equally. (correct)
  • HA is more common than vWD.
  • vWD is more common than HA.

    • Which of the following is NOT a treatment option for Hemophilia A?

  • Antifibrinolytic agent
  • Desmopressin (correct)
  • FVIII and vWF infusion
  • None of the above

    • What is the primary cause of Vitamin K deficiency in newborns?

    <p>Immature liver cells and low quantities in breast milk (C)</p> Signup and view all the answers

    Which of the following coagulation factors are affected by Vitamin K deficiency?

    <p>Factor II, VII, IX, X (B)</p> Signup and view all the answers

    Which of the following is NOT a common cause of Vitamin K deficiency in children and adults?

    <p>Excessive intake of Vitamin K-rich foods (A)</p> Signup and view all the answers

    Which of the following laboratory findings is NOT typically associated with Vitamin K deficiency?

    <p>Elevated INR (C)</p> Signup and view all the answers

    Which of the following is a treatment option specifically for Type 2B von Willebrand Disease?

    <p>Antifibrinolytic agent (B)</p> Signup and view all the answers

    Which of the following is NOT a direct consequence of impaired vitamin K absorption due to biliary obstruction?

    <p>Thrombocytopenia because of impaired thrombopoietin production (C)</p> Signup and view all the answers

    How does disseminated intravascular coagulation (DIC) contribute to hemolytic anemia?

    <p>DIC leads to widespread fibrin deposition in small vessels, causing mechanical damage to red blood cells. (B)</p> Signup and view all the answers

    Which of the following conditions is NOT a known trigger for disseminated intravascular coagulation (DIC)?

    <p>Severe anemia (C)</p> Signup and view all the answers

    What is the underlying mechanism by which liver disease can lead to disseminated intravascular coagulation (DIC)?

    <p>Liver disease impairs the synthesis of antithrombin, protein C, and 2-macroglobulin, leading to a hypercoagulable state. (C)</p> Signup and view all the answers

    What is the primary reason for administering fresh frozen plasma or plasma concentrate in the treatment of disseminated intravascular coagulation (DIC)?

    <p>To replace deficient clotting factors that are depleted during widespread intravascular coagulation. (B)</p> Signup and view all the answers

    Which laboratory test is most specific for the diagnosis of disseminated intravascular coagulation (DIC)?

    <p>Elevated D-dimer levels (D)</p> Signup and view all the answers

    Which of the following is a common clinical manifestation of disseminated intravascular coagulation (DIC)?

    <p>Massive bleeding due to consumption of platelets and clotting factors. (B)</p> Signup and view all the answers

    What is the primary rationale for recommending oral vitamin K as a prophylactic measure for patients with liver disease?

    <p>To correct deficiencies in coagulation factors II, VII, IX, and X, which are dependent on vitamin K for their synthesis. (A)</p> Signup and view all the answers

    In a mixing study, what is the expected outcome if factor deficiency is suspected?

    <p>The PTT will normalize. (A)</p> Signup and view all the answers

    What is the primary treatment for both hemophilia A and B?

    <p>Factor VIII replacement therapy. (B)</p> Signup and view all the answers

    Which of the following statements accurately describes desmopressin therapy?

    <p>Desmopressin is a synthetic vasopressin analogue that primarily targets factor VIII. (B)</p> Signup and view all the answers

    What is the distinguishing feature of acquired hemophilia A?

    <p>It is caused by autoantibodies against factor VIII. (B)</p> Signup and view all the answers

    Why is it important to note that factor IX levels can be low at birth?

    <p>Low factor IX levels at birth are not necessarily indicative of hemophilia B. (B)</p> Signup and view all the answers

    Why are umbilical cord blood samples more accurate for detecting low factor VIII levels compared to factor IX levels?

    <p>Factor VIII levels are not affected by the age of the infant, while factor IX levels are. (C)</p> Signup and view all the answers

    What is the primary benefit of prophylactic treatment for hemophilia?

    <p>Reduction in bleeding episodes and hospitalizations. (C)</p> Signup and view all the answers

    Which of the following statements accurately describes the inheritance pattern of both hemophilia A and B?

    <p>Both are inherited as X-linked recessive disorders. (C)</p> Signup and view all the answers

    Which of the following is NOT a characteristic of Hemophilia B?

