PLATELET&VASCULARDISORDERS

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

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

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

Question 4

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

Answer 4

b

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

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

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

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

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

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

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

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

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

Question 14

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

Answer 14

c

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

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

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

Question 18

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

Answer 18

d

Question 19

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

Answer 19

c

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

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

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

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