Chronic ITP and Hereditary Hemorrhagic Telangiectasia
47 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is NOT a characteristic of Chronic ITP?

  • Increased or normal numbers of megakaryocytes in the bone marrow
  • Bleeding symptoms such as petechiae, hemorrhage, bruising, menorrhagia, and mucosal bleeding
  • Sudden onset and short-term manifestation (less than 6 months) (correct)
  • Platelet count of 10-50 x 10^9/l

Which of the following is a key characteristic differentiating Chronic ITP from Acute ITP?

  • The occurrence of bleeding symptoms
  • The involvement of megakaryocytes
  • The duration of the condition (correct)
  • The presence of auto-antibodies against platelets

In Post-transfusion Purpura, the formation of antibodies against which platelet antigen leads to thrombocytopenia?

  • HPA-1b
  • HPA-2b
  • HPA-1a (correct)
  • HPA-2a

Which of the following is NOT a common treatment approach for Chronic ITP?

<p>Platelet transfusion (D)</p> Signup and view all the answers

What is the underlying mechanism by which drug-induced immune thrombocytopenia occurs?

<p>Drug-dependent antibodies in the patient's serum target platelet proteins. (D)</p> Signup and view all the answers

Which of the following statements accurately describes the hereditary nature of vascular bleeding disorders?

<p>Vascular bleeding disorders can be either inherited or acquired, depending on the underlying cause. (C)</p> Signup and view all the answers

What is the primary characteristic of Hereditary Hemorrhagic Telangiectasia (HHT)?

<p>Dilated microvascular swellings and arteriovenous malformations. (C)</p> Signup and view all the answers

What does the term 'telangiectasia' refer to in the context of HHT?

<p>Dilated microvascular swellings. (A)</p> Signup and view all the answers

What is a potential complication associated with Arteriovenous Malformations (AVMs) in HHT patients?

<p>All of the above. (D)</p> Signup and view all the answers

Which of the following organs can be affected by HHT?

<p>Skin, mucous membranes, and internal organs such as the lungs and brain. (C)</p> Signup and view all the answers

Why might HHT patients experience iron deficiency (IDA)?

<p>Due to recurrent bleeding, leading to iron loss. (D)</p> Signup and view all the answers

What is a common treatment approach for HHT?

<p>Laser therapy to treat telangiectasia. (A)</p> Signup and view all the answers

What is the main reason why people with HHT can only manage the disease and not fully treat it?

<p>The genetic component of HHT makes a full cure impossible. (B)</p> Signup and view all the answers

Which of the following is NOT a factor contributing to hemostasis?

<p>Increased blood pressure (D)</p> Signup and view all the answers

Which of the following is NOT an example of an acquired vascular bleeding disorder?

<p>Simple bruising (D)</p> Signup and view all the answers

Which of the following is a factor in the extrinsic pathway of coagulation?

<p>Factor VII (C)</p> Signup and view all the answers

Which of the following is a characteristic feature of defective platelet function?

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

Which of the following is an inherited disorder of platelet function?

<p>Bernard-Soulier syndrome (C)</p> Signup and view all the answers

Which of the following contributes to platelet aggregation?

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

Which of the following is a characteristic feature of vascular bleeding disorders?

<p>Petechiae and purpura (C)</p> Signup and view all the answers

Which of the following factors is NOT involved in the clotting cascade?

<p>Factor XII (A)</p> Signup and view all the answers

Which of the following is a key step in the fibrinolytic pathway?

<p>Activation of plasminogen to plasmin (D)</p> Signup and view all the answers

Which of the following is NOT a potential cause of thrombocytopenia?

<p>Elevated red blood cell count (A)</p> Signup and view all the answers

In thrombotic thrombocytopenic purpura (TTP), what is the underlying mechanism that leads to the formation of microthrombi?

<p>Deficiency of ADAMTS-13 results in insufficient vWF breakdown, leading to platelet aggregation. (C)</p> Signup and view all the answers

What is the characteristic finding on a blood smear in a patient with TTP?

