1. Which of the following disorders of coagulation or conditions is associated with thrombosis rather than bleeding?
A. von Willebrand disease
C. Factor V Leiden mutation
D. Immune thrombocytopenic purpura
The correct answer is C. The other choices are all associated with bleeding and not thrombosis. Note that factor V deficiency and the factor V Leiden mutation are associated with bleeding and thrombosis, respectively.
2. Which of the following conditions or disorders is not associated with deficiencies of multiple coagulation factors?
D. Disseminated intravascular coagulation (DIC)
The correct answer is A. Hemophilia A is a deficiency of only factor VIII. Vitamin K deficiency produces deficiencies in factors II, VII, IX, and X. Liver disease, when severe, produces some decrease in all factors from baseline, except factor VIII. DIC when severe can also produce deficiencies of most of the coagulation factors, including factor VIII.
3. All of the following are quantitative platelet disorders. One of them is immune mediated, that is, involves an antibody that binds to platelets. Identify the immune-mediated thrombocytopenia.
A. Disseminated intravascular coagulation (DIC)
B. Hemolytic uremic syndrome (HUS)
C. Posttransfusion purpura
D. Thrombotic thrombocytopenic purpura
The correct answer is C. All of the others are thrombocytopenias in which the platelets are lost by a consumptive process within the circulation. For posttransfusion purpura, in more than 90% of cases, there is an antibody directed against the platelet antigen known as HPA-1a.
4. Of the choices below, three represent quantitative platelet disorders and one represents a qualitative platelet disorder. Identify the qualitative platelet disorder characterized by defective binding of platelets to Fibrinogen.
A. Glanzmann thrombasthenia
B. Immune thrombocytopenic purpura
D. Essential thrombocythemia
The correct answer is A. Qualitative platelet disorders are associated with a normal platelet count but impaired platelet function. Choices B and C are thrombocytopenic disorders. Choice D is a disorder with an increased number of platelet in the circulation.
5. A patient is known to have a congenital deficiency of a coagulation factor. The patient presents with a normal prothrombin time ...