Thrombocytopenia and Immune Thrombocytopenic Purpura (ITP)

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What is the primary pathogenic mechanism in acquired TTP?

Autoantibody against ADAMTS 13 (correct)

Deficiency of metalloprotease ADAMTS 13

E.coli O157:H7 toxin-induced endothelial damage

Activation of the coagulation cascade

Which of the following is NOT a characteristic feature of TTP?

Thrombocytopenia

Acute renal failure (correct)

Fever

Transient neurologic deficits

What is the primary pathogenic mechanism in HUS?

Deficiency of metalloprotease ADAMTS 13

E.coli O157:H7 toxin-induced endothelial damage (correct)

Autoantibody against ADAMTS 13

Activation of the coagulation cascade

Which laboratory test is typically normal in TTP and HUS?

Prothrombin time (PT) Signup and view all the answers

What is the primary treatment for TTP?

Immunosuppressive agents Signup and view all the answers

Which of the following is a key difference between TTP and HUS?

Presence of neurological symptoms Signup and view all the answers

What is the primary method used to diagnose von Willebrand disease?

Using the ristocetin platelet agglutination test Signup and view all the answers

What is the mechanism behind vWF-mediated platelet agglutination during the ristocetin test?

Formation of interplatelet bridges Signup and view all the answers

What characterizes type IIA von Willebrand disease?

Normal multimers but rapid removal from circulation Signup and view all the answers

What is primarily affected in hemophilia A?

Factor VIII activity Signup and view all the answers

In hemophilia A, what level of factor VIII activity defines severe cases?

Activity levels < 1% of normal Signup and view all the answers

What is the X-linked recessive disorder primarily caused by reduced factor VIII activity?

Hemophilia A Signup and view all the answers

Which of the following best describes the pathogenesis of Immune Thrombocytopenic Purpura (ITP)?

Antibodies against platelet membrane glycoproteins IIb/IIIa or Ib/IX complexes Signup and view all the answers

Which of the following statements about splenectomy in ITP is true?

Splenectomy normalizes the platelet count and induces complete remission in more than two-thirds of patients Signup and view all the answers

What is a common finding in the bone marrow of patients with ITP?

Increased numbers of megakaryocytes Signup and view all the answers

Which of the following statements about splenomegaly in ITP is true?

Splenomegaly is not a feature of uncomplicated ITP Signup and view all the answers

Which of the following clinical manifestations is uncommon in ITP?

Intracerebral or subarachnoid hemorrhages Signup and view all the answers

Which of the following statements about the diagnosis of ITP is true?

The diagnosis rests on the clinical features, thrombocytopenia, examination of the marrow, and the exclusion of secondary ITP Signup and view all the answers

What is the main consequence of widespread fibrin deposition within the microcirculation in DIC?

Obstruction leading to ischemia in severely affected or vulnerable organs Signup and view all the answers

Which of the following can trigger DIC according to the text?

Bacterial sepsis Signup and view all the answers

What is the primary pathologic activation related to the depletion of elements required for hemostasis in DIC known as?

Consumptive coagulopathy Signup and view all the answers

What kind of anemia is associated with DIC due to RBC trauma while passing through vessels narrowed by fibrin thrombi?

Microangiopathic hemolytic anemia Signup and view all the answers

Which of the following is NOT a trigger for Disseminated Intravascular Coagulation according to the text?

Normal pregnancy Signup and view all the answers

What causes the secondary release of plasminogen activator in DIC?

Depletion of platelets and clotting factors Signup and view all the answers

What is the primary source of plasma von Willebrand factor (vWF)?

Endothelial cells Signup and view all the answers

What is the primary function of factor VIII in the coagulation pathway?

Activates factor IX Signup and view all the answers

What is the most common inherited bleeding disorder?

von Willebrand disease Signup and view all the answers

What is the primary clinical manifestation of von Willebrand disease?

All of the above Signup and view all the answers

Which subtype of von Willebrand disease is characterized by the selective loss of high-molecular-weight multimers of vWF?

Type II Signup and view all the answers

What is the primary reason why von Willebrand disease is underrecognized?

The diagnosis requires sophisticated tests Signup and view all the answers