    <p>Prolonged bleeding time (D)</p> Signup and view all the answers

    Which of the following statements about Hemophilia is FALSE?

    <p>Hemophilia is always associated with family history. (C)</p> Signup and view all the answers

    Which type of Von Willebrand disease (VWD) is characterized by a total lack of vWF?

    <p>Type 3 (A)</p> Signup and view all the answers

    In Von Willebrand disease, which of the following laboratory findings is typically NOT observed?

    <p>Normal platelet count (A)</p> Signup and view all the answers

    What is the function of vWF?

    <p>Both A and C (D)</p> Signup and view all the answers

    Which of the following is a subtype of Type 2 VWD?

    <p>Type 2B (C)</p> Signup and view all the answers

    In which type of VWD is the vWF unable to interact with platelets properly?

    <p>Type 2 (B)</p> Signup and view all the answers

    Which of the following is measured by the VWF:Ag specialized lab investigation?

    <p>Concentration of vWF protein in plasma (A)</p> Signup and view all the answers

    What is the primary distinguishing feature between Hemophilia A and Hemophilia B?

    <p>The specific clotting factor deficiency. (D)</p> Signup and view all the answers

    Which of the following is NOT a common clinical feature of Hemophilia A?

    <p>Increased risk of thrombosis. (C)</p> Signup and view all the answers

    What is the most likely explanation for the development of a "Hemophilic pseudo tumor"?

    <p>Repeated bleeding into a muscle or bone, forming a cystic swelling. (B)</p> Signup and view all the answers

    Which of the following laboratory tests would be most useful in differentiating Hemophilia A from a normal patient?

    <p>Partial Thromboplastin Time (PTT) (B)</p> Signup and view all the answers

    Why are males more commonly affected by Hemophilia A than females?

    <p>Males inherit only one X chromosome, making them more susceptible to recessive X-linked disorders. (B)</p> Signup and view all the answers

    Which of the following is a true statement about the inheritance pattern of Hemophilia A?

    <p>It is an X-linked recessive disorder, meaning that a male will inherit it from his mother and a female will be a carrier if she inherits it from her mother. (B)</p> Signup and view all the answers

    What is the correlation between the severity of Hemophilia A and the level of Factor VIII in the blood?

    <p>Patients with lower Factor VIII levels tend to experience more severe bleeding episodes. (C)</p> Signup and view all the answers

    A patient presents with recurrent, painful joint bleeds and a history of prolonged bleeding after dental procedures. Which of the following tests is most likely to be used to confirm the diagnosis of Hemophilia A?

    <p>Partial Thromboplastin Time (PTT) (B)</p> Signup and view all the answers

    Flashcards

    Hemophilia A

    A genetic disorder due to deficiency of factor VIII (FVIII).

    Hemophilia B

    A genetic disorder caused by deficiency of factor IX (FIX).

    Von Willebrand's Disease

    A bleeding disorder caused by lack of von Willebrand factor (vWf).

    Inheritance pattern of Hemophilia A

    Hemophilia A is transmitted as X-linked recessive inheritance.

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    Bleeding manifestations

    Symptoms include bruising, spontaneous bleeding, and hemarthrosis (joint bleeding).

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    Severity of Hemophilia A

    Severity depends on the level of FVIII in the blood; lower levels mean more severe bleeding.

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    Clinical feature: Hemarthrosis

    Recurrent painful bleeding into the joints.

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    Laboratory tests for Hemophilia A

    Initial tests include CBC, PT, PTT, and BT to assess bleeding capabilities.

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    Prolonged PTT in Hemophilia

    In hemophilia A and B, PTT is prolonged due to intrinsic pathway disruption.

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    Mixing Study Purpose

    A mixing study helps determine if prolonged PTT is due to factor deficiency.

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    Factor VIII Activity

    Hemophilia is diagnosed if factor VIII activity is less than 40% of normal.

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    Molecular Genotyping

    Used to confirm hemophilia diagnosis and predict disease severity.

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    Desmopressin Function

    Desmopressin boosts plasma levels of FVIII and vWF from endothelial cells.

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    Acquired Hemophilia A

    Non-genetic hemophilia A caused by autoantibodies against factor VIII.