<p>Schistocytes (D)</p> Signup and view all the answers

In disseminated intravascular coagulation (DIC), what is the primary factor that contributes to thrombocytopenia?

<p>Increased consumption of platelets by thrombus formation. (B)</p> Signup and view all the answers

What is a unique laboratory finding that is highly suggestive of DIC?

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

What is the main concern associated with massive transfusion syndrome?

<p>Dilution of clotting factors and platelets in the transfused blood. (C)</p> Signup and view all the answers

In Glanzmann thrombasthenia, what is the specific deficiency that disrupts platelet aggregation?

<p>Glycoprotein IIb and IIIa (D)</p> Signup and view all the answers

Which of the following disorders is characterized by larger platelets and a deficiency in glycoprotein Ib?

<p>Bernard-Soulier syndrome (B)</p> Signup and view all the answers

What is the common treatment approach for all the platelet function disorders discussed in the text?

<p>Platelet transfusion (D)</p> Signup and view all the answers

Which of these components is NOT involved in the formation of a stable blood clot?

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

What is the primary function of the platelet plug in hemostasis?

<p>To provide a temporary seal over the damaged vessel (B)</p> Signup and view all the answers

Which phase of hemostasis is responsible for the activation of coagulation factors?

<p>Coagulation phase (C)</p> Signup and view all the answers

What is the role of thromboxane A2 in hemostasis?

<p>To contract the vessel wall, reducing blood flow (B)</p> Signup and view all the answers

What is the relationship between the platelet plug and the fibrin mesh in hemostasis?

<p>The platelet plug forms before the fibrin mesh (B)</p> Signup and view all the answers

Which of these factors contribute to the formation of a stable blood clot?

<p>Activation of clotting factors (A)</p> Signup and view all the answers

What is the primary event initiating the vascular phase of hemostasis?

<p>Exposure of collagen to circulating platelets (A)</p> Signup and view all the answers

The activation of platelets is triggered by

<p>Exposure to collagen (B)</p> Signup and view all the answers

Which of the following is NOT a common symptom associated with vascular fragility due to Type III collagen deficiency?

<p>Swelling of the lymph nodes (C)</p> Signup and view all the answers

Which of the following is a life-threatening complication associated with vascular fragility?

<p>Aneurysm rupture (D)</p> Signup and view all the answers

What is the underlying cause of vascular fragility in Scurvy?

<p>Reduced collagen synthesis (C)</p> Signup and view all the answers

Which of the following conditions is characterized by IgA-mediated vasculitis?

<p>Henoch-Schonlein syndrome (D)</p> Signup and view all the answers

In which of the following conditions is purpura primarily observed in the forearms and hands?

<p>Senile purpura (C)</p> Signup and view all the answers

Which of the following statements accurately describes the cause of vascular fragility in senile purpura?

<p>Atrophy of supportive tissues (C)</p> Signup and view all the answers

Which of the following is NOT a typical manifestation of Henoch-Schonlein syndrome?

<p>Elevated white blood cell count (B)</p> Signup and view all the answers

Which of the following statements is TRUE about simple bruising?

<p>It is a benign disorder with no clinical consequence (D)</p> Signup and view all the answers

Flashcards

Hemostasis

The process that prevents and stops bleeding, maintaining blood in a fluid state.

Vascular Phase

The first phase of hemostasis, involving vascular damage and exposure of platelets.

Platelet Phase

The second phase where platelets adhere to the site of injury, forming a temporary plug.

Coagulation Phase

The phase characterized by the formation of a stable blood clot through fibrin mesh.

Signup and view all the flashcards

Fibrinolytic Phase

The final phase where the blood clot is dissolved after the vessel is healed.

Signup and view all the flashcards

Activated Platelets

Platelets that change shape and release chemicals to promote clotting when they encounter collagen.

