CHAPTER 39: THROMBOTIC DISORDERS AND LABORATORY ASSESSMENT

Question 1

(1) What is the prevalence of venous thrombosis in the United States?

a. 0.01
b. 1 in 1000
c. 10% to 15%
d. 500,000 cases per year

Answer 1

b. 1 in 1000

Question 2

(2) What is thrombophilia?

a. Predisposition to thrombosis secondary to a congenital or acquired disorder
b. Inappropriate triggering of the plasma coagulation system
c. A condition in which clots form uncontrollably
d. Inadequate fibrinolysis

Answer 2

a. Predisposition to thrombosis secondary to a congenital or acquired disorder

Question 3

(3) What acquired thrombosis risk factor is assessed in the hemostasis laboratory?

a. Smoking
b. Immobilization
c. Body mass index
d. Lupus anticoagulant

Answer 3

d. Lupus anticoagulant

Question 4

(4) Trousseau syndrome, a low-grade chronic DIC, is often associated with what type of disorder?

a. Renal disease
b. Hepatic disease
c. Adenocarcinoma
d. Chronic inflammation

Answer 4

c. Adenocarcinoma

Question 5

(5) What is the most common heritable thrombosis risk factor in Caucasians?

a. APC resistance (factor V Leiden mutation)
b. Prothrombin G20210A mutation
c. Antithrombin deficiency
d. Protein S deficiency

Answer 5

a. APC resistance (factor V Leiden mutation)

Question 6

(6) In most LA profiles, what screening test is primary because it detects LA with the fewest interferences?

a. Low-phospholipid PTT
b. DRVVT
c. KCT
d. PT

Answer 6

b. DRVVT

Question 7

(7) A patient with venous thrombosis is tested for protein S deficiency. The protein S activity, antigen, and free antigen all are less than 65%, and the C4bBP level is normal. What type of deficiency is likely?

a. Type I
b. Type II
c. Type III
d. No deficiency is indicated, because the reference range includes 65%.

Answer 7

a. Type I

Question 8

(8) An elevated level of what fibrinolytic system assay is associated with arterial thrombotic risk?

a. PAI-1
b. TPA
c. Factor VIIa
d. Factor XII

Answer 8

a. PAI-1

Question 9

(9) How does lipoprotein (a) cause thrombosis?

a. It causes elevated factor VIII levels.
b. It coats the endothelial lining of arteries.
c. It substitutes for plasminogen or TPA in the forming clot.
d. It contributes additional phospholipid in vivo for formation of the Xase complex

Answer 9

c. It substitutes for plasminogen or TPA in the forming clot.

Question 10

(10) What test may be used to confirm the presence of LA?

a. PT
b. Bethesda titer
c. Antinuclear antibody
d. PTT using high-phospholipid reagent

Answer 10

d. PTT using high-phospholipid reagent

Question 11

(11) What molecular test may be used to confirm APC resistance?

a. Prothrombin G20210A
b. MTHFR 1298
c. MTHFR 677
d. FVL

Answer 11

d. FVL

Question 12

(12) What therapeutic agent may occasionally cause DIC?

a. Factor VIII
b. Factor VIIa
c. Antithrombin concentrate
d. Activated prothrombin complex concentrate

Answer 12

d. Activated prothrombin complex concentrate

Question 13

(13) Which is not a fibrinolysis control protein?

a. Thrombin-activatable fibrinolysis inhibitor
b. Plasminogen activator inhibitor-1
c. a2-antiplasmin
d. D-dimer

Answer 13

d. D-dimer

Question 14

(14) What is the most important application of the quantitative D-dimer test?

a. Diagnose primary fibrinolysis
b. Diagnose liver and renal disease
c. Rule out deep venous thrombosis
d. Diagnose acute myocardial infarction

Answer 14

c. Rule out deep venous thrombosis