Deck 34: Disorders of Secondary Hemostasis

Question 1

Which congenital deficiency(ies) is(are) suspected with a normal platelet count, an abnormal PT and APTT, and normal PFA-100 and thrombin time?

A) Factor VII
B) Factors X, V, II (prothrombin)
C) Factor VIII
D) Fibrinogen

Answer 1

Factors X, V, II (prothrombin)

Question 2

F-VIII deficiency and F-IX deficiency are classified as what category of disorder?

A) Autosomal dominant
B) X-linked recessive
C) Autosomal recessive
D) X-linked dominant

Answer 2

X-linked recessive

Question 3

Deficiency of coagulation proteins is defined as a decrease in:

A) The concentration of the coagulation proteins
B) The concentration of the coagulation proteins and a subsequent decrease in the functionality of those proteins
C) The concentration of the coagulation proteins or impaired functionality of those proteins
D) Platelets that causes a decreased functionality of the coagulation proteins

Answer 3

The concentration of the coagulation proteins or impaired functionality of those proteins

Question 4

Which of the following clinical symptoms correlates with a severe form of hemophilia A or B?

A) Bleeding at circumcision with a factor level of 1-5 U/dL
B) Excessive bleeding after surgery or trauma with a factor level of 6-30 U/dL
C) Frequent spontaneous hemarthroses
D) Infrequent spontaneous joint and tissue bleeds

Question 5

What is the inheritance pattern of hemophilia A?

A) Autosomal dominant
B) Autosomal recessive
C) Sex-linked
D) None of these

Question 6

One of the most common hemostatic abnormalities found in "sick" infants is:

A) DIC
B) Factor XIII deficiency
C) Hemophilia
D) Vitamin K deficiency

Question 7

What term describes hereditary or acquired disorders that relate to the absence of a coagulation protein or to a protein that is present in the plasma but is functionally defective?

A) Circulating anticoagulant
B) Lupus anticoagulant
C) Deficiency
D) Dysfunctional

Question 8

George Jones is admitted to the hospital with abdominal pain. Upon physical examination, the attending physician notices a yellow ring around his green eyes. George has a significant swelling in his abdomen and has been suffering from swollen joints for the last month. The physician runs a battery of labs. The results follow: Based on this information, from what is George most likely suffering?

A) Liver disease
B) Vitamin K deficiency
C) Disseminated intravascular coagulation
D) Massive cerebral hemorrhage

Question 9

A patient might be suffering from a coagulopathy. Which of the following physical manifestations would suggest a primary hemostatic pathway problem?

A) Hematomas
B) Petechiae
C) Joint and muscle bleeding
D) Ecchymoses

Question 10

Interpret the following results: PT: 11.8 sec (RR: 11.2-13.8 sec)
INR: 1.07
APTT: 57 sec (RR: 23-32 sec)
Closure time: increased
Ristocetin aggregation: decreased aggregation
Based on this information, what is the most likely disorder?

A) Hemophilia A
B) Bernard-Soulier syndrome
C) DIC
D) von Willebrand's disease

Question 11

What is the most probable diagnosis?

A) von Willebrand's disease
B) DIC
C) Hemophilia possibly
D) Lupus anticoagulant

Question 12

Screening tests for the evaluation of VWD include the platelet count, APTT, PT, bleeding time, and/or PFA-100. Which of the following results would be evident in most cases of VWD?

A) Low platelet count
B) Decreased ristocetin platelet aggregation
C) Normal ristocetin platelet aggregation
D) Normal Ag assay

Question 13

A 5-year-old boy has his blood drawn for platelet aggregation studies. Ristocetin aggregation (RIPA) comes back abnormal with all other agonists displaying normal aggregation. VWF antigen is within normal limits. What is the most likely reason for this discrepancy?

A) The VWF antigen test was performed incorrectly and should be repeated.
B) The patient might be suffering from a qualitative platelet defect disorder.
C) The RIPA exam was performed incorrectly and should be repeated.
D) Multimer analysis should be performed to confirm these findings.

Question 14

A known hemophiliac has developed an inhibitor. The physician in charge of his care wants to know how much inhibitor is present to properly treat him. What two lab tests would be ordered to assess this?

A) APTT; factor assay
B) Factor VIII: C level; Bethesda titer
C) VWF antigen; Bethesda titer
D) Type and screen; factor assay

Question 15

Predict results that will confirm the patient's diagnosis.