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    Hemophilia B Inheritance

    Identical to hemophilia A with Factor IX deficiency; lower incidence.

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    Diagnostic Testing for Newborns

    Umbilical cord blood samples accurately indicate factor levels at birth.

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    Ristocetin

    An antibiotic that causes VWF to bind to platelets and produce platelet clumps.

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    Von Willebrand's Disease (VWD)

    A bleeding disorder caused by deficiency or dysfunction of von Willebrand factor, affecting platelets.

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    Hemophilia A (HA)

    A genetic bleeding disorder mainly affecting males, characterized by deep tissue bleeding.

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    Mucosal Bleeding

    Bleeding that often occurs in VWD, affected skin and mucous membranes.

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    Vitamin K Deficiency

    A condition caused by inadequate diet, malabsorption, or drugs like warfarin, leading to bleeding issues.

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    Acquired Coagulation Disorders

    More common than inherited disorders, involving multiple clotting factor deficiencies.

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    Hemorrhagic Disease of the Newborn

    Caused by Vitamin K deficiency in newborns, leading to bleeding due to immature liver.

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    Laboratory Findings

    Prolonged PT and aPTT indicate vitamin K deficiency, with normal platelet counts.

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    Laboratory findings in Hemophilia B

    Prolonged APTT and reduced FIX Clotting assay, with normal bleeding time and PT.

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    Types of Von Willebrand's Disease

    Three types: Type 1 (reduced vWF), Type 2 (abnormal vWF), Type 3 (little or no vWF).

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    Type 2 subtypes of vWD

    Type 2 is divided into 4 subtypes based on vWF functionality: 2A (loss of high multimers), 2B (high platelet affinity).

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    Functions of von Willebrand factor

    Promotes platelet adhesion to damaged endothelium and carries FVIII to protect it from destruction.

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    Laboratory findings in vWD

    Prolonged bleeding time, low FVIII, prolonged aPTT, low vWF, normal platelet count (except type 2B).

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    Specialized lab investigation for vWD

    Includes VWF:Ag immunoassay and VWF:RCo functional assay to measure vWF levels and function.

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    Oral Vitamin K Prophylaxis

    Preventive treatment using vitamin K to support clotting.

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    Thrombocytopenia

    A decrease in platelet count, commonly due to liver disease.

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    Dysfibrinogenaemia

    Functional abnormality of fibrinogen affecting clot formation.

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    Disseminated Intravascular Coagulation (DIC)

    A serious condition causing excessive clotting and bleeding from clotting factor consumption.

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    Causes of DIC

    Conditions like liver disease, infections, or vascular damage triggering DIC.

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    Laboratory Findings in DIC

    Indicators include low platelets, prolonged coagulation times, and high D-dimer levels.

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    Treatments for DIC

    Includes fresh frozen plasma and RBC transfusion to manage bleeding.

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    Fibrin Degradation Products (FDP)

    Substances formed from the breakdown of fibrin during clot resolution.

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    Study Notes

    Coagulation Disorders

    • Coagulation disorders are conditions affecting blood clotting.

    Inherited Coagulation Disorders: Overview

    • Hemophilia:
      • Hemophilia A – Factor VIII deficiency
      • Hemophilia B – Factor IX deficiency
    • von Willebrand's Disease (vWD):
      • Types 1-3
      • Characterized by lack or insufficient production of von Willebrand factor (vWF)

    Hemophilia

    • Also known as "love of bleeding"
    • Bleeding manifestations of both Hemophilia A & B are identical
    • Some infants are asymptomatic until experiencing minor trauma, resulting in bruising and spontaneous bleeding, particularly into deep tissues (joints, muscles, soft tissues).
    • Bleeding after trauma or surgery can be life-threatening.
    • Causes lifelong bleeding problems.

    Hemophilia A

    • Bleeding due to deficiency of Factor VIII coagulant activity.
    • Severity related to Factor VIII level in the blood.
    • Low levels (<1 iu/dL) result in frequent spontaneous bleeding into joints or muscles.
    • Inherited as recessive X-linked.
    • Males are affected, females are carriers.
    • Defect is an absence/low level of plasma Factor VIII.

