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Questions and Answers
What type of bleeding is most commonly associated with defects in blood vessels or platelets?
What type of bleeding is most commonly associated with defects in blood vessels or platelets?
Which of the following is NOT an inherited vascular disorder?
Which of the following is NOT an inherited vascular disorder?
What characterizes thrombocytopenia?
What characterizes thrombocytopenia?
Which of the following is associated with vitamin C deficiency?
Which of the following is associated with vitamin C deficiency?
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What is the risk of bleeding with thrombocytopenia when platelet count drops below 20×10^9/L?
What is the risk of bleeding with thrombocytopenia when platelet count drops below 20×10^9/L?
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Which condition is characterized by purpuric rash and usually follows an acute infection in children?
Which condition is characterized by purpuric rash and usually follows an acute infection in children?
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What is a common symptom of both thrombocytopenia and vascular disorders?
What is a common symptom of both thrombocytopenia and vascular disorders?
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Which of the following may lead to easy bruising in healthy females at childbearing age?
Which of the following may lead to easy bruising in healthy females at childbearing age?
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What is one primary cause of thrombocytopenia related to platelet production?
What is one primary cause of thrombocytopenia related to platelet production?
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Which condition is characterized by autoimmune destruction of platelets?
Which condition is characterized by autoimmune destruction of platelets?
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What characteristic laboratory finding is expected in a patient with chronic ITP?
What characteristic laboratory finding is expected in a patient with chronic ITP?
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What is a non-immune mechanism that leads to increased platelet consumption?
What is a non-immune mechanism that leads to increased platelet consumption?
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Which characteristic is true about the lifespan of platelets in patients with ITP?
Which characteristic is true about the lifespan of platelets in patients with ITP?
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What is a common association with chronic ITP?
What is a common association with chronic ITP?
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In which condition would you expect increased platelet production despite low platelet count?
In which condition would you expect increased platelet production despite low platelet count?
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What is a significant reason for conducting a bone marrow examination in ITP cases?
What is a significant reason for conducting a bone marrow examination in ITP cases?
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Which age group is most commonly affected by acute ITP?
Which age group is most commonly affected by acute ITP?
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What is a common precipitating factor for acute ITP?
What is a common precipitating factor for acute ITP?
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What characterizes the onset of chronic ITP compared to acute ITP?
What characterizes the onset of chronic ITP compared to acute ITP?
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What is the primary pathogenesis mechanism in acute ITP?
What is the primary pathogenesis mechanism in acute ITP?
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Which condition is characterized by widespread activation of the coagulation system leading to platelet consumption?
Which condition is characterized by widespread activation of the coagulation system leading to platelet consumption?
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What underlying defect is present in Thrombotic thrombocytopenic purpura?
What underlying defect is present in Thrombotic thrombocytopenic purpura?
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What is a common clinical history associated with Hemolytic uremic syndrome?
What is a common clinical history associated with Hemolytic uremic syndrome?
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What is a characteristic finding in disseminated intravascular coagulation (DIC)?
What is a characteristic finding in disseminated intravascular coagulation (DIC)?
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What is a common consequence of conditions that cause disseminated intravascular coagulation (DIC)?
What is a common consequence of conditions that cause disseminated intravascular coagulation (DIC)?
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Which condition is NOT typically associated with the development of DIC?
Which condition is NOT typically associated with the development of DIC?
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Which inherited platelet function defect is characterized by giant platelets?
Which inherited platelet function defect is characterized by giant platelets?
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What is the first-line antiplatelet drug that causes an abnormal bleeding time?
What is the first-line antiplatelet drug that causes an abnormal bleeding time?
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Which of the following is considered an acquired platelet function defect?
Which of the following is considered an acquired platelet function defect?
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What typically results from excessive activation of the fibrinolytic system in DIC?
What typically results from excessive activation of the fibrinolytic system in DIC?
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What type of receptor is deficient in Glanzmann's thrombosthenia?
What type of receptor is deficient in Glanzmann's thrombosthenia?
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Which condition can interfere with platelet adhesion due to the presence of paraprotein?
Which condition can interfere with platelet adhesion due to the presence of paraprotein?
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Study Notes
Bleeding Disorders
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Bleeding generally indicates blood vessel rupture, often precipitated by trauma or surgery. Spontaneous bleeding or severe bleeding after minor injuries can signal bleeding disorders.
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Abnormal bleeding can stem from vascular disorders, platelet issues (number or function), or defects in blood clotting.
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Bleeding patterns vary based on the underlying cause. Vessel defects usually lead to skin and mucous membrane bleeding, whereas coagulation defects frequently cause joint and soft tissue bleeding.
