Question 1

Which functional assay result is positive for HIT? (high concentration of heparin = 100 U/mL, low concentration = 0.1 U/mL)

Accepted Answer

A)  Platelet aggregation is absent in the saline control and with the high concentration of heparin, but does occur with the low concentration of heparin. 
B)  Platelet aggregation occurs in the saline control and the high and the low concentrations of heparin. 
C)  Platelet aggregation is absent in the saline control but does occur in the high and low concentrations of heparin. 
D)  Platelet aggregation is absent in the saline control and the low concentration of heparin, but does occur in the high concentration of heparin. 
E)  A and D 
A)  Platelet aggregation is absent in the saline control and with the high concentration of heparin, but does occur with the low concentration of heparin. 
B)  Platelet aggregation occurs in the saline control and the high and the low concentrations of heparin. 
C)  Platelet aggregation is absent in the saline control but does occur in the high and low concentrations of heparin. 
D)  Platelet aggregation is absent in the saline control and the low concentration of heparin, but does occur in the high concentration of heparin. 
E)  A and D A

Question 2

A doctor is concerned about the possibility of aPL syndrome in her patient, who had a stroke when she was 23 years old. Which of the following lab results is consistent with aPL syndrome?

Accepted Answer

A)  APTT prolonged but corrects with both an immediate and an incubated mixing study. Dilute Russell viper venom time (dRVVT) within normal range. 
B)  APTT within normal range, dRVVT within normal range, prothrombin time (PT) within normal range, aCL high titer once but normal 6 weeks later. 
C)  APTT prolonged, APTT prolonged on mixing study, normal dRVVT, normal dilute prothrombin time (dPT), APTT corrects with addition of excess phospholipid. The same results occur with repeat testing 8 weeks later. 
D)  Prolonged PT, prolonged APTT, both correct on their respective immediate and incubated mixing studies. 
E)  Normal APTT and dRVVT, prolonged dPT. dPT still prolonged after addition of excess phospholipid. 
A)  APTT prolonged but corrects with both an immediate and an incubated mixing study. Dilute Russell viper venom time (dRVVT) within normal range. 
B)  APTT within normal range, dRVVT within normal range, prothrombin time (PT) within normal range, aCL high titer once but normal 6 weeks later. 
C)  APTT prolonged, APTT prolonged on mixing study, normal dRVVT, normal dilute prothrombin time (dPT), APTT corrects with addition of excess phospholipid. The same results occur with repeat testing 8 weeks later. 
D)  Prolonged PT, prolonged APTT, both correct on their respective immediate and incubated mixing studies. 
E)  Normal APTT and dRVVT, prolonged dPT. dPT still prolonged after addition of excess phospholipid. C

Question 3

Thrombus formation is central to the pathogenesis of all of the following except:

Accepted Answer

A)  Myocardial infarction 
B)  Ischemic stroke 
C)  Hepatitis 
D)  Pulmonary embolism 
E)  Warfarin-induced skin necrosis 
A)  Myocardial infarction 
B)  Ischemic stroke 
C)  Hepatitis 
D)  Pulmonary embolism 
E)  Warfarin-induced skin necrosis C

Question 4

Which laboratory test is used to monitor low-molecular-weight heparin therapy?

Accepted Answer

A)  FDP 
B)  Anti-Xa chromogenic assay 
C)  Thrombin time 
D)  PT 
E)  APTT 
A)  FDP 
B)  Anti-Xa chromogenic assay 
C)  Thrombin time 
D)  PT 
E)  APTT

Question 5

The INR value for plasma depends on the international sensitivity index (ISI) of the __________ used.

Accepted Answer

A)  Controls 
B)  Thromboplastin reagents 
C)  Calibrators 
D)  Thromboplastin reagent and instrument combination 
E)  Instruments 
A)  Controls 
B)  Thromboplastin reagents 
C)  Calibrators 
D)  Thromboplastin reagent and instrument combination 
E)  Instruments

Question 6

As part of a preoperative work up, a patient has a prolonged APTT. Because of this, you are certain that:

Accepted Answer

A)  The patient will bleed excessively during surgery. 
B)  The patient is receiving heparin. 
C)  The patient is therapeutically anticoagulated with warfarin. 
D)  The patient has a LA and is at higher risk for thrombosis than most people while recovering from surgery. 
E)  None of the above; clinical information and additional testing are needed. 
A)  The patient will bleed excessively during surgery. 
B)  The patient is receiving heparin. 
C)  The patient is therapeutically anticoagulated with warfarin. 
D)  The patient has a LA and is at higher risk for thrombosis than most people while recovering from surgery. 
E)  None of the above; clinical information and additional testing are needed.

