Question 1

Regarding assays used to diagnose HIT:

Accepted Answer

A)  They are so reliable that a negative result absolutely excludes the diagnosis of HIT. 
B)  Functional assays require the use of patient serum and reagent platelets known to react to HIT sera. 
C)  Functional assays require the use of patient platelets and reagent sera known to react to HIT platelets. 
D)  A and B 
E)  A and C 
A)  They are so reliable that a negative result absolutely excludes the diagnosis of HIT. 
B)  Functional assays require the use of patient serum and reagent platelets known to react to HIT sera. 
C)  Functional assays require the use of patient platelets and reagent sera known to react to HIT platelets. 
D)  A and B 
E)  A and C

Question 2

The PT evaluates the __________ pathway of coagulation.

Accepted Answer

A)  Intrinsic 
B)  Extrinsic 
C)  Common 
D)  All of the above 
E)  None of the above 
A)  Intrinsic 
B)  Extrinsic 
C)  Common 
D)  All of the above 
E)  None of the above

Question 3

All of the following are true about low-molecular-weight heparin therapy except:

Accepted Answer

A)  It can be easier for both the physician and patient and therapeutic monitoring is not always required. 
B)  It can be given subcutaneously, and patients can administer it to themselves. 
C)  It is much less expensive than unfractionated heparin therapy and never causes HIT. 
D)  If monitoring is required, it cannot be monitored via the APTT. 
E)  It requires monitoring by a target concentration strategy. 
A)  It can be easier for both the physician and patient and therapeutic monitoring is not always required. 
B)  It can be given subcutaneously, and patients can administer it to themselves. 
C)  It is much less expensive than unfractionated heparin therapy and never causes HIT. 
D)  If monitoring is required, it cannot be monitored via the APTT. 
E)  It requires monitoring by a target concentration strategy.

Question 4

Which laboratory test is used to monitor oral anticoagulant (warfarin) therapy?

Accepted Answer

A)  APTT 
B)  PT 
C)  TT 
D)  Fibrinogen 
E)  None of the above 
A)  APTT 
B)  PT 
C)  TT 
D)  Fibrinogen 
E)  None of the above

Question 5

There is increased risk of thrombosis during pregnancy because of all of the following factors except:

Accepted Answer

A)  Significant decline in plasma levels of free and total protein S 
B)  Increased production of most procoagulant proteins 
C)  Absorption of activated protein C from the mother by the fetus 
D)  The placenta is rich in tissue factor that may produce increased thrombin. 
E)  Mechanical factors such as venous stasis of the lower extremities caused by the gravid uterus and trauma to pelvic veins during delivery 
A)  Significant decline in plasma levels of free and total protein S 
B)  Increased production of most procoagulant proteins 
C)  Absorption of activated protein C from the mother by the fetus 
D)  The placenta is rich in tissue factor that may produce increased thrombin. 
E)  Mechanical factors such as venous stasis of the lower extremities caused by the gravid uterus and trauma to pelvic veins during delivery

Question 6

What is the target of the anticoagulant mechanism of heparin?

Accepted Answer

A)  Thrombin inhibition 
B)  Thrombin synthesis 
C)  Plasmin inhibition 
D)  Plasmin synthesis 
E)  None of the above 
A)  Thrombin inhibition 
B)  Thrombin synthesis 
C)  Plasmin inhibition 
D)  Plasmin synthesis 
E)  None of the above

Question 7

Advantages of the APTT over the anti-factor Xa chromogenic assay for monitoring intravenous heparin therapy include all of the following except:

Accepted Answer

A)  The technique is quick, familiar, and easy for laboratorians. 
B)  It is inexpensive. 
C)  It correlates in a linear fashion, across many patient samples, with the actual concentration (U/mL) of heparin in the patient's plasma. 
D)  It reflects the anticoagulant activity of the heparin in the patient's plasma. 
A)  The technique is quick, familiar, and easy for laboratorians. 
B)  It is inexpensive. 
C)  It correlates in a linear fashion, across many patient samples, with the actual concentration (U/mL) of heparin in the patient's plasma. 
D)  It reflects the anticoagulant activity of the heparin in the patient's plasma.

Question 8

The laboratory's algorithm for excluding or diagnosing aPL syndrome may include the following except:

Accepted Answer

A)  Platelet neutralization test 
B)  Dilute Russell viper venom time 
C)  Anticardiolipin ELISA 
D)  t-PA assay 
E)  APTT mixing study 
A)  Platelet neutralization test 
B)  Dilute Russell viper venom time 
C)  Anticardiolipin ELISA 
D)  t-PA assay 
E)  APTT mixing study

Question 9

In the activated partial thromboplastin time (APTT)-based screening assay for activated protein C resistance (APC-R), which situation is consistent with a normal result (i.e., the patient does not have APC-R)?