Signup and view all the flashcards

Thromboxane A2

A chemical released by activated platelets that constricts blood vessels to reduce blood flow.

Signup and view all the flashcards

ADP in Hemostasis

A molecule released by activated platelets that helps recruit more platelets to the site of injury.

Signup and view all the flashcards

Pathogenesis of ITP

The mechanism causing Immune Thrombocytopenic Purpura involves antibody sensitization and early platelet destruction.

Signup and view all the flashcards

Chronic ITP Symptoms

Common symptoms include petechiae, bruising, and mucosal bleeding due to very low platelet count.

Signup and view all the flashcards

Acute ITP Characteristics

Affects mainly children; usually follows infections like chickenpox, characterized by sudden onset.

Signup and view all the flashcards

Diagnosis of ITP

Diagnosis often involves a platelet count of 10-50 x 10^9/l and checking bone marrow for megakaryocytes.

Signup and view all the flashcards

Drug-Induced Immune Thrombocytopenia

This occurs when drugs create antibodies that target platelets, causing thrombocytopenia.

Signup and view all the flashcards

Type III collagen

A type of collagen found in extensible connective tissues providing strength and elasticity.

Signup and view all the flashcards

Purpura

Purple discolorations on the skin caused by small blood vessel bleeding.

Signup and view all the flashcards

Aneurysms

Abnormal bulging in blood vessels that can lead to rupture.

Signup and view all the flashcards

Senile purpura

Bruising in the elderly due to atrophy of supportive tissues in blood vessels.

Signup and view all the flashcards

Henoch–Schonlein syndrome

An IgA-mediated vasculitis in children, causing purpura and joint swelling post-infection.

Signup and view all the flashcards

Scurvy

A Vitamin C deficiency causing reduced collagen synthesis and vascular fragility.

Signup and view all the flashcards

Vascular fragility

Weakness in blood vessels leading to easily causing bleeding or bruising.

Signup and view all the flashcards

Acquired vascular defects

Conditions leading to vascular bleeding due to external factors or illnesses.

Signup and view all the flashcards

Inherited Disorders

Disorders passed genetically from parents to offspring.

Signup and view all the flashcards

Acquired Disorders

Disorders developed due to environmental factors or life events.

Signup and view all the flashcards

Vascular Bleeding Disorders

Conditions related to abnormal bleeding due to blood vessel issues.

Signup and view all the flashcards

Hereditary Hemorrhagic Telangiectasia (HHT)

A genetic disorder causing abnormal blood vessel formation leading to bleeding.

Signup and view all the flashcards

Autosomal Dominant Disorders

Genetic disorders requiring only one mutated copy of a gene from a parent to express.

Signup and view all the flashcards

Telangiectasia

Dilated microvascular swellings causing small red lesions on skin or mucous membranes.

Signup and view all the flashcards

Arteriovenous Malformation (AVM)

An abnormal connection between arteries and veins, potentially leading to serious complications.

Signup and view all the flashcards

Iron Deficiency Anemia (IDA)

A condition resulting from insufficient iron leading to reduced hemoglobin and anemia.

Signup and view all the flashcards

t-PA

Tissue plasminogen activator that helps dissolve clots.

Signup and view all the flashcards

Vessel Wall Integrity

The condition of blood vessel walls affecting bleeding control.

Signup and view all the flashcards

Platelets

Cell fragments that help form blood clots.

Signup and view all the flashcards

Clotting Factors

Proteins in the blood that help control bleeding.

Signup and view all the flashcards

Fibrinolytic Pathway

The process that breaks down fibrin, aiding clot removal.

Signup and view all the flashcards

Thrombocytopenia

A condition of low platelet count leading to abnormal bleeding.

Signup and view all the flashcards

Easy Bruising

A sign of various bleeding disorders indicating fragile blood vessels.

Signup and view all the flashcards

Von Willebrand Disease

An inherited bleeding disorder due to lack of von Willebrand factor.

Signup and view all the flashcards

Petechiae

Small red or purple spots on the body caused by bleeding.

