Deck 26: Disorders of Plasma Clotting Factors

Question 1

Factor VIII:vWF is the carrier protein of the factor VIII complex and serves to concentrate __________ present in small amounts to the site of the injury.

A) VIII:vWF
B) VIII:Ag
C) VIII:C
D) All of the above
E) None of the above

Answer 1

VIII:C

Question 2

The bleeding time in von Willebrand's disease (vWD) will correct with infusion of _________.

A) Normal platelets
B) Normal plasma
C) Plasma from person with vWD
D) All of the above
E) None of the above

Answer 2

Normal plasma

Question 3

Clinical histories of patients with hemophilia A may indicate all of the following symptoms except:

A) Hemarthroses
B) Postoperative bleeding
C) Hematuria
D) Hypertension
E) None of the above

Answer 3

Hypertension

Question 4

All of the following are bleeding manifestations of vWD except:

A) Epistaxis
B) Easy bruising
C) Hemarthrosis
D) Mucous membrane bleeds
E) None of the above

Question 5

Which test(s) (is) are performed in screening for vWD?

A) vWF activity
B) APTT
C) Bleeding time
D) FVIII:C level
E) All of the above

Question 6

All of the following are laboratory findings consistent with hemophilia A except:

A) Prolonged APTT
B) Prolonged bleeding time
C) Normal PT
D) Normal vWF:Ag
E) Normal platelet count

Question 7

A patient with hemophilia A contains 4% VIII:C activity. This hemophilia is classified as __________.

A) Mild
B) Moderate
C) Severe
D) Variable
E) None of the above

Question 8

Which factor is impaired in hemophilia A?

A) VIII:Ag
B) VIII:vWF
C) VIII:C
D) All of the above
E) None of the above

Question 9

One of the central causes of vWD is the inability of the patient's __________ to adhere to the subendothelial surfaces following injury to the blood vessel.

A) Granulocytes
B) Platelets
C) Lymphocytes
D) Erythrocytes
E) None of the above

Question 10

In hemophilia A patients, factor VIII:C should be maintained at a level of at least __________ percent of normal activity.

A) 50
B) 30
C) 10
D) 40
E) None of the above

Question 11

The site of factor VIII:C synthesis may originate in all of the following except:

A) Liver
B) Kidney
C) Endothelial cells
D) Megakaryocytes
E) None of the above

Question 12

What statement is true regarding factor VIII?

A) Factor VIII is absent in absorbed plasma.
B) Factor VIII is present in serum.
C) Factor VIII is vitamin K dependent.
D) Factor VIII is extremely thermolabile.
E) All of the above

Question 13

How is the level of factor VIII:C measured in the laboratory?

A) A two-stage activated partial thromboplastin time (APTT)-based factor assay
B) A two-stage prothrombin time (PT)-based factor assay
C) A one-stage APTT-based factor assay
D) A one-stage PT-based factor assay
E) None of the above

Question 14

Factor VIII:C is the __________ protein subunit of the factor VIII complex and represents the __________ or clotting activity of the complex.

A) Smaller/procoagulant
B) Major/procoagulant
C) Major/von Willebrand factor activity
D) Smaller/von Willebrand activity
E) None of the above

Question 15

Which is (are) an effective treatment(s) for vWD?

A) Cryoprecipitate
B) Concentrates of vWF
C) Red blood cells
D) A and B
E) A and C

Question 16

All of the following are characteristics of inhibitors to factor VIII:C seen in hemophilia A except:

A) Neutralize factor VIII:C at 37°C
B) Temperature dependent
C) IgM in nature
D) IgG in nature
E) None of the above

Question 17

vWD is an autosomal dominant disorder characterized by decreased or absent __________ and a decrease in factor __________ secondary to the primary defect in vWF.

A) vWF/IX
B) VIII:C/vWF
C) vWF/VIII:C
D) IX/VIII:C
E) None of the above

Question 18

What is the most widely accepted treatment used in hemophilia A?

A) Cryoprecipitate
B) Lyophilized factor VIII concentrates
C) Immune globulin
D) Lyophilized factor IX
E) All of the above

Question 19

Hemophilia A is a __________ disorder that affects approximately one male per 10,000 people in the world population.

A) Autosomal dominant
B) Sex-linked recessive
C) Autosomal recessive
D) Sex-linked dominant
E) None of the above

Question 20

How is the presence of VIII:vWF demonstrated in the laboratory?

A) One-stage APTT
B) Platelet response to aggregation by ristocetin
C) One-stage PT
D) Reptilase test
E) None of the above

Question 21

How does hemophilia B differ from hemophilia A?

A) Inheritance
B) Bleeding sites
C) Bleeding time
D) Inhibitor production
E) None of the above

Question 22

What is the range of fibrinogen in patients with hypofibrinogenemia?

A) 20-100 mg/dL
B) 200-400 mg/dL
C) 50-100 mg/dL
D) 100-350 mg/dL
E) None of the above

Question 23

What is (are) appropriate treatments in patients with hemophilia B?

A) Prothrombin-complex concentrates
B) Factor IX concentrates
C) Fresh frozen plasma
D) All of the above
E) None of the above

Question 24

A factor X deficiency may result in all of the following except:

A) Epistaxis
B) Gastrointestinal bleeding
C) Easy bruising
D) Hematomas
E) Hemarthroses

Question 25

What is the normal range of fibrinogen in plasma?