A) Abnormal aggregation with Ristocetin
B) An increased D-dimer
C) Decreased activity of either factors VIII or IX
D) The presence of an inhibitor pattern in a mixing study

Question 16

What should be the next course of action in investigating these results?

A) Repeat the aggregation studies
B) Start the patient on Coumadin
C) Order factor assays of the intrinsic pathway
D) Order factor assays of the intrinsic, extrinsic, and common pathways

Question 17

Hemophilia A is caused by a deficiency in which of the following proteins?

A) von Willebrand's factor
B) Factor VIII
C) Factor IX
D) Glycoprotein IIb/IIIa

Question 18

A physician has confirmed von Willebrand's disease in a patient. Further testing is needed to determine which subtype the patient has. Multimer analysis is performed and comes back normal. What is the most probable explanation for this?

A) The patient is not suffering from von Willebrand's disease.
B) The patient is suffering from type I VWD.
C) The patient has BSS.
D) The wrong patient was drawn.

Question 19

A 34-year-old woman has just given birth to a healthy baby boy. After the delivery of the baby, the physician proceeds to deliver the placenta. After it has been extracted from the mother's uterus, the resident examines it and notes that it appears incomplete. They try to deliver the remainder but are unsuccessful. A few moments later, the mother loses consciousness, and is bleeding profusely from her uterus. Blood is collected, and the results follow. PT: 17 sec (RR: 11.3-12.8 sec)
INR: 3.02
APTT: 67 sec (RR: 23-32 sec)
D-dimer: 540 ng/mL (RR: <400 ng/mL)
Fibrinogen: 82 mg/dL (RR: 200-400 mg/dL)
Factor V assay: 12%
Based on this information, from what is the most probable diagnosis?

A) Hemophilia A
B) von Willebrand's disease
C) Placenta previa
D) DIC

Question 20

Which of the following is used in the identification of a secondary hemostatic pathway anomaly?

A) Bleeding time
B) ACE activity
C) Platelet aggregation studies
D) Factor assays

Question 21

Deficiencies of the fibrin-forming proteins often have a delayed bleeding symptom that results from which of the following?

A) Excessive bleeding from a traumatic injury
B) Bleeding from rupture of small arterioles
C) Formation of hematomas
D) Absence of hemostatic plug stabilization with fibrin

Question 22

What plasma factor levels of the deficient factor can be expected in a female carrier of FVIII or FIX deficiency?

A) 25% of the normal plasma levels
B) 12.5% of the normal plasma levels
C) 50% of the normal plasma levels
D) 5% of the normal plasma levels

Question 23

Which is the most common FVIII mutation in patients with a severe phenotype (occurring in almost 50% of patients)?

A) Gross deletion of entire gene locus
B) Point mutation involving the thrombin cleavage site
C) Inversion mutation of intron 22
D) Point mutation involving the site of VWF attachment

Question 24

Which of the following laboratory assays would be useful in identifying the presence of primary fibrinolysis?

A) Fibrinogen and FDP
B) FDP and D-dimer
C) D-dimer and plasmin
D) Fibrinogen and platelet count

Question 25

How does von Willebrand's disease (VWD) differ from Bernard-Soulier syndrome? Correlate the pathophysiology of both disorders in your response. Name at least two laboratory tests that differentiate each.

Question 26

Explain why disseminated intravascular coagulation is not a primary disease state. Correlate etiology, pathophysiology, and laboratory analysis in your response.

Question 27

Explain the inheritance pattern of the following disorders and how it contributes to the clinical manifestations of each:
a. Hemophilia A
b. Hemophilia B
c. von Willebrand's disease
d. Bernard-Soulier syndrome

Question 28

Explain how liver disease can be differentiated from DIC through laboratory test analysis.

Question 29

Which assay would assess for the presence of a circulating nonspecific inhibitor?

A) Bethesda titer
B) Factor-specific inhibitor
C) Lupus anticoagulant
D) D-dimer

Question 30

An advantage of prenatal diagnosis by genotypic analysis for hemophilia over phenotypic analysis is:

A) ABO blood type does not affect the analysis
B) A chorionic villus biopsy can be tested at 4 weeks gestation
C) Direct DNA diagnosis is available for all families
D) It can be done as a point-of-care test

Question 31

What type of VWD is the only type to have a decreased platelet count?

A) Type 1
B) Type 3
C) Type 2B
D) Type 2N