Brainscape's Knowledge GenomeTM

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


See full index

Haematology > Thrombophilia > Flashcards

Thrombophilia Flashcards

1
Q

Define thrombophilia

A

Thrombophilia (aka hypercoagulability) is when the normal physiological balance between clot formation and clot lysis becomes tipped towards clot formation

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

What is the most common presentation of thrombophilia?

A

Venous thromboembolism e.g. DVT and PE

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

Thrombophilia is a part of Virchow’s triad for risk factors for thrombosis. What are the other two risk factors in this triad?

A

Endothelial injury / damage

Stasis

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

Give example of genetic (inherited) causes of thrombophilia?

A

Factor V leiden
Protein C / protein S deficiency
Prothrombin gene mutation

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

Give an example of an acquired cause of thrombophilia?

A

Antiphospholipid syndrome

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

In which patients with VTE should thrombophilia be screened for?

A

VTE <40 years
More than one VTE
VTE in an unusual location e.g. mesenteric veins
Women with recurrent miscarriages

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

What pattern of inheritance does factor V Leiden follow?

A

Autosomal dominant

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

What is the most common genetically acquired hyper coagulability disorder in caucasians?

A

Factor V Leiden

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

Describe the pathophysiology of factor V Leiden.

A

AD condition in which there is a single point mutation in the gene for factor V
This mutation results in a misshapen cleavage site on factor V meaning that factor V cannot be inactivated

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

How will APTT be affected by factor V Leiden?

A

Normal or shortened

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

Describe the use of a functional assay in the diagnosis of factor V Leiden

A

APTT is measured before and after mixing plasma with purified protein C
Normally, this should not change APTT but in factor V Leiden this will prolong APTT

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

What is the golf standard diagnostic test for factor V Leiden?

A

DNA testing

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

Describe the aetiology of protein C or protein s deficiencies

A

AD inherited disorders

Can also. be caused by acute thrombosis, DIC, liver disease, HIV infection, nephritic syndrome and vitamin K antagonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe how deficiency in protein C or protein S can cause hypercoagulability

A

Protein C is a vitamin-K dependent inhibitor of factors V and VII and so a deficiency in protein C or its co-factor (protein S) causes unregulated activation of the coagulation cascade

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

Describe the management of genetically inherited thrombophilias

A

Treatment with anticoagulant / thrombolytic medication is required when VTE develops
VTE prophylaxis is required in certain situations eg. during surgery / pregnancy or if multiple thrombophilic mutations co-exist
Patients should also avoid other risk factors for thrombosis e.g. oral contraceptive pill

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the second most common inherited thrombophilia?

A

Prothrombin gene mutation

17
Q

Describe the pathophysiology of prothrombin gene mutation thrombophilia

A

This is an AD mutation which results in an increase in the circulating levels of prothrombin

18
Q

In addition to the increased risk of thrombosis, what is the other outcome of antithrombin III deficiency?

A

Insensitivity to heparin

19
Q

What can cause acquired antithrombin II deficiency?

A

Impaired production of antithrombin III due to liver disease

Protein losses in nephrotic syndorme or DIC

20
Q

What is the inheritance mechanism of genetic antithrombin III deficiencies?

A

Autosomal dominant

21
Q

What is antiphospholipid syndrome?

A

An autoimmune condition where individuals produce antiphospholipid antibodies which attacks phospholipids in the cell membrane. This leads to a hyper coagulable state

22
Q

Secondary antiphospholipid syndrome occurs with other autoimmune disease. In particular, what AI condition is antiphospholipid syndrome associated with?

A

Systemic lupus erythematosus

23
Q

Antiphospholipid syndrome can develop due to a combination of genetic and environmental factors. Give examples of these factors

A

Genetic - HLA-DR7 gene

Environmental - infections (syphilis, hepatitis C, HIV, malaria), drugs (propranolol, phenytoin)

24
Q

What is the main antiphospholipid antibody?

A

Anti-beta 2 glycoprotein I

25
Q

Explain how anti beta 2 glycoprotein 1 antibody in antiphospholipid syndrome causes thrombosis?

A

It targets the protein beta 2 glycoprotein 1 which normally inhibits agglutination of platelets. Thus the antibody binds to and inhibits this protein to cause clot formation

26
Q

Which antiphospholipid antibody is also present in syphillis and so can cause a false-positive test for this infection?

A

Anti-cardiolipin

27
Q

Antiphospholipid antibodies lead to a hyper coagulable state. In males, this most commonly manifests as arterial thrombosis. What conditions can result from this?

A

MI
Stroke
Limb ischaemia

28
Q

Antiphospholipid antibodies lead to a hyper coagulable state. In females, this most commonly manifests as venous thrombosis. What conditions can result from this?

A

DVT

PE

29
Q

Livedo reticularis is a typical skin finding in antiphospholipid syndrome. Describe the appearance of livedo reticularis and how this is caused?

A

Appearance - a mottled purplish discolouration

Caused by swelling of venues due to obstruction by clots

30
Q

Antiphospholipid antibodies can cause neurological symptoms such as…?

A

Headaches

Seizures

31
Q

Diagnosis of antiphospholipid syndrome requires one clinical and one diagnostic criteria to be met. What are the clinical criteria?

A

History of thrombosis

History of pregnancy complications

32
Q

Diagnosis of antiphospholipid syndrome requires one clinical and one diagnostic criteria to be met. What are the diagnostic criteria?

A

Presence of anticardiolipin
Presence of anti beta 2 glycoprotein 1 antibodies
Presence of lupus anticoagulant

33
Q

What is lupus anticoagulant?

A

A antiphospholipid antibody

It is often found in people with SLE and acts as an anticoagulant in vitro but as a pro-thrombotic in vivo

34
Q

Describe the management of antiphospholipid syndrome.

A

Prevention of thrombosis with aspirin and avoiding risk factors (e.g. oral contraceptive pill, smoking)
Warfarin used as an anticoagulant when thrombosis occurs
Corticosteroids can help lift the immmune response in people with non-thrombotic manifestations or other associated AI diseases

Haematology (10 decks)

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