Deck 25: Disorders of Primary Hemostasis: Quantitative and Qualitative Platelet Disorders and Vascular Disorders

Question 1

von Willebrand's disease (vWD) and Bernard-Soulier syndrome represent disorders of platelet __________.

A) Aggregation
B) Adhesion
C) Secretion
D) Response
E) None of the above

Answer 1

Adhesion

Question 2

All of the following factors are decreased in vWD except:

A) VIII
B) vWF:Ag
C) IX
D) Ristocetin cofactor
E) von Willebrand factor (vWF)

Answer 2

IX

Question 3

The __________ is used to detect quantitative platelet disorders.

A) Bleeding time
B) Platelet count
C) Thrombin time
D) Fibrinogen
E) None of the above

Answer 3

Platelet count

Question 4

vWD is characterized by:

A) Mucocutaneous bleeding
B) Reduced levels of factor VIII
C) Prolonged bleeding time
D) All of the above
E) None of the above

Question 5

The congenital disorders of platelet function include defects in all of the following except:

A) Platelet adhesion
B) Platelet maturation
C) Platelet aggregation
D) Platelet storage or secretion
E) Platelet-coagulant protein interaction

Question 6

How is May-Hegglin anomaly distinguished from Bernard-Soulier syndrome?

A) Giant platelets on peripheral blood smear
B) Moderate thrombocytopenia
C) Normal platelet membrane glycoprotein and platelet function
D) All of the above
E) None of the above

Question 7

The laboratory tests used in the diagnosis of vWD include all of the following except:

A) Bleeding time
B) Activated partial thromboplastin time (APTT)
C) Prothrombin time (PT)
D) Factor VIII levels
E) Platelet aggregation in response to ristocetin

Question 8

Treatment of patients with Glanzmann's thrombasthenia who present with severe bleeding episodes is __________.

A) Blood transfusions
B) Platelet transfusions
C) Gamma globulin
D) Bone marrow transplants
E) None of the above

Question 9

The etiology of Glanzmann's thrombasthenia results from the inability of __________ to bind to platelet surface membranes, which would normally result in aggregation.

A) Fibrinogen
B) Plasmin
C) Thrombin
D) Calcium
E) None of the above

Question 10

__________ is a rare autosomal recessive disorder of platelet function associated with an abnormality of membrane glycoproteins IIb and IIIa, causing decreased platelet aggregation.

A) Bernard-Soulier syndrome
B) Glanzmann's thrombasthenia
C) von Willebrand's disease
D) Congenital afibrinogenemia
E) None of the above

Question 11

A qualitative disorder of platelet secretion is __________.

A) Storage pool deficiency
B) Aspirin-like defects
C) May-Hegglin anomaly
D) A and B
E) All of the above

Question 12

The prolonged bleeding time and low factor VIII levels in vWD are corrected after __________ infusion.

A) Gamma globulin
B) Plasma
C) Platelet
D) Blood
E) None of the above

Question 13

All of the following are established criteria for the diagnosis of Bernard-Soulier syndrome except:

A) An autosomal trait with clinical manifestations expressed in homozygotes
B) Platelet agglutination in response to vWF plus ristocetin
C) Moderate thrombocytopenia with adequate number of marrow megakaryocytes
D) Presence of giant platelets present on peripheral blood smear
E) Normal platelet aggregation in response to ADP, collagen, and epinephrine

Question 14

Glanzmann's thrombasthenia and congenital afibrinogenemia are qualitative disorders of platelet __________.

A) Aggregation
B) Adhesion
C) Secretion
D) Response
E) None of the above

Question 15

Which laboratory findings differentiate Bernard-Soulier syndrome from Glanzmann's thrombasthenia?

A) Decreased platelet count
B) Prolonged bleeding time
C) Abnormal platelet aggregation in response to thrombin
D) All of the above
E) None of the above

Question 16

Endothelial cells and __________ are known to synthesize vWF.