Question 7

Which type of assay is preferable for initial detection of protein C deficiency but insufficient for complete characterization of the type of deficiency?

Accepted Answer

A)  Chromogenic assay 
B)  Clot-based (functional) assay 
C)  Immunologic assay 
D)  All of the above 
E)  None of the above 
A)  Chromogenic assay 
B)  Clot-based (functional) assay 
C)  Immunologic assay 
D)  All of the above 
E)  None of the above

Question 8

APC-R:

Accepted Answer

A)  Is most often caused by a defect in the factor V gene. 
B)  Is an extremely common cause of thrombophilia in Asian populations. 
C)  Can be detected only by genetic testing, not by any coagulation tests. 
D)  Is only caused by factor V Leiden. 
E)  Goes away when the patient is pregnant. 
A)  Is most often caused by a defect in the factor V gene. 
B)  Is an extremely common cause of thrombophilia in Asian populations. 
C)  Can be detected only by genetic testing, not by any coagulation tests. 
D)  Is only caused by factor V Leiden. 
E)  Goes away when the patient is pregnant.

Question 9

The most popular laboratory test used in monitoring UH therapy is the __________.

Accepted Answer

A)  PT 
B)  APTT 
C)  Thrombin time (TT) 
D)  Fibrinogen degradation product (FDP) 
E)  Anti-Xa assay 
A)  PT 
B)  APTT 
C)  Thrombin time (TT) 
D)  Fibrinogen degradation product (FDP) 
E)  Anti-Xa assay

Question 10

Which integral membrane protein present on the surface of endothelial cells serves as a cofactor for thrombin-mediated activation of protein C?

Accepted Answer

A)  Heparin 
B)  Fibrinogen 
C)  Plasmin 
D)  Thrombomodulin 
E)  None of the above 
A)  Heparin 
B)  Fibrinogen 
C)  Plasmin 
D)  Thrombomodulin 
E)  None of the above

Question 11

Physiologic activation of plasminogen by the extrinsic pathway of coagulation is initiated by the stimulation of endothelial cells and subsequent release of _____________________.

Accepted Answer

A)  Tissue thromboplastin 
B)  t-PA 
C)  Factor XIIa 
D)  All of the above 
E)  None of the above 
A)  Tissue thromboplastin 
B)  t-PA 
C)  Factor XIIa 
D)  All of the above 
E)  None of the above

Question 12

Activated protein C (APC):

Accepted Answer

A)  Cleaves and inactivates factor Va 
B)  Cleaves and activates factor Va 
C)  Is an inhibitor of coagulation 
D)  A and C 
E)  B and C 
A)  Cleaves and inactivates factor Va 
B)  Cleaves and activates factor Va 
C)  Is an inhibitor of coagulation 
D)  A and C 
E)  B and C

Question 13

Activated protein C is capable of degrading which activated plasma factors in the presence of its cofactor protein S?

Accepted Answer

A)  Va and VIIa 
B)  Va and VIIIa 
C)  IIa and Va 
D)  IIIa and IVa 
E)  None of the above 
A)  Va and VIIa 
B)  Va and VIIIa 
C)  IIa and Va 
D)  IIIa and IVa 
E)  None of the above

Question 14

Naturally occurring substances that limit thrombogenesis include antithrombin, heparin cofactor, and __________.

Accepted Answer

A)  Protein S 
B)  Protein C 
C)  Tissue plasminogen activator (t-P
A)  
D)  All of the above 
E)  None of the above 
A)  Protein S 
B)  Protein C 
C)  Tissue plasminogen activator (t-P
A)  
D)  All of the above 
E)  None of the above

Question 15

Which type of protein C deficiency is associated with normal antigenic levels of protein C but low functional activity of protein C?

Accepted Answer

A)  Type I 
B)  Type II 
C)  Type III 
D)  Type IV 
E)  None of the above 
A)  Type I 
B)  Type II 
C)  Type III 
D)  Type IV 
E)  None of the above

Question 16

Why would a patient given only warfarin (oral vitamin K antagonist) therapy initially be at risk for thrombosis rather than bleeding for the first 3 or 4 days of therapy?

Accepted Answer

A)  Factor VIII levels increase initially. 
B)  Factor VII has a short half-life. 
C)  Warfarin is absorbed by the intestine only after several days. 
D)  Protein C and S have short half-lives and decrease sooner than factors II, IX, and X do after beginning therapy. 
E)  None of the above 
A)  Factor VIII levels increase initially. 
B)  Factor VII has a short half-life. 
C)  Warfarin is absorbed by the intestine only after several days. 
D)  Protein C and S have short half-lives and decrease sooner than factors II, IX, and X do after beginning therapy. 
E)  None of the above

Question 17

Which of the following is not a characteristic of thrombin?

Accepted Answer

A)  Cleavage of fibrinogen to form polymerizable fibrin monomers 
B)  Direct lysis of a clot 
C)  Converts factor XIII to an active transglutaminase which then cross-links polymerized fibrin, rendering it insoluble 
D)  Activates factors VIII and V 
E)  None of the above 
A)  Cleavage of fibrinogen to form polymerizable fibrin monomers 
B)  Direct lysis of a clot 
C)  Converts factor XIII to an active transglutaminase which then cross-links polymerized fibrin, rendering it insoluble 
D)  Activates factors VIII and V 
E)  None of the above

Question 18

Which inherited thrombotic disorder may present clinically as neonatal purpura fulminans and with coagulation test results indicative of disseminated intravascular coagulation (DIC)?

Accepted Answer

A)  Homozygous protein C deficiency 
B)  Activated protein C resistance 
C)  Heterozygous protein C deficiency 
D)  Heterozygous protein S deficiency 
E)  None of the above 
A)  Homozygous protein C deficiency 
B)  Activated protein C resistance 
C)  Heterozygous protein C deficiency 
D)  Heterozygous protein S deficiency 
E)  None of the above

Question 19

Which of the following is/are true regarding inherited thrombophilia?

Accepted Answer

A)  The majority of people who carry heterozygous mutations that have been associated with thrombosis do not manifest a thrombotic disease. 
B)  Activated protein C resistance, protein C deficiency, protein S deficiency, and antithrombin deficiency are all examples of inherited thrombophilic disorders. 
C)  Prothrombin nucleotide G20210A mutation, hyperhomocysteinemia, and some forms of dysfibrinogenemia are associated with thrombotic disease. 
D)  A and B only 
E)  A, B, and C 
A)  The majority of people who carry heterozygous mutations that have been associated with thrombosis do not manifest a thrombotic disease. 
B)  Activated protein C resistance, protein C deficiency, protein S deficiency, and antithrombin deficiency are all examples of inherited thrombophilic disorders. 
C)  Prothrombin nucleotide G20210A mutation, hyperhomocysteinemia, and some forms of dysfibrinogenemia are associated with thrombotic disease. 
D)  A and B only 
E)  A, B, and C

Question 20

A reasonable panel of laboratory tests to screen for the more common causes of thrombophilia in a patient with recurrent thrombosis could include any of the following except:

Accepted Answer

A)  Protein C, protein S, and antithrombin functional (activity level) assays 
B)  Screening test for APC resistance 
C)  Two screening tests for lupus anticoagulant, for example, dRVVT and APTT 
D)  vWF assay 
E)  aCL antibody ELISA 
A)  Protein C, protein S, and antithrombin functional (activity level) assays 
B)  Screening test for APC resistance 
C)  Two screening tests for lupus anticoagulant, for example, dRVVT and APTT 
D)  vWF assay 
E)  aCL antibody ELISA

Exam 28: Introduction to Thrombosis and Anticoagulant Therapy

Which functional assay result is positive for HIT? (high concentration of heparin = 100 U/mL, low concentration = 0.1 U/mL)

A doctor is concerned about the possibility of aPL syndrome in her patient, who had a stroke when she was 23 years old. Which of the following lab results is consistent with aPL syndrome?