    X-linked recessive inheritance

    • Diagram showing inheritance pattern of X-linked recessive disorders (Males affected, females carriers).

    Clinical Features of Hemophilia A

    • Infants may experience joint and soft tissue bleeds and excessive bruising when becoming active.
    • Dental extraction can lead to prolonged bleeding.
    • Hemarthrosis (recurrent joint bleeding) leads to joint deformity and disability (if poorly treated).
    • Hemophilic pseudotumor is a rare complication of hemophilia involving progressive cystic swelling in muscles/bones caused by repeated bleeding.
    • Hematuria (blood in urine) is possible.
    • Gastrointestinal bleeding is a possible symptom.

    Severity of Hemophilia A

    • Severity related to Factor VIII level (iu/dL)
      • Severe: Factor level 0-1
      • Moderate: Factor level 2-5
      • Mild: Factor level 5-30

    Coagulation Pathway

    • Diagram illustrating intrinsic and extrinsic pathways.
    • Key factors: Factor XII, XI, IX, VIII, X, VII, V, prothrombin, thrombin, fibrinogen, fibrin.
    • Key times: aPTT, PT, TT.

    Laboratory Investigations (Hemostasis Tests) for HA

    • Initial work includes complete blood count (CBC), prothrombin time (PT), partial thromboplastin time (PTT), and bleeding time (BT).
    • In HA & HB, PTT prolonged, whilst PT & BT are normal.
    • Mixing study is followed after prolonged PTT is detected.
    • If factor deficiency suspected, PTT should normalize in mixing study.
    • Hemophilia is usually diagnosed if factor activity is less than 40% of normal factor activity.
    • Molecular genotyping confirms diagnosis and predicts severity.

    Other Laboratory Investigation for Carrier Detection and Antenatal Diagnosis

    • Measure plasma levels of Factor VIII.
    • DNA probes detect mutations in carriers.
    • Fetal DNA analysis through 8-10 weeks gestation biopsies.
    • Antenatal diagnosis via UV- ultrasound guided needle aspiration in 16-20 weeks gestation.

    Treatments

    • Factor VIII replacement therapy (recombinant factor or frozen plasma concentrate).
    • Desmopressin (synthetic vasopressin analog): stimulates release of FVIII and vWF from endothelial cells, boosting plasma levels.
    • Prophylactic treatments: stored FVIII at home to reduce cerebral and muscle bleeds, reducing hospitalizations, and improving quality of life.

    Non-Genetic Form of Hemophilia A

    • Caused by autoantibodies against Factor VIII (acquired hemophilia A).
    • Associated with certain cancers, autoimmune diseases/response to treatment, or occurring after childbirth.

    Hemophilia B

    • Also known as Christmas disease; Factor IX deficiency.
    • Similar inheritance and clinical features to Hemophilia A.
    • Distinguished from Hemophilia A by specific coagulation assays.
    • Incidence approximately 1/5 that of Hemophilia A.
    • Factor IX levels are initially low at birth, but reach normal levels around six months.
    • Umbilical cord blood samples are more accurate for finding Factor VIII deficiencies (lower than Factor IX at birth).

    Hemophilia B: Treatments and Findings

    • Treatment: FIX infusions (longer half-life than FVIII).
    • Abnormal Findings:
      • Prolonged aPTT
      • Reduced FIX clotting assay
      • Normal bleeding time
      • Normal PT

    Additional Info: Hemophilia

    • Hemophilia can occur even without a family history; it can arise due to spontaneous mutations affecting the F8 or F9 gene (affecting clotting factors).
    • The vast majority of Hemophilia cases are due to gene defects.
    • Over 1000 mutations in factor VIII and IX genes identified, approximately 30% resulting from spontaneous mutations.

    von Willebrand's Disease (vWD)

    • Abnormalities in vWF levels (reduced levels or abnormal function) result from point mutations / major deletions.
    • vWF is a large protein (300 kDa) forming multimers.
    • Inherited as autosomal dominant.
    • Characterized by mucosal bleeding (nosebleeds, gum bleeding).
    • Bleeding can occur after dental extraction and following trauma.

    vWF – Multi-functional Proteins

    • vWF promotes platelet adhesion & aggregation to damaged endothelium.
    • vWF acts as a carrier molecule for FVIII, protecting it from premature destruction.