Accepted Answer

A)  Patient clot time with added APC is longer than the patient clot time without added APC. 
B)  Patient clot time with added APC is shorter than patient clot time without added APC. 
C)  Patient clot time with added APC is the same as patient clot time without added APC. 
A)  Patient clot time with added APC is longer than the patient clot time without added APC. 
B)  Patient clot time with added APC is shorter than patient clot time without added APC. 
C)  Patient clot time with added APC is the same as patient clot time without added APC.

Question 10

Which of the following is/are affected by the vitamin K antagonist warfarin, which is used for oral anticoagulant therapy?

Accepted Answer

A)  Factor XII 
B)  Protein C 
C)  Protein S 
D)  A and B 
E)  B and C 
A)  Factor XII 
B)  Protein C 
C)  Protein S 
D)  A and B 
E)  B and C

Question 11

Warfarin is used clinically for the prevention of all except:

Accepted Answer

A)  Deep venous thrombosis 
B)  Pulmonary embolism 
C)  Bleeding after tooth extraction 
D)  Acute myocardial infarction 
E)  Arterial emboli originating from the heart and causing stroke 
A)  Deep venous thrombosis 
B)  Pulmonary embolism 
C)  Bleeding after tooth extraction 
D)  Acute myocardial infarction 
E)  Arterial emboli originating from the heart and causing stroke

Question 12

Which statement is true regarding monitoring anticoagulant therapy in patients with a LA?

Accepted Answer

A)  If the patient's PT and international normalized ratio (INR) were within normal range before starting warfarin, then the INR can be used for therapeutic monitoring. 
B)  Because the APTT is prolonged in people with LA, the PT has to be used to monitor heparin therapy. 
C)  Because the patient has an LA, if he or she is receiving warfarin therapy, an INR of no more than 2.0 is adequate. 
D)  If the patient is receiving warfarin, then a chromogenic factor X assay may be needed. If the patient is receiving heparin, then a chromogenic anti-factor Xa (heparin assay) should be used if monitoring is required. 
E)  The physician should use his or her best judgment regarding dosing of anticoagulants because it is impossible to monitor anticoagulant therapy in people with LA. 
A)  If the patient's PT and international normalized ratio (INR) were within normal range before starting warfarin, then the INR can be used for therapeutic monitoring. 
B)  Because the APTT is prolonged in people with LA, the PT has to be used to monitor heparin therapy. 
C)  Because the patient has an LA, if he or she is receiving warfarin therapy, an INR of no more than 2.0 is adequate. 
D)  If the patient is receiving warfarin, then a chromogenic factor X assay may be needed. If the patient is receiving heparin, then a chromogenic anti-factor Xa (heparin assay) should be used if monitoring is required. 
E)  The physician should use his or her best judgment regarding dosing of anticoagulants because it is impossible to monitor anticoagulant therapy in people with LA.

Question 13

Thrombin binds to platelets at low concentration to initiate:

Accepted Answer

A)  Shape change 
B)  Secretion 
C)  Aggregation 
D)  All of the above 
E)  None of the above 
A)  Shape change 
B)  Secretion 
C)  Aggregation 
D)  All of the above 
E)  None of the above

Question 14

Which function(s) of thrombin cease(s) to occur when thrombin is bound to thrombomodulin?

Accepted Answer

A)  Activation of platelets 
B)  Activation of factors V, VIII, and XIII 
C)  Cleavage of fibrinogen 
D)  All of the above 
E)  None of the above 
A)  Activation of platelets 
B)  Activation of factors V, VIII, and XIII 
C)  Cleavage of fibrinogen 
D)  All of the above 
E)  None of the above

Question 15

Which of the following clinical features is not significant when evaluating a patient with suspected thrombophilia?

Accepted Answer

A)  History of recurrent fetal loss 
B)  Age at which thrombotic event occurred 
C)  History of myocardial infection (MI) 
D)  Chemotherapy 
E)  Height 
A)  History of recurrent fetal loss 
B)  Age at which thrombotic event occurred 
C)  History of myocardial infection (MI) 
D)  Chemotherapy 
E)  Height

Question 16

What is the target INR for oral anticoagulant therapy in the treatment of venous thrombosis (except possibly patients with LA)?

Accepted Answer

A)  2.0-3.0 
B)  3.0-4.5 
C)  1.0-2.0 
D)  3.0-4.0 
E)  None of the above 
A)  2.0-3.0 
B)  3.0-4.5 
C)  1.0-2.0 
D)  3.0-4.0 
E)  None of the above

Question 17

What is the usual treatment for patients presenting with deep venous thrombosis?

