Hematology- Inhibitors, Thrombotic Disorders, and Anticoagulant Drugs Flashcards
- Which characteristic describes antithrombin (AT)?
A. It is synthesized in megakaryocytes
B. It is activated by protein C
C. It is a cofactor of heparin
D. It is a pathological inhibitor of coagulation
C. It is a cofactor of heparin
- Which laboratory test is affected by heparin
therapy?
A. Thrombin time
B. Fibrinogen assay
C. Protein C assay
D. Protein S assay
A. Thrombin time
- An abnormal APTT caused by a pathological
circulating anticoagulant is:
A. Corrected with factor VIII–deficient plasma
B. Corrected with factor IX–deficient plasma
C. Corrected with normal plasma
D. Not corrected with normal plasma
D. Not corrected with normal plasma
- The lupus anticoagulant affects which of the
following tests?
A. Factor VIII assay
B. Factor IX assay
C. VWF assay
D. Phospholipid-dependent assays
D. Phospholipid-dependent assays
- Which statement about Coumadin (warfarin) is
accurate?
A. It is a vitamin B antagonist
B. It is not recommended for pregnant and
lactating women
C. It needs antithrombin as a cofactor
D. APTT test is used to monitor its dosage
B. It is not recommended for pregnant and
lactating women
- Which statement regarding protein C is correct?
A. It is a vitamin K–independent zymogen
B. It is activated by fibrinogen
C. It activates cofactors V and VIII
D. Its activity is enhanced by protein S
D. Its activity is enhanced by protein S
- Which of the following is an appropriate screening
test for the diagnosis of lupus anticoagulant?
A. Thrombin time test
B. Diluted Russell’s viper venom test (DRVVT)
C. D-dimer test
D. FDP test
B. Diluted Russell’s viper venom test (DRVVT)
- Which of the following is most commonly
associated with activated protein C resistance
(APCR)?
A. Bleeding
B. Thrombosis
C. Epistaxis
D. Menorrhagia
B. Thrombosis
- A 50-year-old man has been on heparin for the
past 7 days. Which combination of the tests is
expected to be abnormal?
A. PT and APTT only
B. APTT, TT only
C. APTT, TT, fibrinogen assay
D. PT, APTT, TT
D. PT, APTT, TT
- Which of the following drugs inhibits ADP
mediated platelet aggregation?
A. Heparin
B. Warfarin
C. Aspirin
D. Prasugrel
D. Prasugrel
- Thrombin-thrombomodulin complex is necessary
for activation of:
A. Protein C
B. Antithrombin
C. Protein S
D. Factors V and VIII
A. Protein C
- What test is used to monitor heparin therapy?
A. INR
B. APTT
C. TT
D. PT
B. APTT
- What test is commonly used to monitor warfarin
therapy?
A. INR
B. APTT
C. TT
D. Ecarin time
A. INR
- What clotting factors (cofactors) are inhibited by
protein S?
A. V and X
B. Va and VIIIa
C. VIII and IX
D. VIII and X
B. Va and VIIIa
- Which drug promotes fibrinolysis?
A. Warfarin
B. Heparin
C. Urokinase
D. Aspirin
C. Urokinase
- Diagnosis of lupus anticoagulant is confirmed by
which of the following criteria?
A. Decreased APTT
B. Correction of the APPT by mixing studies
C. Neutralization of the antibody by high
concentration of platelets
D. Confirmation that abnormal coagulation tests are
time and temperature dependent
C. Neutralization of the antibody by high
concentration of platelets
- Which of the following abnormalities is consistent
with the presence of lupus anticoagulant?
A. Decreased APTT/bleeding complications
B. Prolonged APTT/thrombosis
C. Prolonged APTT/thrombocytosis
D. Thrombocytosis/thrombosis
B. Prolonged APTT/thrombosis
- Which of the following is a characteristic of low
molecular weight heparin (LMWH)?
A. Generally requires monitoring
B. Specifically acts on factor Va
C. Has a longer half-life than unfractionated
heparin
D. Can be used as a fibrinolytic agent
C. Has a longer half-life than unfractionated
heparin
- Which of the following tests is most likely to be
abnormal in patients taking aspirin?
A. Platelet morphology
B. Platelet count
C. Bleeding time
D. Prothrombin time
C. Bleeding time
- Which of the following is associated with
antithrombin deficiency?
A. Thrombocytosis
B. Thrombosis
C. Thrombocytopenia
D. Bleeding
B. Thrombosis
- Which of the following may be associated with
thrombotic events?
A. Decreased protein C
B. Increased fibrinolysis
C. Afibrinogenemia
D. ITP
A. Decreased protein C
- Aspirin resistance may be associated with:
A. Bleeding
B. Factor VIII deficiency
C. Thrombosis
D. Thrombocytosis
C. Thrombosis
- A prolonged thrombin time is indicative of which
of the following antithrombotic therapies?
