310 exam 1 book Qs

What intimal cell synthesizes and stores von Willebrand factor (VWF)?

Endothelial cell

What subendothelial structural protein triggers coagulation through activation of factor VII?

Tissue factor

What coagulation plasma protein should be assayed when platelets fail to aggregate properly?

Fibrinogen

What is the primary role of vitamin K for the prothrombin group factors?

Carboxylates the factors to allow calcium binding

What is the source of prothrombin fragment F1.2?

Thrombin proteolysis of fibrinogen

What serine protease forms a complex with factor VIIIa, and what is the substrate of this complex?

Factor IXa, factor X

What protein secreted by endothelial cells activates fibrinolysis?

TPA

What two regulatory proteins form a complex that digests activated factors V and VIII?

APC and protein S

What are the primary roles of VWF?

Mediate platelet adhesion and serve as a carrier molecule for factor VIII

Most coagulation factors are synthesized in:

The liver

The events involved in secondary hemostasis:

Lead to the formation of a stable fibrin clot

Which of the following coagulation factors is activated by thrombin and mediates the stabilization of the fibrin clot?

Factor XIII

Which of the following endogenous plasma inhibitors is (are) important for the control of excessive thrombin generation?

AT, TFPI

The clinical presentation of platelet-related bleeding may include all of the following except:

Bleeding into the joints (hemarthroses)

A defect in GP IIb/IIIa causes:

Glanzmann thrombasthenia

Patients with Bernard-Soulier syndrome have which of the following laboratory test findings?

Abnormal platelet response to ristocetin

Which of the following is the most common of the hereditary platelet function defects?

Storage pool defects

A reduction in thrombin generation in patients with Scott syndrome results from:

Altered expression of phospholipids on the platelet membrane

The impaired platelet function in myeloproliferative neoplasms results from:

Decreased numbers of α granules and dense granules

The platelet defect associated with increased paraproteins is:

Impaired membrane activation, owing to protein coating

In uremia, platelet function is impaired by higher than normal levels of:

NO

Thrombocytopenia associated with the use of cardiopulmonary bypass is not caused by:

Anti-GP IIb/IIIa antibodies

Aspirin ingestion blocks the synthesis of:

Thromboxane A₂

A mechanism of antiplatelet drugs targeting GP IIb/IIIa function is:

Direct binding to GP IIb/IIIa

Which is a congenital qualitative platelet disorder?

Ehlers-Danlos syndrome

The autosomal dominant disorder associated with decreased platelet production is:

May-Hegglin anomaly

Which of the following is not a hallmark of ITP?

Large overactive platelets

The specific antigen most commonly responsible for the development of NAIT is:

HPA-1a

A 2-year-old child with an unexpected platelet count of 15,000/μL and a recent history of a viral infection most likely has:

Acute ITP

Which drug causes a reduction in platelet count by inhibiting megakaryocyte maturation?

Anagrelide

A defect in primary hemostasis (platelet response to an injury) often results in:

Mucosal bleeding

When a drug acts as a hapten to induce thrombocytopenia, an antibody forms against which of the following?

The combination of the drug and the platelet membrane protein to which it is bound

TAR refers to:

Abnormal bone formation, including hypoplasia of the forearms

Neonatal autoimmune thrombocytopenia occurs when:

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:

Diarrhea caused by Shigella species

Treatment with an anticomplement agent such as eculizumab is first-line therapy for:

Atypical HUS

Which of the following statements regarding thrombocytosis is not true?

Thrombocytosis is self-correcting

Which of the following includes the advances made in technology in the coagulation lab?

All of the above

Which of the following is considered to be an advantage of the mechanical end-point detection methodology?

It is not affected by lipemia in the test specimen

What method of detection is used in both the TEG and ROTEM?

Viscoelastic

Which of the following is a feature of semiautomated coagulation testing analyzers?

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?

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?

Flow cytometry

All of the following are performance characteristics to consider in the selection of a coagulation analyzer except:

Location of the manufacturer’s home office

Platelet function is measured by the PFA-100 using which of the following methods?

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:

To monitor patients receiving oral anticoagulant therapy

Molecular testing can be used to diagnose patients with:

Both Factor V Leiden and Prothrombin 20210A

What happens if a coagulation specimen collection tube is underfilled?

Clot-based test results are falsely prolonged

If you collect blood into a series of tubes, when in the sequence should the hemostasis (blue stopper) tube be filled?

First, or after a nonadditive tube

What is the effect of hemolysis on a hemostasis specimen?

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:

10,000/μL

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?

0.32 mL

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?

Glanzmann thrombasthenia

What is the reference assay for HIT?

Serotonin release assay

What agonist is used in platelet aggregometry to detect VWD?

Ristocetin

Deficiency of which congenital single factor is likely when the PT result is prolonged and the PTT result is normal?

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?

Vitamin K deficiency

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?

Lupus anticoagulant

What condition causes the most pronounced elevation in the result of the quantitative D-dimer assay?

DIC

What is the name given to the type of assay that uses a synthetic polypeptide substrate that releases a chromophore on digestion by its serine protease?

Chromogenic substrate assay

What component of the fibrinolytic process binds and neutralizes free plasmin?

α₂-antiplasmin

What type of high-throughput genomic sequencing is likely to become a standard clinical assay?

Whole-genome sequencing

Which of the following receptors is/are involved in PLT adhesion to subendothelium?

GPIb/IX/V & GPVI

Which of the following receptors is/are involved in PLT aggregation?

GPIIb/IIIa

Deletion or deficiency of GPIb/IX/V may disrupt the effect of which agonist?

ristocetin

Which of the following is true regarding BT (bleeding time test)?

It is a screening test to evaluate 1˚ hemostasis but is prone to variations

A young male patient consumed one tablet of aspirin and two capsules of indomethacin this morning (8:00) to alleviate some pains he has been having for a while. His BT test is scheduled for 10:00. How would you deal with this situation?

The test must be postponed for one week, so the drugs are completely cleared from circulation