Signup and view all the flashcards

Thrombotic Thrombocytopenic Purpura (TTP)

A disorder caused by ADAMTS-13 deficiency leading to excessive platelet aggregation and microthrombi formation.

Signup and view all the flashcards

Caspase Deficiency (ADAMTS-13)

A deficiency causing lack of breakdown of von Willebrand factor, resulting in increased platelet aggregation.

Signup and view all the flashcards

Schistocytes

Fragmented red blood cells typically seen on blood smear in conditions like TTP.

Signup and view all the flashcards

Disseminated Intravascular Coagulation (DIC)

A serious condition characterized by increased platelet consumption and elevated D-dimer levels.

Signup and view all the flashcards

D-dimer

A fibrin degradation product elevated in DIC, indicating thrombus formation.

Signup and view all the flashcards

Glanzmann Thrombasthenia

A hereditary disorder where there is a deficiency of glycoproteins IIb and IIIa, leading to impaired platelet aggregation.

Signup and view all the flashcards

Bernard-Soulier Syndrome

A platelet function disorder marked by larger platelets and a deficiency in glycoprotein Ib, disrupting adhesion.

Signup and view all the flashcards

Storage Pool Disease

A condition with deficiency of dense granules resulting in impaired release of ADP and poor platelet aggregation.

Signup and view all the flashcards

Study Notes

Platelet and Coagulation Hemostasis

  • Hemostasis is the process of stopping blood flow from a damaged blood vessel.
  • It involves the cellular and protein-based systems to form a stable blood clot.
  • The clot seals up the wound to prevent further blood loss.

Hemostasis: General Concept

  • Hemostasis has three main stages: a vascular phase, a platelet phase, and a coagulation phase.

  • In the vascular phase, vasoconstriction reduces blood flow to the damaged area. Platelets are activated.

  • In the platelet phase, platelets adhere to the damaged vessel wall, forming a plug.

  • Platelet aggregation occurs, stabilizing the plug with the help from the release of thromboxane A2 (vasoconstrictor) & Adenosine Diphospahte (ADP) from activated platelets.

  • In the coagulation phase, a cascade of clotting factors leads to fibrin formation.

  • The fibrin mesh stabilizes the platelet plug forming a stable blood clot.

Normal Hemostasis

  • Vascular phase: Vessel wall damage exposes subendothelial substances (collagen)
  • Platelet phase: Activated circulating platelets adhere to collagen and aggregate (platelet plug).
  • Coagulation phase: A complex cascade of coagulation factors converts fibrinogen to fibrin, forming a stable clot.
  • Fibrinolytic phase: Clot dissolution and vessel repair

Coagulation Phase: Key Points

  • There are intrinsic and extrinsic pathways that work in a cascade to activate clotting factors.
  • Extrinsic pathway: Initiated by tissue factor (TF) exposure from damaged tissue.
  • Intrinsic pathway: Initiated by blood vessel damage, activation of factor XII.
  • Common pathway: Convergence point of the intrinsic and extrinsic pathways.
  • Coagulation factors are inactive proteins, with active forms denoted by lowercase 'a'
  • This cascade culminates in the activation of thrombin that converts fibrinogen to fibrin to form a fibrin mesh.
  • This fibrin mesh stabilizes the platelet plug and forms a stable blood clot

Coagulation Cascade: Complex Pathways

  • Intrinsic pathway (contact activation): Activates through contact with exposed collagen or subendothelial tissue.
  • Extrinsic pathway (tissue factor): Begins with the activation of factor VII by tissue factor exposed at the injury site.
  • Common pathway: Convergence point of intrinsic and extrinsic pathways, leading to thrombin formation and fibrin clot.

Important Notes

  • Coagulation factors are numbered using Roman numerals (e.g., factor VIII).
  • The active forms of factors end in 'a' (e.g., factor VIIa).
  • Factor VIII is a co-factor of FIXa, forming the "tenase" complex, which activates factor X.

Coagulation Phase: Simplified

  • Diagram showing the intrinsic and extrinsic pathways leading to fibrin clot formation with the common pathway.

Coagulation Phase

  • Thrombin converts fibrinogen into fibrin monomers, which aggregate into a fibrin polymer (mesh).
  • Factor XIII stabilizes the fibrin mesh to create the strong blood clot.

Fibrinolytic Phase

  • This phase breaks up the clot to allow for vessel repair after clotting.
  • Anticoagulant mechanisms are activated as needed for the dissolution and repair.
  • Plasmin, produced from plasminogen, breaks down fibrin.

Factors Affecting Hemostasis

  • Vessel wall integrity is essential for normal hemostasis.
  • Adequate numbers of functional platelets are needed to stop bleeding and maintain health.
  • Adequate levels of clotting factors for clot formation and stability are necessary.
  • Efficient fibrinolytic pathways are needed to break down the clot and allow repair.

Platelet Phase

  • Activated platelets stick to damaged vessel walls (adherence), followed by formation of a platelet plug.
  • Activation of platelets releases substances like thromboxane A2 and ADP, promoting platelet aggregation and vasoconstriction.

Platelet Function

  • Platelets adhering to the damaged vessel wall, leading to activation of platelets.
  • Platelet aggregation (clumping together) to form a plug.
  • Platelets providing surface molecules for coagulation factors of forming stable blood clot

Abnormalities and Bleeding Disorders

  • Causes of abnormal bleeding include vascular disorders, thrombocytopenia, defective platelets, and defective coagulation.
  • Problems with the vascular structure and function, inadequate platelet count, or inability of platelets to function properly - can lead to bleeding disorders.

Vascular Disorders (abnormal bleeding)

  • Easy bruising, petechiae (small spots), purpura (larger spots), and ecchymoses (large bruises).
  • Can be inherited or acquired.
  • Hereditary disorders: include hereditary hemorrhagic telangiectasia (HHT), Ehlers-Danlos syndrome (EDS).
  • Acquired disorders include senile purpura, purpura due to infections (immune complex formation), Henoch-Schönlein purpura, scurvy (Vit C deficiency), and steroid purpura.
  • Complications include nosebleeds (epistaxis), gastrointestinal (GIT) bleeding, and internal organ bleeding.

Thrombocytopenia (low platelet count)

  • Characterized by low platelet count in the blood .
  • Causes include decreased platelet production (megalokaryocyte depression in bone marrow), increased platelet destruction, and increased platelet consumption.
  • Clinical symptoms include bruising, mucosal bleeding, spontaneous bleeding from minor injuries, and significant blood loss during menstruation.

Disorder of Platelet Function

  • Inherited platelet disorders: Glanzmann thrombasthenia, Bernard-Soulier syndrome, storage pool diseases
  • Acquired disorders: Antiplatelet drugs (e.g., aspirin), hyperglobulinemia, myeloproliferative/myelodysplastic disorders, uremia.
  • Common symptoms include prolonged bleeding times regardless of normal platelet counts.

Diagnosis of Platelet Disorders

  • Platelet count (blood test), blood film examination, bone marrow examination, detection of platelet autoantibodies
  • Bleeding time tests assess platelet function.
  • Ristocetin-induced platelet aggregation is helpful in identifying defects of platelet aggregation.
  • Flowcytometry or glycoprotein receptor studies assist in diagnosis of disorders affecting platelet function or receptors.
  • Note:* This is a summary and further research is recommended for a more thorough understanding.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Platelet Hemostasis and Bleeding Disorder 2024 PDF

Description

This quiz covers key aspects of Chronic Immune Thrombocytopenic Purpura (ITP) and Hereditary Hemorrhagic Telangiectasia (HHT). It includes differentiation between chronic and acute ITP, treatment approaches, and characteristics of vascular bleeding disorders. Test your understanding of these medical conditions and their implications.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser