Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Unit 2 SPATH UFCOM > J. Thrombophilia (L8 & L10) > Flashcards

J. Thrombophilia (L8 & L10) Flashcards

1
Q

What is Thrombophilia?

A

• An increased risk of thrombosis that is inherited or acquired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Is Thrombophilia usually inherited or acquired?

A

• Mostly acquired (3/4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many people with Thrombophilia have a symptomatic thrombosis? Why ?

A
  • A relatively low percentage of people with thrombophilia get thrombosis
  • Usually some sort of event is needed to trigger thrombosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What percentage of people with Venous Thromboembolism have Thrombophilia?

A
  • About 80%

* Most people with thrombophilia do not get thrombosis, but most people with thrombosis do have thrombophilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the lab test for Thrombophilia?

A

• There isn’t one test that definitely diagnosis thrombophilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are PTT, PT and platelet function tests affected by Thrombophilia?

A

• Usually normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How is fibrinogen affected by Thrombophilia?

A

• May or may not be affected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How is the treatment plan altered when thrombosis is seen in somebody with Thrombophilia?

A

• Treatment is no different than any other patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why are a majority of hospital patients at increased risk for Thrombosis?

A

• Surgery, trauma, immobilization and inflammation all increase the risk for thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do inflammation/surgery/trauma lead to thrombosis?

A
  • Cytokines –> increase in factor VIII, VWF and fibrinogen

* Hospitalization –> immobilization –> stasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can you test is a hospital patient of pregnant woman/woman on contraceptives are at an increased risk for thrombosis?

A

• Can’t test for this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does malignancy increase the likelihood of Thrombosis?

A
  • Inflammatory cytokines increase chances of thrombosis

* Tumors can produce tissue factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

List the different type of inherited Thrombophilia:

A
  • Antithrombin III deficiency
  • Protein C deficiency
  • Protein S deficiency
  • Factor V Liden Mutation
  • Prothrombin 20210A Mutation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the general pathophysiology of the inherited Thrombophilias?

A

• Some sort of dysfunction or deficiency of the body’s natural anticoagulants –> predispose to thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Antithrombin III? What is it’s function? Where is it created? How would you describe the half life of Antithrombin III?

A
  • Serine Protease inhibitor –> binds factor –> cleared by liver –> deficiency in multiple clotting factors –> natural anticoagulant
  • Mainly targets thrombin/factor II (hence the name) and factor X
  • Liver
  • Long (70 hours)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the mode of action for Heparin?

A

• It potentiates the action of Antithrombin III 1000 times

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the pattern for inheritance for inherited Antithrombin III Deficiency? What if heterozygous? What if homozygous?

A
  • Autosomal dominant
  • Heterozygous has disease
  • Homozygous is fatal lethal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How common is Inherited Antithrombin III deficiency?

A

Relatively rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How is Antithrombin Deficiency diagnosed? What does the disease cause?

A
  • Antithrombin activity

* Increased likelihood of venous thrombosis especially during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can Antithrombin Deficiency be acquired?

A
  • Impaired synthesis = liver disease, malabsorption, burns, premature babies
  • Increased consumption = DIC, sepsis, nephrotic syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What condition can give you a false positive for Antithrombin III deficiency?

A

• Acute thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What nutrient is needed for the synthesis of Protein C and Protein S?

A

Vitamin K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why are Protein C & Protein S levels low in a patient taking Warfarin/Coumadin?

A

Both are Vit K dependent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the function of Protein C? What does a deficiency predispose somebody to?

A
  • It is a natural anticoagulant that binds Proteins S –> converts active factor V & VIII into their inactive forms
  • Venous thrombosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where is Protein C created? How would you describe its half-life?

A
  • Liver

* Very short half-life (7 hours)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What 2 things need to happen to Protein C before it can be functional?

A
  • It must be converted to Activated Protein C (APC) first as it is secreted as an inactive zymogen precursor
  • APC then needs to bind Protein S before it can inactivate coagulation factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the pattern of inheritance for Inherited Protein C Deficiency? How common is the inherited form?

A
  • Autosomal dominant

* Rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How is Protein C deficiency diagnoses? What can give a false +?

A
  • Protein C functionality test

* Warfarin/Coumadin or acute thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What causes Acquired Protein C Deficiency?

A
  • Decreased synthesis = Liver disease, low vit K

* Increased consumption = DIC, sepsis

30
Q

Where is Protein S synthesized?

A

• Liver, megakaryocytes and endothelium

31
Q

What is the function of Protein S? How would you describe its half-life?

A
  • Act as a cofactor to Protein C –> natural anticoagulant which inactivates factor V & VIII
  • Long (100 hours)
32
Q

How is Protein S deficiency diagnosed?

A

• Protein S functional activity

33
Q

What causes Acquired Protein S Deficiency?

A
  • Pregnancy
  • Oral contraceptives
  • Decreased production = liver disease low Vit K
  • Increased consumption = DIC, sepsis, acute thrombosis
34
Q

What is prothrombin? Where is it synthesized? What is needed for it’s synthesis?

A
  • Coagulation factor II
  • Liver
  • Vit K
35
Q

What is Prothrombin Mutation? What is the general pathophysiology? How is this different than the other inherited Thrombophilias?

A
  • Gain of function mutation –> more prothrombin –> increases likelihood of thrombosis
  • The other types are a loss of a natural anticoagulant, while this disorder is an increase in a natural coagulant
36
Q

How common is Prothrombin Mutation? What population is it most common in?

A
  • Pretty common (2%)

* Caucasians

37
Q

How is Prothrombin mutation diagnosed? What can give a false positive?

A
  • DNA genotyping

* Nothing, no drugs or conditions change the DNA to give a false positive

38
Q

What is Factor V Leiden? What is the general pathophysiology?

A
  • Point mutation –> V resistant to inactivation by Protein C –> V stays active –> thrombosis
  • Activate Protein C (APC) Resistance
39
Q

How common is Factor V Leiden? What population is it common in?

A
  • Pretty common (5% heterozygous)

* Caucasians

40
Q

What is the difference between heterozygous and homozygous Factor V Leidin?

A
  • Heterozygous have about a 4 fold increased risk of thrombosis
  • Homozygous have about an 80 fold increased risk of thrombosis
41
Q

Hereditary thrombophilias are associated with which type of thrombosis?

A

• Venous (not arterial)

42
Q

What causes acquired Thrombophilia?

A
  • Cancer
  • Trauma or recent surgery
  • Immobilization
  • High Estrogen (oral contraceptives or pregnancy)
  • HIT
  • TTP
  • Antiphospholipid syndrome
43
Q

What is Antiphopholipid Syndrome?

A

• Acquired autoimmune disease against phospholipid or proteins attached to phospholipids

44
Q

What are Antiphospholipid Antibodies?

A
  • Ab against phospholipids and proteins bound to phospholipids
  • Can be elevated transiently without being a problem
45
Q

What Thrombophilia can cause arterial thrombosis (for example in a young person)?

A

• Antiphopholipid Syndrome

46
Q

How is Antiphopholipid Syndrome diagnosed?

A

• Need lab criteria (Ab) & clinical criteria (symptoms of thrombosis)

47
Q

If have Antiphospholipd syndrome how will PTT present? What about with a mixing study?

A
  • Prolonged

* Not corrected

48
Q

Antiphospholipid Syndrome can be secondary to what conditions?

A
  • Lupus
  • HIV
  • Cancer
  • Certain medications
49
Q

What is the most important Antiphopholipid Antibody?

A

Lupus anticoagulant

50
Q

Stroke is associated with what type of Thrombophilia?

A

Antiphospholipid syndrome

51
Q

What is the general pathophysiology of miscarriages in antiphosphpolipid syndrome?

A

• Thrombosis in placenta –> insufficiency blood to or from the fetus

52
Q

What is confusing about coagulation testing for Antiphospholipid syndrome?

A
  • PTT is actually prolonged, but in the body it causes thrombosis = not intuitive
  • PT is normal
  • PTT does not correct with mixing study
53
Q

What autoimmune disease is antiphopholipid syndrome most often associated with?

A

Lupus

54
Q

What are the 3 main antibodies present in Antiphopholipid syndrome?

A
  • Lupus anticoagulant
  • Cardiolipin Antibody
  • Beta-1 Glycoprotein Antibody
55
Q

What is a Lupus Anticoagulation Assay?

A

• If PTT is abnormal and Antiphospholipid syndrome is suspected –> add excess phospholipid –> PTT corrected somewhat as excess overcomes inhibition of antibody

56
Q

Thrombosis can be a warning sign of what serious medical condition?

A

Cancer

57
Q

What 2 risk factors for Thrombosis are particularly important in women?

A
  • Pregnancy

* Oral contraceptives

58
Q

How does pregnancy cause increased thrombosis?

A
  • Increase in coagulation factors and decrease in Protein S
  • C section surgeries
  • Stasis as vessels are compressed
59
Q

What is the most common cause of thrombosis in young women?

A

Oral contraceptives

60
Q

What are the 2 things that need to be present to diagnos Thrombotic Thrombocytopenic Purpura (TTP)? What else may be present?

A
  • Thrombocytopenia & microangiopathic hemolytic anemia (schistocytes)
  • Neurologic symptoms or renal dysfunction
61
Q

What is the general pathophysiology of TTP?

A
  • Adams 13 cuts VWF factor into smaller pieces to decrease its affinity for platelets
  • Genetic or Ab mediated decrease in Adama13 –> large “sticky” VWF that cause microthrombi –> cosumes platelets (thrombocytopenia) and causes schistocytes
62
Q

What disorder is very similar to TTP but is seen in children and does not have an ADAM13 related problem?

A

Hemolytic Uremic Syndrome (HUS)

63
Q

What is a simple 2 word definition of HIT?

A

“Allergy” to heparin

64
Q

What types of thrombosis can HIT cause?

A

Venous and arterial

65
Q

Why is the platelet count of HIT confusing?

A
  • There is thrombocytopenia, but it is related with thrombosis not bleeding
  • Platelets are being consumed –> there are platelets in the body just not in the blood
66
Q

What is the general pathophysiology of Heparin Induced Thrombocytopenia (HIT)?

A
  • Antibodies created against haprin-factor 4 complex –> antibody binds complex and then binds platelet –> platelet is then removed by macrophages –> thrombocytopenia
  • Antibody binding to Fc receptor on platelet activates platelet –> thrombosis
67
Q

How is HIT diagnosed?

A

Elisa for Heparin-factor 4 antibody

68
Q

Who should be screened for Thrombophilia?

A

• Should only test high risk people with clots at early age, family history of clotting, clots in unusual locations, idiopathic or recurrent venous thromboembolism

69
Q

What tests are generally performed when trying to determine the source of Thrombophilia?

A
  • Protein C activity
  • Protein S activity
  • Antithrombin III activity
  • Factor V Leidin DNA mutation test
  • Prothrombin Gene Mutation DNA analysis
  • Plasma Lupus Anticoagulant
  • Plasma Anticardiolipin Ab
  • Plasma Anti B2 Glycoprotein Abs
70
Q

How do you test to see if a thrombosis has already occurred? (Not if there is an increased risk of thrombosis)

A

D-dimer test

71
Q

What is a D-Dimer test?

A
  • When plasmin degrades Fibrin –> D dimers –> + signifies thrombosis has taken place recently
  • Normal D-dimers excludes thrombosis –> used for negative predictive value
72
Q

What is Immune Thrombocytopenic Purpura?

A

Ab against platelets –> ab-plt complex cleared by spleen –> isolated thrombocytonpenia

Asymptomatic because the thrombocytopenia is not severe

Unit 2 SPATH UFCOM (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions