CHAPTER 37 Flashcards
- The clinical presentation of platelet-related bleeding may include all of the following except:
a. Bruising
b. Nosebleeds
c. Gastrointestinal bleeding
d. Bleeding into the joints
(hemarthroses)
d. Bleeding into the joints
(hemarthroses)
- A defect in GP IIb/IIIa causes:
a. Glanzmann thrombasthenia
b. Bernard-Soulier syndrome
c. Gray platelet syndrome
d. Storage pool disease
a. Glanzmann thrombasthenia
- Patients with Bernard-Soulier syndrome have which of the following laboratory test findings?
a. Abnormal platelet response to
arachidonic acid
b. Abnormal platelet response to
ristocetin
c. Abnormal platelet response to
collagen
d. Thrombocytosis
b. Abnormal platelet response to
ristocetin
- Which of the following is the most common of the hereditary platelet function defects?
a. Glanzmann thrombasthenia
b. Bernard-Soulier syndrome
c. Storage pool defects
d. Multiple myeloma
c. Storage pool defects
- A reduction in thrombin generation in patients with Scott syndrome results from:
a. Defective granule secretion
b. Altered platelet aggregation
c. Altered expression of
phospholipids on the platelet
membrane
d. Deficiency of vitamin K-dependent
clotting factors
c. Altered expression of
phospholipids on the platelet
membrane
- The impaired platelet function in
myeloproliferative neoplasms results from:
a. Abnormally shaped platelets
b. Extended platelet life span
c. Increased procoagulant activity
d. Decreased numbers of a granules
and dense granules
d. Decreased numbers of a granules
and dense granules
- The platelet defect associated with increased paraproteins is:
a. Impaired membrane activation,
owing to protein coating
b. Hypercoagulability, owing to antibody
binding and membrane activation
c. Impaired aggregation, because the
hyperviscous plasma prevents
platelet-endothelium interaction
d. Hypercoagulability, because the
increased proteins bring platelets closer
together, which leads to inappropriate
aggregation
a. Impaired membrane activation,
owing to protein coating
- In uremia, platelet function is impaired by higher than normal levels of:
a. Urea
b. Uric acid
c. Creatinine
d. NO
d. NO
- Thrombocytopenia associated with the use of cardiopulmonary bypass is not caused by:
a. Anti-GP IIb/IIIa antibodies
b. Hemodilution
c. Platelet binding to bypass circuitry
d. Platelet consumption associated with
normal postsurgical hemostatic activity
a. Anti-GP IIb/IIIa antibodies
- A mechanism of antiplatelet drugs targeting GP IIb/IIIa function is:
a. Interference with platelet adhesion to
the subendothelium by blocking of the
collagen binding site
b. Inhibition of transcription of the GP
IIb/IIIa gene
c. Direct binding to GP IIb/IIIa
d. Interference with platelet secretion
c. Direct binding to GP IIb/IIIa
- Aspirin ingestion blocks the synthesis of:
a. Thromboxane A2
b. Ionized calcium
c. Collagen d. ADP
a. Thromboxane A2
- Which is a congenital qualitative platelet
disorder?
a. Senile purpura
b. Ehlers-Danlos syndrome
c. Henoch-Schönlein purpura
d. Waldenström macroglobulinemia
b. Ehlers-Danlos syndrome
- A defect in primary hemostasis (platelet
response to an injury) often results in:
a. Musculoskeletal bleeding
b. Mucosal bleeding
c. Hemarthroses
d. None of the above
b. Mucosal bleeding
- The autosomal dominant disorder associated with decreased platelet production is:
a. Fanconi anemia
b. TAR syndrome
c. May-Hegglin anomaly
d. Wiskott-Aldrich anomaly
c. May-Hegglin anomaly
- Which of the following is not a hallmark of ITP?
a. Petechiae
b. Thrombocytopenia
c. Large overactive platelets
d. Megakaryocyte hypoplasia
c. Large overactive platelets
- The specific antigen most commonly
responsible for the development of NAIT is:
a. Bak
b. HPA-1a
c. GPIb
d. Lewis antigen a
b. HPA-1a
- A 2-year-old child with an unexpected platelet count of 15,000/mL and a recent history of a viral infection most likely has:
a. HIT
b. NAIT
c. Acute ITP
d. Chronic ITP
c. Acute ITP
- Which drug causes a reduction in platelet
count by inhibiting megakaryocyte
maturation?
a. Gold salts
b. Abciximab
c. Anagrelide
d. Quinidine
c. Anagrelide
- When a drug acts as a hapten to induce
thrombocytopenia, an antibody forms against which of the following?
a. Typically unexposed, new platelet
antigens
b. The combination of the drug and
the platelet membrane protein to
which it is bound
c. The drug alone in the plasma, but the
immune complex then binds to the
platelet membrane
d. The drug alone, but only when it is
bound to the platelet membrane
b. The combination of the drug and
the platelet membrane protein to
which it is bound
- TAR refers to:
a. Abnormal platelet morphology in
which the radial striations of the
platelets are missing
b. Abnormal appearance of the iris of
the eye in which radial striations are
absent
c. Abnormal bone formation,
including hypoplasia of the forearms
d. Neurologic defects affecting the root
(radix) of the spinal nerves
c. Abnormal bone formation,
including hypoplasia of the forearms
- Neonatal autoimmune thrombocytopenia occurs when:
a. The mother lacks a platelet antigen
that the infant possesses, and she
builds antibodies to that antigen, which
cross the placenta
b. The infant develops an autoimmune
process such as ITP secondary to in
utero infection
c. The infant develops an autoimmune
disease such as lupus erythematosus
before birth
d. The mother has an autoimmune
antibody to her own platelets, which
crosses the placenta and reacts with
the infant’s platelets
d. The mother has an autoimmune
antibody to her own platelets, which
crosses the placenta and reacts with
the infant’s platelets
- HUS in children is associated with:
a. Diarrhea caused by Shigella
species
b. Meningitis caused by Haemophilus
species
c. Pneumonia caused by Mycoplasma
species d. Pneumonia caused by
respiratory viruses
a. Diarrhea caused by Shigella
species
- Treatment with an anticomplement agent such as eculizumab is first-line therapy for:
a. Hereditary TTP
b. Hemolytic uremic syndrome (HUS)
c. ITP
d. Atypical HUS
d. Atypical HUS
- Which of the following statements regarding thrombocytosis is not true?
a. Thrombocytosis can be associated
with hemorrhage and thrombosis
b. Affected patients have platelet counts
in excess of 450,000/mL
c. Thrombocytosis is self-correcting
d. Thrombocytosis can be congenital or
acquired
c. Thrombocytosis is self-correcting
- 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
b. 1 in 1000
- 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
a. Predisposition to thrombosis
secondary to a congenital or
acquired disorder
- What acquired thrombosis risk factor is
assessed in the hemostasis laboratory?
a. Smoking
b. Immobilization
c. Obesity
d. Lupus anticoagulant
d. Lupus anticoagulant
- 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
c. Adenocarcinoma
- 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
a. APC resistance (factor V Leiden
mutation)
- In most LAC profiles, what test is primary
(performed first) because it detects LAC with the least interference?
a. Low-phospholipid PTT
b. DRVVT
c. KCT
d. PT
b. DRVVT
- A patient with venous thrombosis is tested for protein S deficiency. The protein S activity, antigen, and free antigen are all 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%
a. Type I
- An elevated level of what fibrinolytic system assay is associ- ated with arterial thrombotic risk?
a. PAI-1
b. TPA
c. FactorVIIa
d. Factor XII
a. PAI-1
- 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 tenase
complex
c. It substitutes for plasminogen or
TPA in the forming clot
- What test may be used to confirm the
presence of LAC?
a. PT
b. Bethesda titer
c. Antinuclear antibody
d. DRVVT using high-phospholipid
reagent
d. DRVVT using high-phospholipid
reagent
- What molecular test may be used to confirm APC resis- tance?
a. Prothrombin G20210A
b. MTHFR 1298
c. MTHFR 677
d. Factor V Leiden
d. Factor V Leiden
- What therapeutic agent may occasionally cause DIC?
a. FactorVIII
b. Factor VIIa
c. Antithrombin concentrate
d. Activated prothrombin complex
concentrate
d. Activated prothrombin complex
concentrate
- Which is not a fibrinolysis control protein?
a. Thrombin-activatable fibrinolysis
inhibitor
b. Plasminogen activator inhibitor-1
c. a2-Antiplasmin
d. D-dimer
d. D-dimer
- 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
c. Rule out deep venous thrombosis
- What is the first laboratory assay necessary to detect heparin- induced thrombocytopenia?
a. Platelet count
b. H:PF4 immunoassay
c. Quick turnaround test
d. Serotonin release assay
a. Platelet count
- What is the PT/INR therapeutic range for
Coumadin therapy when a patient has a
mechanical heart valve?
a. 1 to 2
b. 2 to 3
c. 2.5 to 3.5
d. Coumadin is not indicated for patients
with mechanicalheart valves
c. 2.5 to 3.5
- Monitoring of a patient taking Coumadin
showed that her anticoagulation results
remained stable over a period of about 7
months. The frequency of her visits to the
laboratory began to decrease, so the period between testing averaged 6 weeks. This new testing interval is:
a. Acceptable for a patient with stable
anticoagulation results after 6
months
b. Unnecessary, because monitoring for
patients taking oral anticoagulants can
be discontinued entirely after 4 months
of stable test results
c. Too long even for a patient with
previously stable test results; 4 weeks isthe standard
d. Acceptable as long as the patient
performs self-monitor- ing daily using an
approved home testing instrument and
reports unacceptable results promptly to
her physician
a. Acceptable for a patient with stable
anticoagulation results after 6
months
- What is the greatest advantage of
point-of-care PT testing?
a. It permits self-dosing of Coumadin
b. It is inexpensive
c. It is convenient
d. It is precise
c. It is convenient
- You collect a citrated whole-blood specimen to monitor UFH therapy. What is the longest it may stand before the plasma must be separated from the cells?
a. 1 hour
b. 4 hours
c. 24 hours
d. Indefinitely
a. 1 hour
- What test is used to monitor high-dose UFH therapy during an interventional cardiology procedure?
a. PT
b. PTT
c. Bleeding time
d. ACT
d. ACT
- What test is used most often to monitor
UFH therapy in the central laboratory?
a. PT
b. PTT
c. ACT
d. Chromogenic anti-factor Xa heparin
assay
b. PTT
- What is an advantage of LMWH therapy over UFH therapy?
a. It is cheaper
b. It causes no bleeding
c. It has a predictable dose response
d. There is no risk of HIT
c. It has a predictable dose response
- What test is used most often to monitor
LMWH therapy in the central laboratory?
a. PT
b. PTT
c. ACT
d. Chromogenic anti-factor Xa
heparin assay
d. Chromogenic anti-factor Xa
heparin assay
- In what situation is an intravenous DTI used?
a. DVT
b. HIT
c. Any situation in which Coumadin
could be used
d. Uncomplicated AMI
b. HIT
- What laboratory test may be used to monitor intravenous DTI therapy when PTT results are unreliable?
a. PT
b. ECT
c. Reptilase clotting time
d. Chromogenic anti-factor Xa heparin
assay
b. ECT
- What is the reference method for detecting aspirin or clopidogrel resistance?
a. Platelet aggregometry
b. AspirinWorks
c. VerifyNow
d. PFA-100
a. Platelet aggregometry
- What is the name of the measurable platelet activation metabolite used in the AspirinWorks assay to monitor aspirin resistance?
a. 11-dehydrothromboxane B2
b. Arachidonic acid
c. Thromboxane A2
d. Cyclooxygenase
a. 11-dehydrothromboxane B2
- Which is an intravenous antiplatelet drug used during an interventional cardiology procedure?
a. Abciximab
b. Ticagrelor
c. Prasugrel
d. Clopidogre
a. Abciximab
- Which of the following is a DOAC?
a. Argatroban
b. Fondaparinux
c. Bivalirudin
d. Rivaroxaban
d. Rivaroxaban
- What happens if a coagulation specimen
collection tube is underfilled?
a. The specimen clots and is useless
b. The specimen is hemolyzed and is
useless
c. Clot-based test results are falsely
prolonged
d. Chromogenic test results are falsely
decreased
c. Clot-based test results are falsely
prolonged
- You perform whole-blood lumiaggregometry on a specimen from a patient who complains of easy bruising. Aggregation and secretion are diminished when the agonists thrombin, ADP,
arachidonic acid, and collagen are used. What is the most likely platelet abnormality?
a. Storage pool disorder
b. Aspirin-like syndrome
c. ADP receptor anomaly
d. Glanzmann thrombasthenia
d. Glanzmann thrombasthenia
- If you collect blood into a series of tubes,
when in the sequence should the hemostasis (blue stopper) tube be filled?
a. After a lavender-topped or
green-topped tube
b. First, or after a nonadditive tube
c. After a serum separator tube
d. Last
b. First, or after a nonadditive tube
- What is the effect of hemolysis on a
hemostasis specimen?