A) Neutrophils
B) Monocytes
C) Megakaryocytes
D) Erythrocytes
E) None of the above

Question 17

Criteria for diagnosing Glanzmann's thrombasthenia include:

A) An autosomal recessive trait with clinical manifestations expressed in homozygotes only
B) Prolonged bleeding time
C) Normal platelet count
D) Absence of platelet aggregation to ADP (thrombin, collagen, and epinephrine)
E) All of the above

Question 18

Laboratory findings that are hallmarks of Glanzmann's thrombasthenia include all but which of the following?

A) Normal platelet count
B) Prolonged bleeding time
C) Presence of clot retraction
D) Absence of aggregation to ADP
E) Absence of aggregation to collagen

Question 19

Which qualitative congenital platelet disorder is characterized by a prolonged bleeding time; unusually large platelets; and decrease in platelet surface glycoprotein Ib, glycoprotein V, and glycoprotein IX resulting in decreased platelet adhesion?

A) Storage pool deficiency
B) Glanzmann's thrombasthenia
C) von Willebrand's disease
D) Bernard-Soulier syndrome
E) None of the above

Question 20

The prolonged bleeding time and abnormal platelet adhesion seen in vWD is due to the lack of __________.

A) Glycoprotein Ib
B) vWD
C) Glycoprotein IIb
D) Protein 4.1
E) None of the above

Question 21

All of the following are clinical features of TTP except:

A) Poikilocytosis
B) Reticulocytosis
C) Abnormal PT
D) Nucleated red blood cells (NRBCs)
E) Decreased haptoglobin

Question 22

Decreased platelet production may be associated with congenital or acquired disorders that affect the bone marrow, resulting in __________.

A) Megakaryocytic hypoplasia
B) Megakaryocytic hyperplasia
C) Myeloblast hypoplasia
D) Erythroid hypoplasia
E) None of the above

Question 23

Individuals with chronic liver disease are often associated with a significant hemorrhagic diathesis. Abnormal platelet function tests in these patients include all of the following except:

A) Reduced platelet adhesion
B) Abnormal platelet aggregation with ristocetin
C) Abnormal PF3 availability
D) Abnormal platelet aggregation to thrombin
E) None of the above

Question 24

The malignant paraproteins result in:

A) Coagulation abnormalities
B) Acquired circulating anticoagulants
C) Platelet dysfunction
D) All of the above
E) None of the above

Question 25

The spleen normally pools approximately __________ of all circulating platelets.

A) 1/8
B) 1/2
C) 1/3
D) 1/4
E) None of the above

Question 26

Quantitative congenital disorders that produce hypoplasia of megakaryocytes include all of the following except:

A) Fanconi's anemia
B) Thalassemia
C) May-Hegglin anomaly
D) TAR syndrome
E) None of the above

Question 27

Which laboratory findings differentiate vWD from Glanzmann's thrombasthenia?

A) Prolonged bleeding time
B) Normal aggregation to ADP and thrombin
C) Normal platelet count
D) All of the above
E) None of the above

Question 28

Which nonimmunologic quantitative platelet disorder is characterized by thrombocytopenia, microangiopathic hemolytic anemia, fluctuating neurologic abnormalities, renal disease, and hyaline microthrombi?

A) Hemolytic uremic syndrome
B) Thrombotic thrombocytopenic purpura (TTP)
C) Respiratory distress syndrome
D) Idiopathic thrombocytopenic purpura (ITP)
E) None of the above

Question 29

All of the following are possible mechanisms for the pathogenesis in TTP except:

A) TTP plasma is deficient in a platelet-aggregating factor inhibitor
B) Large vWF multimers promote platelet agglutination.
C) Endothelial cell damage via a plasma factor results in platelet adhesion.
D) Inhibition of cyclo-oxygenase (aspirin-like)
E) Deficiency of prostacyclin (PGI₂) synthesis and release leading to platelet aggregation and thrombosis

Question 30

All of the following disorders have been associated with storage pool deficiencies except:

A) Chédiak-Higashi syndrome
B) Hermansky-Pudlak syndrome
C) Pelger-Huët anomaly
D) Wiskott-Aldrich syndrome
E) Thrombocytopenia with absent radius (TAR) syndrome

Question 31

Prolonged __________ is associated with the use of aspirin, which is generally dose dependent.