A) 50-300 mg/dL
B) 100-350 mg/dL
C) 200-400 mg/dL
D) 100-200 mg/dL
E) None of the above

Question 26

What do laboratory results demonstrate in factor V deficiencies?

A) Prolonged PT, normal APTT
B) Prolonged PT and APTT
C) Normal PT
D) Normal APTT
E) None of the above

Question 27

What is the treatment of choice in the acquired dysprothrombinemias?

A) Immunosuppressive drugs
B) Whole blood
C) Prothrombin complex concentrates
D) Hormonal therapy
E) None of the above

Question 28

All of the following statements are true regarding factor IX except:

A) Factor IX is a vitamin K-dependent factor.
B) Factor IX is synthesized in the liver.
C) Factor IX is increased in hemophilia B.
D) Factor IX is present in serum but not in absorbed plasma.
E) Factor IX is decreased in liver disease.

Question 29

A normal reptilase time and a prolonged thrombin time suggest the presence of __________.

A) Calcium
B) Prothrombin
C) Heparin
D) Fibrinogen abnormality
E) None of the above

Question 30

Prothrombin complex concentrates consist of which plasma factors?

A) II, VII, XI, XII
B) I, II, V, IX, X
C) I, IV, V, VII, XII
D) II, VII, IX, X
E) None of the above

Question 31

Which laboratory test is abnormal in afibrinogenemia?

A) TT
B) PT
C) APTT
D) Reptilase time
E) All of the above

Question 32

Which laboratory test is prolonged in a factor XII deficiency?

A) TT
B) PT
C) APTT
D) All of the above
E) None of the above

Question 33

__________ acts as the stabilizer of the fibrin gel.

A) Factor X
B) Factor XIII
C) Factor I
D) Factor VI
E) Factor VII

Question 34

Acquired deficiencies of factor VII are associated with:

A) Liver disease
B) Coumadin therapy
C) Vitamin K deficiency
D) All of the above
E) None of the above

Question 35

All of the following are manifestations of afibrinogenemia except:

A) Epistaxis
B) Umbilical cord blood bleeding
C) Gingival bleeding
D) Deep hematomas
E) Easy bruising

Question 36

In the laboratory assessment of hemophilia B, the one-stage APTT factor assay for factor IX is __________.

A) Increased
B) Normal
C) Decreased
D) Variable
E) None of the above

Question 37

Which conditions or factors lead to a decrease in factor II?

A) Liver dysfunction
B) Broad-spectrum antibiotic use
C) Coumarin therapy
D) Abnormal absorption of vitamin K in intestinal tract
E) All of the above

Question 38

Which laboratory tests are normal in prekallikrein deficiency?

A) PT
B) TT
C) Bleeding time
D) All of the above
E) None of the above

Question 39

Which rare inherited disorder results in a failure to synthesize adequate amounts of circulating fibrinogen?

A) Afibrinogenemia
B) Dysfibrinogenemia
C) Wiskott-Aldrich syndrome
D) von Willebrand's disease
E) None of the above

Question 40

The reptilase time is a test that is used to differentiate the presence of __________ from a fibrinogen abnormality.

A) Heparin
B) Coumarin
C) Warfarin
D) Lupus anticoagulant
E) All of the above

Question 41

In variant vWD, identification is essential for proper treatment. This can be accomplished by:

A) Ristocetin-induced platelet aggregation studies
B) Multimeric analysis
C) Factor VIII:C, factor VIII:R Co, vWF:Ag
D) A and B
E) All of the above

Question 42

Which factor of the contact system, if deficient, may lead to a bleeding condition?

A) Fitzgerald factor (high-molecular-weight kininogen)
B) Fletcher factor (prekallikrein)
C) Hageman factor (factor XII)
D) Plasma thromboplastin antecedent (factor XI)
E) None of the above

Question 43

The most common form of vWD is:

A) Type 2B
B) Type 1
C) Type 3
D) Pseudo-platelet type
E) Type A

Question 44

All of the following are true regarding circulating anticoagulants except:

A) They are usually immunoglobulins.
B) They are exogenously produced substances.
C) They are inhibitors of the coagulation system.
D) They are endogenously produced substances.
E) None of the above

Question 45

Anti-factor VIII antibodies (inhibitors) may arise:

A) Spontaneously
B) In the elderly
C) Due to factor replacement therapy
D) None of the above
E) All of the above

Question 46

An example of a specific inhibitor is __________.

A) Lupus anticoagulants
B) Antibodies to factor VIII:C
C) Anticardiolipin antibodies
D) All of the above
E) None of the above

Question 47

All of the following are characteristics of lupus anticoagulants except:

A) They are spontaneously occurring inhibitors that are immunoglobulins.
B) They directly react against anionic phospholipids in vitro.
C) They enhance the formation of the prothrombinase complex.
D) They prolong the phospholipid-dependent tests PT, APTT, and Russell viper venom time (RVVT).
E) They are associated with thrombosis problems.

Question 48

The persistence of activated factor V in the circulation is caused by:

A) Antithrombin III
B) Antiphospholipid antibodies
C) Activated protein C resistance
D) Dysfibrinogenemia
E) Protein C