A. Prasugrel
B. Clopidogrel
C. Aspirin
D. Heparin
D. Heparin
- Screening tests for thrombophilia should be
performed on:
A. All pregnant women because of the thrombotic
risk
B. Patients with a negative family history
C. Patients with thrombotic events occurring at a
young age
D. Patients who are receiving anticoagulant therapy
C. Patients with thrombotic events occurring at a
young age
- Prothrombin G20210A is characterized by which
of the following causes and conditions?
A. Single mutation of prothrombin molecule/
bleeding
B. Single mutation of prothrombin molecule/
thrombosis
C. Decreased levels of prothrombin in plasma/
thrombosis
D. Increased levels of prothrombin in plasma/
bleeding
B. Single mutation of prothrombin molecule/
thrombosis
- Factor V Leiden promotes thrombosis by
preventing:
A. Deactivation of factor Va
B. Activation of factor V
C. Activation of protein C
D. Activation of protein S
A. Deactivation of factor Va
- What is the approximate incidence of
antiphospholipid antibodies in the general
population?
A. <1%
B. 2%
C. 10%
D. 20%
B. 2%
- Which of the following laboratory tests is helpful
in the diagnosis of aspirin resistance?
A. APTT
B. PT
C. Platelet count and morphology
D. Platelet aggregation
D. Platelet aggregation
- Which of the following complications may occur
as a result of decreased tissue factor pathway
inhibitor (TFPI)?
A. Increased hemorrhagic episodes
B. Increased thrombotic risk
C. Impaired platelet plug formation
D. Immune thrombocytopenia
B. Increased thrombotic risk
- Factor VIII inhibitors occur in ____________ of
patients with factor VIII deficiency?
A. 40%–50%
B. 30%–40%
C. 25%–30%
D. 10%–20%
D. 10%–20%
- Which therapy and resulting mode of action are
appropriate for the treatment of a patient with a
high titer of factor VIII inhibitors?
A. Factor VIII concentrate to neutralize the
antibodies
B. Recombinant factor VIIa (rVIIa) to activate
factor X
C. Factor X concentrate to activate the common
pathway
D. Fresh frozen plasma to replace factor VIII
B. Recombinant factor VIIa (rVIIa) to activate
factor X
- The Bethesda assay is used for which
determination?
A. Lupus anticoagulant titer
B. Factor VIII inhibitor titer
C. Factor V Leiden titer
D. Protein S deficiency
B. Factor VIII inhibitor titer
- Hyperhomocysteinemia may be a risk factor for:
A. Bleeding
B. Thrombocythemia
C. Thrombosis
D. Thrombocytopenia
C. Thrombosis
- Which drug may be associated with deep venous
thrombosis (DVT)?
A. Aspirin
B. tPA
C. Oral contraceptives
D. Plavix (clopidogrel)
C. Oral contraceptives
- Argatroban may be used as an anticoagulant drug
in patients with:
A. DVT
B. Hemorrhage
C. TTP
D. Thrombocytosis
A. DVT
- Heparin-induced thrombocytopenia (HIT)
results from:
A. Antibodies to heparin
B. Antibodies to platelets
C. Antibodies to PF4
D. Antibodies to heparin-PF4 complex
D. Antibodies to heparin-PF4 complex
- Which laboratory test is used to screen for
activated protein C resistance?
A. Mixing studies with normal plasma
B. Mixing studies with factor-deficient plasma
C. Modified APTT with and without activated
protein C
D. Modified PT with and without activated
protein C
C. Modified APTT with and without activated
protein C
- Ecarin clotting time may be used to monitor:
A. Heparin therapy
B. Warfarin therapy
C. Fibrinolytic therapy
D. Hirudin therapy
D. Hirudin therapy
- Which of the following may interfere with the
activated protein C resistance (APCR) screening
test?
A. Lupus anticoagulant
B. Protein C deficiency
C. Antithrombin deficiency
D. Protein S deficiency
A. Lupus anticoagulant
- Thrombophilia may be associated with which
of the following disorders?
A. Afibrinogenemia
B. Hypofibrinogenemia
C. Factor VIII inhibitor
D. Hyperfibrinogenemia
D. Hyperfibrinogenemia
- Which of the following anticoagulant drugs can be
used in patients with HIT?
A. Warfarin
B. Heparin
C. Aspirin
D. Lepirudin
D. Lepirudin
- Which of the following is the preferred method
to monitor heparin therapy at the point of care
during cardiac surgery?
A. APTT
B. Activated clotting time test (ACT)
C. PT
D. TT
B. Activated clotting time test (ACT)
- Mrs. Smith has the following laboratory results,
and no bleeding history:
APTT: prolonged
APTT results on a 1:1 mixture of the patient’s plasma
with normal plasma:
Preincubation: prolonged APTT
2-hour incubation: prolonged APTT
These results are consistent with:
A. Factor VIII deficiency
B. Factor VIII inhibitor
C. Lupus anticoagulant
D. Protein C deficiency
C. Lupus anticoagulant
- Which test may be used to monitor LMWH
therapy?
A. APTT
B. INR
C. Anti-Xa heparin assay
D. Activated clotting time
C. Anti-Xa heparin assay