Coagulation, Platelets, and Vessels
- A table of findings demonstrates distinctions in bleeding onset and location (e.g., mucosal bleeding, deep hematomas) based on coagulation, platelet, or vessel pathology. Factors like time since trauma, sex of patient, and the presence/type of bleeding (e.g., petechiae, ecchymoses).
Vascular Disorders
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Vascular disorders are conditions characterized by easy bruising, typically involving the blood vessels or perivascular connective tissue. Bleeding in these cases is usually not severe (petichiae, ecchymosis).
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Standard hemophilia tests are usually normal in vascular disorders. Vascular disorders can be inherited or acquired.
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Examples of inherited vascular disorders include hereditary hemorrhagic telangiectasia. Connective tissue disorders such as Ehler-Danlos syndrome are also included.
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Acquired vascular disorders might involve easy bruising, especially in females of childbearing age, or atrophy of supporting tissues (senile purpura), or infections (bacterial, viral, rickettsial). Also consider vitamin c deficiency (scurvy) or long-term steroid therapy.
Thrombocytopenia
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Thrombocytopenia is characterized by abnormally low platelet counts (usually below 100 x 109/L) leading to increased bleeding risk.
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Bleeding associated is typically seen as petechiae (small red dots) and mucosal bleeding. Platelet level helps categorize severity (mild >80 x 109/L, moderate 20-80 x 109/L, severe <20 x 109/L).
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Causes of thrombocytopenia include:
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Platelet production failure (e.g., bone marrow failure, infections, malignancies).
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Increased platelet consumption (e.g., immune thrombocytopenic purpura (ITP), viral infections, drug-induced, post-transfusion purpura, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura).
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Abnormal platelet distribution (e.g., splenomegaly).
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Dilutional loss (e.g., massive blood transfusions).
Idiopathic Immune Thrombocytopenic Purpura (ITP)
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ITP is an autoimmune disorder driven by antibodies that target platelets, leading to their destruction mainly by the spleen's phagocytic cells.
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Acute ITP is common in children, often following infection, while chronic ITP affects adults (15-50 years) and might be associated with other diseases.
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Platelets are removed prematurely and platelet life span is shortened. Megakaryocyte and platelet production is increased.
Diagnosis
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Platelet count is low in most cases, but hemoglobin and white blood cell counts are usually normal, unless iron deficiency anemia or other blood loss is a factor.
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Bone marrow examination may show increased megakaryocytes.
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Testing for antibodies against platelet glycoproteins may be needed.
Acute ITP
- Acute ITP is most prevalent in children, often linked to vaccination or infectious conditions (mononucleosis, chicken pox).
- The disease often resolves spontaneously, but in some cases, it can become chronic.
Chronic ITP
- Chronic ITP is usually idiopathic but can be associated with other medical conditions.
- Chronic ITP leads to the accelerated removal of platelets from the circulation, shortening the platelet lifespan and increased megakaryocyte/platelet production.
Differences in Acute and Chronic ITP
- The table outlines clinical differences between acute and chronic ITP presentation, including peak age, onset, duration, associated factors (including viral infections and vaccinations), pathogenesis, and associated factors, among other aspects.
Treatment
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Treatment of primary/newly diagnosed ITP starts with corticosteroids, IVIG, and RhD immune globulin.
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Second-line treatment involves splenectomy or rituximab for those who do not respond to first-line treatments.
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Third-line treatment targets chronic refractory cases with retreatment of steroids alongside various other medications.
Non-Immune Mediated Platelet Consumption
- This group of disorders involves widespread activation of the coagulation system, leading to excessive platelet and coagulation factor consumption. Microthrombi formation is key to this process.
Thrombotic Thrombocytopenic Purpura (TTP)
- TTP is a disorder characterized by severe platelet consumption and damage to red blood cells due to the accumulation of abnormal von Willebrand factor (vWF), which are usually of large size. The condition results from a deficiency of ADAMTS13.
Hemolytic Uremic Syndrome (HUS)
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HUS is often triggered by infections (primarily from E. coli or other bacteria), characterized by blood vessel damage and consumption of coagulation factors, often affecting the kidneys.
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Other triggers of DIC include sepsis, severe trauma, malignancy, obstetric complications, etc.
Platelet Function Defects
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Inherited platelet function disorders like Bernard-Soulier syndrome result in giant platelets, prolonged bleeding time, and quantitative or qualitative deficiency of blood clotting factors (GP1b, GPIIb/IIIa).
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Other types of acquired platelet function defects include drug-induced effects (e.g., aspirin can inhibit cyclo-oxygenase), uremia, hyperglobulinemia, and conditions involving myeloproliferation/dysplasia.
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Description
Test your knowledge on hematology and bleeding disorders with this quiz. Explore topics such as thrombocytopenia, vascular disorders, and the effects of vitamin deficiencies on blood health. Each question will challenge your understanding of the mechanisms behind these conditions.