a. In vitro platelet and coagulation
activation
b. The specimen is icteric or lipemic
c. Hemolysis has no effect
d. The specimen is clotted
a. In vitro platelet and coagulation
activation
- Except for platelet aggregometry, most
coagulation testing must be performed on PPP, which is plasma with a platelet count less than:
a. 1000/mL
b. 10,000/mL
c. 100,000/mL
d. 1,000,000/mL
b. 10,000/mL
- You wish to obtain a 5-mL specimen of
whole-blood/ anticoagulant mixture. The
patient’s hematocrit is 65%. What volume of anticoagulant should you use?
a. 0.32 mL
b. 0.5 mL
c. 0.64 mL
d. 0.68 mL
a. 0.32 mL
- What is the reference assay for HIT?
a. Enzyme immunoassay
b. Serotonin release assay
c. Platelet lumiaggregometry
d. Washed platelet aggregation
b. Serotonin release assay
- What agonist is used in platelet aggregometry to detect VWD?
a. Arachidonic acid
b. Ristocetin
c. Collagen
d. ADP
b. Ristocetin
- Deficiency of which congenital single factor is likely when the PT result is prolonged and the PTT result is normal?
a. FactorV
b. Factor VII
c. FactorVIII
d. Prothrombin
b. Factor VII
- A prolonged PT, a low factor VII level, but a normal factor V level are characteristic of an acquired coagulopathy associated with which of the following?
a. Vitamin K deficiency
b. Thrombocytopenia
c. Liver disease
d. Hemophilia
a. Vitamin K deficiency
- What is the name given to the type of assay that uses a syn- thetic polypeptide substrate that releases a chromophore on digestion by its serine protease?
a. Clot-based assay
b. Molecular diagnostic assay
c. Fluorescence immunoassay
d. Chromogenic substrate assay
d. Chromogenic substrate assay
- The patient has deep vein thrombosis. The PTT is prolonged and is not corrected in an immediate mix of patient PPP with an equal part of PNP. What is the presumed condition?
a. Factor VIII inhibitor
b. Lupus anticoagulant
c. Factor VIII deficiency
d. Factor V Leiden mutation
b. Lupus anticoagulant
- What condition causes the most pronounced elevation in the result of the quantitative D-dimer assay?
a. Deep vein thrombosis
b. Fibrinogen deficiency
c. Paraproteinemia
d. DIC
d. DIC
- What component of the fibrinolytic process binds and neutralizes free plasmin?
a. TPA
b. PAI-1
c. Urokinase
d. A2-antiplasmin
d. A2-antiplasmin
- What type of high-throughput genomic
sequencing is likely to become a standard
clinical assay?
a. Human genotypic ontogeny
b. Whole-genome sequencing
c. Whole-exome sequencing
d. Gene-targeted sequencing
b. Whole-genome sequencing
- Which of the following is considered to be an advantage of the mechanical end-point detection methodology?
a. It is not affected by lipemia in the
test specimen
b. It has the ability to provide a graph of
clot formation
c. It can incorporate multiple
wavelengths into a single testing
sequence
d. It can measure proteins that do not
have fibrin formation as the end-point
a. It is not affected by lipemia in the
test specimen
- Which of the following includes the advances made in tech- nology in the coagulation lab?
a. Primary tube sampling
b. Random access testing
c. Reduced specimen and reagent
volumes
d. All of the above
d. All of the above
- What method of detection is used in both the TEG and ROTEM?
a. Photo-optical
b. Chromogenic end-point
c. Viscoelastic
d. Immunologic
c. Viscoelastic
- Which of the following is a feature of
semi-automated coagulation testing analyzers?
a. The temperature is maintained
externally by a heat block or water bath
b. Reagents and specimens usually
are added manually by the operator
c. Timers are automatically started as
soon as the analyzer adds reagents to
the test cuvette
d. The end-point must be detected by
the operator
b. Reagents and specimens usually
are added manually by the operator
- When a specimen has been flagged as being icteric by an automated coagulation analyzer, which method would be most susceptible to erroneous results because of the interfering substance?
a. Mechanical clot detection
b. Immunologic antigen-antibody
reaction detection
c. Photo-optical clot detection
d. Chromogenic end-point detection
c. Photo-optical clot detection
- Which of the following newer techniques can be used for the measurement of platelet function testing in patients with thrombocytopenia and in pediatrics?