A) Thrombin time
B) Platelet Function Analyzer (PFA)
C) Prothrombin time
D) APTT
E) None of the above

Question 32

Ineffective thrombopoiesis is defined as:

A) The state in which the number of megakaryocytes in the bone marrow is normal to increased, but maturation and release is abnormal
B) The state in which the number of megakaryocytes in the bone marrow is decreased
C) The state in which the number of megakaryocytes in the bone marrow is normal to decreased, but maturation and release is normal
D) The state in which the number of thrombocytes in the bone marrow is normal to increased, but maturation and release is abnormal
E) None of the above

Question 33

Uremia is a __________ platelet disorder.

A) Congenital
B) Qualitative
C) Quantitative
D) Nosocomial
E) None of the above

Question 34

__________ is a common clinical manifestation of the various paraproteinemias.

A) Thromboembolism
B) Bleeding
C) Thyroid dysfunction
D) Disseminating intravascular coagulation (DIC)
E) None of the above

Question 35

Laboratory findings in the storage pool deficiencies include all of the following except:

A) Absence of secondary aggregation in response to ADP and epinephrine
B) Normal prothrombin and partial thromboplastin times
C) Impaired platelet factor III availability
D) Normal primary aggregation
E) Decreased platelet retention to glass beads

Question 36

The average platelet count ranges from __________ of whole blood.

A) 50-100  10⁹/µL
B) 350-600  10⁹/µL
C) 150-400  10⁹/µL
D) 50-300  10⁹/µL
E) None of the above

Question 37

Thrombocytosis is classified as:

A) Platelet count <400  10³/µL
B) Platelet count >400  10³/µL
C) Platelet count 100-350  10³/µL
D) Platelet count is >50  10³/µL
E) None of the above

Question 38

The platelet count is a routine screening test used to detect __________ changes such as thrombocytosis and thrombocytopenia.

A) Qualitative
B) Quantitative
C) Phagocytic
D) Glomerular
E) None of the above

Question 39

What is the treatment of choice to convert the hemostatic defect in uremia?

A) Steroids
B) Hemodialysis
C) Blood transfusion
D) Immunosuppressant drugs
E) None of the above

Question 40

In patients with alcoholic cirrhosis, thrombocytopenia and platelet abnormalities may result from the direct toxic effect of alcohol on bone marrow __________, leading to an ineffective thrombopoiesis.

A) Lymphoblasts
B) Myelocytes
C) Megakaryocytes
D) Myeloblasts
E) Erythroid precursors

Question 41

The treatment of choice for chronic ITP after failure to maintain an adequate response to steroid therapy is _________.

A) Gamma globulin
B) Plasma exchange
C) Splenectomy
D) Immunosuppressive drugs
E) None of the above

Question 42

Spontaneous serious complications such as epistaxis, gingival bleeding, menorrhagia, and gastrointestinal bleeding usually are not present until the platelet count is:

A) 400-500  10⁹/L
B) 100-400  10⁹/L
C) 50-100  10⁹/L
D) <20  10⁹/L
E) None of the above

Question 43

__________ is a frequently observed complication of heparin therapy.

A) Thrombocytopenia
B) Thrombocytosis
C) Leukocytes
D) Leukopenia
E) None of the above

Question 44

Typical blood smear morphology in ITP includes:

A) Schistocytes
B) Nucleated red blood cells
C) Increased numbers of normal eosinophils
D) Large granular platelets
E) Platelet satellitism

Question 45

A patient whose serum contains or is known to have contained the antibody to the P1^A¹ antigen should receive __________ in all subsequent transfusions.

A) P1^A2-negative blood
B) P1^A2-positive blood
C) P1^A1-positive blood
D) P1^A1-negative blood
E) None of the above

Question 46

Heparin induced thrombocytopenia is caused by:

A) Destruction of marrow megakaryocyte by heparin
B) Splenic sequestration of heparin antibody complex coated platelets
C) Heparin-antibody complex mediated platelet activation causing platelet consumption
D) Inhibition of platelet release reactions by heparin
E) Suppression of marrow megakaryocyte platelet production by heparin

Question 47

Thrombocytosis may result from which of the following?