    vWD - 3 Types

    • Type 1: Reduced vWF (mild).
    • Type 2: Abnormal vWF.
      • 2A: Loss of high molecular weight multimers (HMWM).
      • 2B: Increased affinity of vWF for platelets (abnormal vWF attachment when no injury to platelets, causing thrombocytopenia and reduced vWF production when clotting is required)
      • 2M: Defective binding site on GPIb preventing vWF from attaching to platelets and causing poor platelet aggregation.
      • 2N: Reduced affinity for FVIII.
    • Type 3: Very low or lacking vWF (severe).

    vWD – Lab Findings

    • Prolonged bleeding time
    • Low FVIII
    • Prolonged aPTT
    • Low vWF
    • Defective platelet aggregation
    • Normal platelet count (except low in type 2B)

    Specialized Lab Investigations for vWD

    • VWF:Ag (immunoassay): measures vWF protein concentration in plasma.
    • vWF:RCo (functional assay): measures ability of vWF to interact with normal platelets (ristocetin-induced platelet agglutination).

    vWD Treatments

    • Antifibrinolytic agents (type 2B)
    • Desmopressin (type 1 vWD)
    • FVIII and vWF infusions for patients with very low vWF levels.

    Hemophilia A vs. vWD: Differences

    • Gender: Hemophilia A mainly affects males, whereas vWD affects both genders equally.
    • Bleeding symptoms: Hemophilia A typically involves deep tissue bleeding (joints, internal organs), while vWD often presents with mucosal bleeding (in tissues and cavities exposed to the environment).

    Acquired Coagulation

    • More common than inherited disorders.
    • Involves deficiencies in multiple clotting factors.

    Vitamin K Deficiency

    • Causes:
      • Inadequate diet
      • Malabsorption
      • Inhibition by drugs (e.g., warfarin).
    • Results in deficiencies of factors II, VII, IX, X, protein C, and protein S.
    • Hemorrhagic disease of the newborn may be a consequence.
    • Associated with obstructive jaundice, or pancreatic problems.

    Hemorrhagic Disease of the Newborn

    • Vitamin K deficiency due to immature liver cells, lack of gut bacteria, low vitamin K levels in breast milk.

    Liver Disease and Hemostasis

    • Liver disease can affect hemostasis in several ways, including:
    • Impaired vitamin K absorption.
    • Reduced synthesis of coagulation factors (II, VII, IX, X).
    • Synthesis of coagulation inhibitors and promoting DIC(disseminated intravascular coagulation).
    • Thrombocytopenia
    • Dysfibrinogenaemia.

    Disseminated Intravascular Coagulation (DIC)

    • Widespread fibrin deposition and consumption of coagulation factors & platelets.
    • Triggered by many factors releasing procoagulants and causing endothelial damage/activation of haemostasis.
    • Pathogenesis: entry of procoagulants into circulation (amniotic fluid embolism, liver disease, placental separation, cancer, snake venom, endothelial damage, infections/immune response/vasculitis; severe burns).
    • Lab findings: low platelet counts, prolonged PT, PTT, increased D-dimers, and fibrin degradation products.

    DIC Treatments

    • Fresh frozen plasma or plasma concentrate
    • RBC transfusion
    • Antithrombin and protein C to inhibit further DIC.

    Coagulation Deficiency Caused by Antibodies

    • Alloantibodies to Factor VIII in some hemophilia cases cause bleeding.
    • SLE ( Systemic Lupus Erythematosus) and other autoimmune disorders can cause lupus anticoagulant which interferes with coagulation.
    • Treatment: immunosuppression or factor replacement.

    Massive Transfusion Syndrome

    • Characterized by dilution effects on platelets, coagulation factors, and inhibitors.
    • Platelet counts and coagulation function are often reduced after prolonged 24hr blood storage at 4°C.
    • Preexisting bleeding disorders can increase these problems.

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    Test your knowledge on hemostasis and coagulation disorders, focusing on von Willebrand's Disease, Hemophilia A, and Vitamin K deficiencies. This quiz also covers the implications of disseminated intravascular coagulation and its effects. Dive into the complexities of bleeding disorders and their treatments.

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