a. PFA-100
b. Flow cytometry
c. Lumi-aggregation
d. PAP-8E
b. Flow cytometry
- All of the following are performance
characteristics to consider in the selection of a coagulation analyzer except:
a. Location of the manufacturer’s
home office
b. Instrument footprint
c. Ease of use for the operator
d. Variety of tests the instrument can
perform
a. Location of the manufacturer’s
home office
- Platelet function is measured by the PFA-100 using which of the following methods?
a. Detecting the change in blood flow
pressure along a small tube when a clot
impairs blood flow
b. Detecting the aggregation of latex
beads coated with platelet activators
c. Graphing the transmittance of light
through platelet-rich plasma over time
after addition of platelet activators
d. Detecting the time it takes for a
clot to form as blood flows through a
small aperture in a tube coated with
platelet activators
d. Detecting the time it takes for a
clot to form as blood flows through a
small aperture in a tube coated with
platelet activators
- A clinical setting where point-of-care testing is used in high volume is:
a. To monitor patients receiving oral
anticoagulant therapy
b. To monitor patients taking platelet
inhibitors such as Aspirin
c. To provide a baseline for all
subsequent patient test result
comparisons when the patient starts any
kind of anticoagulant therapy
d. To monitor obstetric patients at risk of
fetal loss
a. To monitor patients receiving oral
anticoagulant therapy
- Molecular testing can be used to diagnose patients with:
a. Thrombocytopenia
b. Factor V Leiden
c. Prothrombin 20210A
d. Both b and c
d. Both b and c
- The most common cause of anemia in
childhood is:
a. Vitamin B12 deficiency
b. Drug-related hemolysis
c. Iron deficiency
d. Folate deficiency
c. Iron deficiency
- The CBC results for children (aged 3 to 12 years) differ from those of adults chiefly in what respect?
a. NRBCs are present
b. Notable polychromasia is seen,
indicating increased reticulocytosis
c. Platelet count is lower
d. The percentage of lymphocytes is
higher
d. The percentage of lymphocytes is
higher
- Physiologic anemia of infancy results from:
a. Iron deficiency caused by a milk-only
diet during the early neonatal period
b. Increased oxygenation of blood
and decreased erythropoietin
c. Replacement of active marrow with fat
soon after birth
d. Hb F and its diminished oxygen
delivery to tissues
b. Increased oxygenation of blood
and decreased erythropoietin
- Morphologically, the hematogones in
newborns are:
a. Similar to those seen in megaloblastic
anemia
b. Easily confused with leukemic
blasts
c. Monocytoid in appearance
d. Similar to adult lymphocytes
b. Easily confused with leukemic
blasts
- Which of the following are the most common anemias in the elderly population?
a. Megaloblastic anemia and iron
deficiency anemia
b. Sideroblastic anemia and
megaloblastic anemia
c. Myelophthisic anemia and anemia of
chronic inflammation
d. Iron deficiency anemia and anemia
of chronic inflammation
d. Iron deficiency anemia and anemia
of chronic inflammation
- The physiologic anemia of pregnancy is a
result of:
a. A decrease of EPO response during
pregnancy
b. Inability of the pregnant woman to
absorb dietary iron
c. Increased hepcidin synthesis during
gestation
d. Increased plasma volume
proportionally greater than the
increase in RBC mass
d. Increased plasma volume
proportionally greater than the
increase in RBC mass
- Which of the following conditions is least likely in an elderly individual?
a. Acute lymphoblastic leukemia
b. Multiple myeloma
c. Myelodysplasia
d. Chronic lymphocytic leukemia
a. Acute lymphoblastic leukemia
- When iron deficiency is recognized in an
elderly individual, the cause is usually:
a. An iron-deficient diet
b. Gastrointestinal bleeding
c. Diminished absorption
d. Impaired incorporation of iron into
heme as a result of telomere loss
b. Gastrointestinal bleeding
- Which of the following is recommended as treatment for venous thromboembolism in pregnant women?
a. Coumadin
b. Unfractionated heparin (UFH)
c. Low-molecular-weight heparin
(LMWH)
d. Aspirin
c. Low-molecular-weight heparin
(LMWH)
- A pregnant woman was seen in the
emergency department with the following:
decreased platelet count, proteinuria,
fragmented RBCs, and increased liver enzymes. What is the most likely cause of these abnormalities?
a. HELLP syndrome
b. ITP
c. Antiphospholipid syndrome (APS)
d. DIC
a. HELLP syndrome