Accepted Answer

A)  Administration of oral anticoagulant (warfarin) followed by heparin therapy 
B)  Administration of lupus anticoagulants followed by heparin therapy 
C)  Administration of intravenous heparin, followed by several months of oral anticoagulant (warfarin) therapy 
D)  All of the above 
E)  None of the above 
A)  Administration of oral anticoagulant (warfarin) followed by heparin therapy 
B)  Administration of lupus anticoagulants followed by heparin therapy 
C)  Administration of intravenous heparin, followed by several months of oral anticoagulant (warfarin) therapy 
D)  All of the above 
E)  None of the above

Question 18

Studies that should be performed before administering fibrinolytic therapy include:

Accepted Answer

A)  PT 
B)  APTT 
C)  Complete blood count (CB
C)  with platelet count 
D)  Fibrinogen assay 
E)  All of the above 
A)  PT 
B)  APTT 
C)  Complete blood count (CB
C)  with platelet count 
D)  Fibrinogen assay 
E)  All of the above

Question 19

The INR is calculated by:

Accepted Answer

A)  Patient value in seconds divided by control value in seconds 
B)  Patient value in seconds divided by the mean of the reference range in seconds 
C)  Control value in seconds divided by patient value in seconds 
D)  Patient value in minutes divided by mean of the reference range in minutes, raised to the ISI 
E)  Patient value in seconds divided by mean of the reference range in seconds, raised to the ISI 
A)  Patient value in seconds divided by control value in seconds 
B)  Patient value in seconds divided by the mean of the reference range in seconds 
C)  Control value in seconds divided by patient value in seconds 
D)  Patient value in minutes divided by mean of the reference range in minutes, raised to the ISI 
E)  Patient value in seconds divided by mean of the reference range in seconds, raised to the ISI

Question 20

Which of the following is/are true regarding HIT?

Accepted Answer

A)  If a patient is suspected of having HIT, it is safe for the doctor to wait until he or she has the results of a HIT assay before stopping all of the patient's exposure to heparin. 
B)  Patients with HIT should not be given any other anticoagulants since they are thrombocytopenic. 
C)  All patients with antibodies to heparin-platelet factor 4 (PF4) complexes have HIT. 
D)  The most important step in preventing or limiting thrombosis in patients with HIT is stopping all exposure to heparin. 
E)  Only unfractionated heparin is associated with HIT. 
A)  If a patient is suspected of having HIT, it is safe for the doctor to wait until he or she has the results of a HIT assay before stopping all of the patient's exposure to heparin. 
B)  Patients with HIT should not be given any other anticoagulants since they are thrombocytopenic. 
C)  All patients with antibodies to heparin-platelet factor 4 (PF4) complexes have HIT. 
D)  The most important step in preventing or limiting thrombosis in patients with HIT is stopping all exposure to heparin. 
E)  Only unfractionated heparin is associated with HIT.

Exam 28: Introduction to Thrombosis and Anticoagulant Therapy

Regarding assays used to diagnose HIT:

The PT evaluates the __________ pathway of coagulation.

All of the following are true about low-molecular-weight heparin therapy except:

Which laboratory test is used to monitor oral anticoagulant (warfarin) therapy?

There is increased risk of thrombosis during pregnancy because of all of the following factors except:

What is the target of the anticoagulant mechanism of heparin?

Advantages of the APTT over the anti-factor Xa chromogenic assay for monitoring intravenous heparin therapy include all of the following except:

The laboratory's algorithm for excluding or diagnosing aPL syndrome may include the following except:

In the activated partial thromboplastin time (APTT)-based screening assay for activated protein C resistance (APC-R), which situation is consistent with a normal result (i.e., the patient does not have APC-R)?

Which of the following is/are affected by the vitamin K antagonist warfarin, which is used for oral anticoagulant therapy?

Warfarin is used clinically for the prevention of all except:

Which statement is true regarding monitoring anticoagulant therapy in patients with a LA?

Thrombin binds to platelets at low concentration to initiate:

Which function(s) of thrombin cease(s) to occur when thrombin is bound to thrombomodulin?

Which of the following clinical features is not significant when evaluating a patient with suspected thrombophilia?

What is the target INR for oral anticoagulant therapy in the treatment of venous thrombosis (except possibly patients with LA)?

What is the usual treatment for patients presenting with deep venous thrombosis?

Studies that should be performed before administering fibrinolytic therapy include:

The INR is calculated by:

Which of the following is/are true regarding HIT?

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

Filters