hematology- Platelet and Vascular Disorders

Question 1

1. Thrombotic thrombocytopenic purpura (TTP) is
   characterized by:
   A. Prolonged PT
   B. Increased platelet aggregation
   C. Thrombocytosis
   D. Prolonged APTT

Answer 1

B. Increased platelet aggregation

Question 2

2. Thrombocytopenia may be associated with:
   A. Postsplenectomy
   B. Hypersplenism
   C. Acute blood loss
   D. Increased proliferation of pluripotential stem
   cells

Answer 2

B. Hypersplenism

Question 3

3. Aspirin prevents platelet aggregation by inhibiting
   the action of which enzyme?
   A. Phospholipase
   B. Cyclo-oxygenase
   C. Thromboxane A2 synthetase
   D. Prostacyclin synthetase

Answer 3

B. Cyclo-oxygenase

Question 4

4. Normal platelet adhesion depends upon:
   A. Fibrinogen
   B. Glycoprotein Ib
   C. Glycoprotein IIb, IIIa complex
   D. Calcium

Answer 4

B. Glycoprotein Ib

Question 5

5. Which of the following test results is normal in a
   patient with classic von Willebrand’s disease?
   A. Bleeding time
   B. Activated partial thromboplastin time
   C. Platelet count
   D. Factor VIII:C and von Willebrand’s factor
   (VWF) levels

Answer 5

C. Platelet count

Question 6

6. Bernard–Soulier syndrome is associated with:
   A. Decreased bleeding time
   B. Decreased factor VIII assay
   C. Thrombocytopenia and giant platelets
   D. Abnormal platelet aggregation to ADP

Answer 6

C. Thrombocytopenia and giant platelets

Question 7

7. When performing platelet aggregation studies,
   which set of platelet aggregation results would most
   likely be associated with Bernard–Soulier syndrome?
   A. Normal platelet aggregation to collagen, ADP,
   and ristocetin
   B. Normal platelet aggregation to collagen, ADP, and
   epinephrine; decreased aggregation to ristocetin
   C. Normal platelet aggregation to epinephrine and
   ristocetin; decreased aggregation to collagen
   and ADP
   D. Normal platelet aggregation to epinephrine,
   ristocetin, and collagen; decreased aggregation
   to ADP

Answer 7

B. Normal platelet aggregation to collagen, ADP, and
epinephrine; decreased aggregation to ristocetin

Question 8

8. Which set of platelet responses would be most
   likely associated with Glanzmann’s
   thrombasthenia?
   A. Normal platelet aggregation to ADP and
   ristocetin; decreased aggregation to collagen
   B. Normal platelet aggregation to collagen;
   decreased aggregation to ADP and ristocetin
   C. Normal platelet aggregation to ristocetin;
   decreased aggregation to collagen, ADP, and
   epinephrine
   D. Normal platelet aggregation to ADP; decreased
   aggregation to collagen and ristocetin

Answer 8

C. Normal platelet aggregation to ristocetin;
decreased aggregation to collagen, ADP, and
epinephrine

Question 9

9. Which of the following is a characteristic of acute
   immune thrombocytopenic purpura?
   A. Spontaneous remission within a few weeks
   B. Predominantly seen in adults
   C. Nonimmune platelet destruction
   D. Insidious onset

Answer 9

A. Spontaneous remission within a few weeks

Question 10

10. TTP differs from DIC in that:
    A. APTT is normal in TTP but prolonged in DIC
    B. Schistocytes are not present in TTP but are
    present in DIC
    C. Platelet count is decreased in TTP but normal
    in DIC
    D. PT is prolonged in TTP but decreased in DIC

Answer 10

A. APTT is normal in TTP but prolonged in DIC

Question 11

11. Several hours after birth, a baby boy develops
    petechiae and purpura and a hemorrhagic
    diathesis. The platelet count is 18 × 109/L. What is
    the most likely explanation for the low platelet
    count?
    A. Drug-induced thrombocytopenia
    B. Secondary thrombocytopenia
    C. Neonatal alloimmune thrombocytopenia
    D. Neonatal DIC

Answer 11

C. Neonatal alloimmune thrombocytopenia

Question 12

12. Which of the following is associated with
    post-transfusion purpura (PTP)?
    A. Nonimmune thrombocytopenia/alloantibodies
    B. Immune-mediated thrombocytopenia/
    alloantibodies
    C. Immune-mediated thrombocytopenia/
    autoantibodies
    D. Nonimmune-mediated thrombocytopenia/
    autoantibodies

Answer 12

B. Immune-mediated thrombocytopenia/
alloantibodies

Question 13

13. Hemolytic uremic syndrome (HUS) is
    associated with:
    A. Fever, thrombocytosis, anemia, and renal failure
    B. Fever, granulocytosis, and thrombocytosis
    C. Escherichia coli 0157:H7
    D. Leukocytosis and thrombocytosis

Answer 13

C. Escherichia coli 0157:H7

Question 14

14. Storage pool deficiencies are defects of:
    A. Platelet adhesion
    B. Platelet aggregation
    C. Platelet granules
    D. Platelet production

Answer 14

C. Platelet granules

Question 15

15. Lumi-aggregation measures:
    A. Platelet aggregation only
    B. Platelet aggregation and ATP release
    C. Platelet adhesion
    D. Platelet glycoprotein Ib

Answer 15

B. Platelet aggregation and ATP release

Question 16

16. Neurological findings may be commonly
    associated with which of the following disorders?
    A. HUS
    B. TTP
    C. ITP
    D. PTP

Answer 16

B. TTP

Question 17

17. Which of the following is correct regarding
    acquired thrombotic thrombocytopenic purpura?
    A. Autoimmune disease
    B. Decreased VWF
    C. Decreased platelet aggregation
    D. Decreased platelet adhesion

Answer 17

A. Autoimmune disease

Question 18

18. Hereditary hemorrhagic telangiectasia is a
    disorder of:
    A. Platelets
    B. Clotting proteins
    C. Fibrinolysis
    D. Connective tissue

Answer 18

D. Connective tissue

Question 19

19. Which of the following prevents platelet
    aggregation?
    A. Thromboxane A2
    B. Thromboxane B2
    C. Prostacyclin
    D. Antithrombin

Answer 19

C. Prostacyclin

Question 20

20. Which defect characterizes Gray’s syndrome?
    A. Platelet adhesion defect
    B. Dense granule defect
    C. Alpha granule defect
    D. Coagulation defect

Answer 20

C. Alpha granule defect

Question 21

21. The P2Y12 ADP receptor agonist assay may be
    used to monitor platelet aggregation inhibition to
    which of the following drugs?
    A. Warfarin
    B. Heparin
    C. LMWH
    D. Clopidogrel (Plavix)

Answer 21

D. Clopidogrel (Plavix)

Question 22

22. Which of the following instruments can be used to
    evaluate platelet function?
    A. Platelet aggregometer
    B. VerifyNow
    C. PFA-100
    D. All of the above

Answer 22

D. All of the above

Question 23

23. Which of the following platelet aggregating agents
    demonstrates a monophasic aggregation curve
    when used in optimal concentration?
    A. Thrombin
    B. Collagen
    C. Adenosine diphosphate (ADP)
    D. Epinephrine

Answer 23

B. Collagen