Thrombus formation is central to the pathogenesis of all of the following except:

Which laboratory test is used to monitor low-molecular-weight heparin therapy?

The INR value for plasma depends on the international sensitivity index (ISI) of the __________ used.

As part of a preoperative work up, a patient has a prolonged APTT. Because of this, you are certain that:

Which type of assay is preferable for initial detection of protein C deficiency but insufficient for complete characterization of the type of deficiency?

APC-R:

The most popular laboratory test used in monitoring UH therapy is the __________.

Which integral membrane protein present on the surface of endothelial cells serves as a cofactor for thrombin-mediated activation of protein C?

Physiologic activation of plasminogen by the extrinsic pathway of coagulation is initiated by the stimulation of endothelial cells and subsequent release of _____________________.

Activated protein C (APC):

Activated protein C is capable of degrading which activated plasma factors in the presence of its cofactor protein S?

Naturally occurring substances that limit thrombogenesis include antithrombin, heparin cofactor, and __________.

Which type of protein C deficiency is associated with normal antigenic levels of protein C but low functional activity of protein C?

Why would a patient given only warfarin (oral vitamin K antagonist) therapy initially be at risk for thrombosis rather than bleeding for the first 3 or 4 days of therapy?

Which of the following is not a characteristic of thrombin?

Which inherited thrombotic disorder may present clinically as neonatal purpura fulminans and with coagulation test results indicative of disseminated intravascular coagulation (DIC)?

Which of the following is/are true regarding inherited thrombophilia?

A reasonable panel of laboratory tests to screen for the more common causes of thrombophilia in a patient with recurrent thrombosis could include any of the following except:

Morphology of Human Blood and Marrow Cells: Hematopoiesis

Bone Marrow

The Red Blood Cell: Structure and Function

Anemia: Diagnosis and Clinical Considerations

Evaluation of Red Blood Cell Morphology and Introduction to Platelet and White Blood Cell Morphology

Iron Metabolism and Hypochromic Anemias

Megaloblastic Anemias

Aplastic Anemia Including Pure Red Cell Aplasia and Congenital Dyserythropoietic Anemia and Paroxysmal Nocturnal Hemoglobinuria

Introduction to Hemolytic Anemias: Intracorpuscular Defects: I Hereditary Defects of the Red Cell Membrane

Hemolytic Anemias: Intracorpuscular Defects: II Hereditary Enzyme Deficiencies

Hemolytic Anemias: Intracorpuscular Defects: III the Hemoglobinopathies

Hemolytic Anemias: Intracorpuscular Defects: Iv Thalassemia

Hemolytic Anemias: Extracorpuscular Defects

Hypoproliferative Anemia: Anemia Associated With Systemic Diseases

Cell Biology, Disorders of Neutrophils, Infectious Mononucleosis, and Reactive Lymphocytosis

Introduction to Leukemia and the Acute Leukemias

Chronic Myeloproliferative Disorders I: Chronic Myelogenous Leukemia

Chronic Myeloproliferative Disorders Ii: Polycythemia Vera, Essential Thrombocythemia, and Idiopathic Myelofibrosis

Myelodysplastic Syndromes

Chronic Lymphocytic Leukemia and Related Lymphoproliferative Disorders

The Lymphomas

Multiple Myeloma and Related Plasma Cell Disorders

Lipid Lysosomal Storage Diseases and Histiocytosis

Introduction to Hemostasis

Disorders of Primary Hemostasis: Quantitative and Qualitative Platelet Disorders and Vascular Disorders

Disorders of Plasma Clotting Factors

Interaction of the Fibrinolytic, Coagulation, and Kinin Systems; Disseminated Intravascular Coagulation; and Related Pathology

Quality Control in the Hematology Laboratory

Body Fluid Examination: the Qualitative, Quantitative, and Morphologic Analysis of Serous, Cerebrospinal, and Synovial Fluids

Hematology Methods

Principles of Automated Differential Analysis

Coagulation Procedures

Applications of Flow Cytometry to Hematology and Hemostasis

Molecular Diagnostic Techniques in Hematopathology

Special Stainscytochemistry

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