A) Increased platelet production
B) Proliferation of megakaryocytes
C) Reactive to transient stimuli to the bone marrow
D) Chronic marrow stimulation by malignancy or inflammation
E) All of the above

Question 48

The most common clinical and diagnostic finding of vascular disorders is _____________.

A) Epistaxis
B) Purpura
C) Mucocutaneous bleeding
D) Gastrointestinal bleeding
E) None of the above

Question 49

In a woman who presents in her first trimester of her first pregnancy with a platelet count of 80  10⁹/L, you must consider which of the following diagnoses?

A) Gestational thrombocytopenia
B) ITP
C) Eclampsia [HELLP syndrome (hemolytic anemias, elevated liver enzymes, and low platelet count)]
D) Folic acid deficiency
E) All of the above

Question 50

The most important therapeutic intervention for suspected heparin-induced thrombocytopenia is:

A) Warfarin
B) Lepthirudin (recombinant form of hirudin)
C) Dextran
D) Aspirin
E) Discontinuation of heparin

Question 51

The antibody present in the patient's serum in posttransfusion purpura is directed against the platelet antigen __________.

A) P1^A2
B) P1^A1
C) Bg^a
D) Cs^a
E) None of the above

Question 52

A deficiency of ___________________ results in gray platelet syndrome:

A) GPV
B) GPIIb/IIIa
C) Granules
D) High-molecular-weight vWF
E) Cyclo-oxygenase deficiency

Question 53

The treatment of choice for patients diagnosed with TTP is __________.

A) Heparin
B) Plasma exchange
C) Splenectomy
D) Corticosteroids
E) None of the above

Question 54

The P1^A1 antigen is found in __________ of the normal population.

A) 97%
B) 3%
C) 55%
D) 61%
E) 35%

Question 55

Platelet transfusion administration for bleeding episodes in Glanzmann's thrombasthenia is associated with:

A) Development of antibodies to GPIIb/IIIa
B) Development of paradoxical thrombocytopenia and worsening bleeding
C) Development of anti D antibodies
D) Arterial and venous thrombosis
E) All of the above

Question 56

Which strongly immunogenic antigen is associated with isoimmune neonatal thrombocytopenia?

A) Cs^a
B) P1^A1
C) P1^A2
D) P1^A3
E) None of the above

Question 57

Which purpose would a splenectomy serve in treatment of acute ITP?

A) Enhance cellular sequestration
B) Remove circulating immunoglobulin from circulation
C) Remove the primary site of platelet destruction and antibody production
D) Upregulate the reticuloendothelial system
E) None of the above

Question 58

__________ is an immune disorder that presents with thrombocytopenia one week after transfusion of blood or blood products containing platelets.

A) Respiratory distress syndrome
B) ITP
C) Isoimmune neonatal thrombocytopenia
D) Post-transfusion purpura
E) None of the above

Question 59

What are the clinical manifestations of isoimmune-neonatal thrombocytopenia?

A) Scattered petechiae
B) Platelet count below 30  10⁹/L
C) Purpuric hemorrhages
D) All of the above
E) None of the above

Question 60

__________ results from immunization of the mother by fetal platelet antigen and placental transfer of maternal antibody.

A) Isoimmune neonatal thrombocytopenia
B) Uremia
C) Posttransfusion purpura
D) Respiratory distress syndrome
E) None of the above

Question 61

Laboratory findings in TTP include all of the following except:

A) Reticulocytosis
B) Thrombocytosis
C) Elevated LDH
D) Schistocytosis
E) Decreased haptoglobin

Question 62

All of the following are characteristic of hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) except:

A) Telangiectatic lesions occur on mucus membranes.
B) Iron deficiency anemia is usually present.
C) Abnormal platelet aggregation in response to thrombin is present.
D) Epistaxis is common.
E) An autosomal inheritance pattern is present.