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Flashcards in 2.1 Thrombophilia Deck (26):
1

What are the three components of thrombus formation?

Hypercoaguability
Abnormal blood flow
Endothelial damage

2

What are the genetic risk factors for vein thrombosis?

AT deficiency. PC and PS deficiency, FV Leiden, APCR, ProThrombin G20210A, MTHFR mutation, increased VIIIc

3

What are the acquired risk factors for vein thrombosis?

Cancer, surgery, acute illness with bed rest
Pregnancy/puerperium, hormonal preparations (OCP), obesity, autoimmune disease, elevated homocysteine

4

Define thrombophilia

abnormal occurrence of vein thrombosis without adequate provocation

5

Define thrombophilia

abnormal occurrence of vein thrombosis without adequate provocation

abnormal = young patients, unprovoked, recurrent, unusual sites, family history

6

What are the coagulation factors?

I: Fibrinogen
II: Prothrombin
III: Tissue Factor or Thromboplastin
IV: Ca
V: Labile factor
VII: Proconvertin
VIII: Antihemophilic factor
IX: Christmas factor
X: Stuart or Stuart-Prower factor
XI: Plasma thromboplastin antecedent
XII: Hageman factor, contact factor
XIII: Fibrin stablizing factor

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7

What are the genetic risk factors for vein thrombosis?

AT deficiency
Protein C and Protein S deficiency
FV Leiden
APCR
ProThrombin G20210A, MTHFR mutation
Increased VIIIc

8

What are the coagulation factors?

I: Fibrinogen
II: Prothrombin
III: Tissue Factor or Thromboplastin
IV: Ca
V: Labile factor
VII: Proconvertin
VIII: Antihemophilic factor
IX: Christmas factor
X: Stuart or Stuart-Prower factor
XI: Plasma thromboplastin antecedent
XII: Hageman factor, contact factor
XIII: Fibrin stablizing factor

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9

What is fibrinolysis?

The breakdown of clots from plasmin (fibrin degradation products)

10

What factors promote the production of plasmin from plasminogen?

tPA (from endothelial cells) and Urokinase Streptokinase

11

What is the clinical definition of thrombophilia?

Patients who develop PE spontaneously, VTE is out of proportion to any recognised stimulus, recurrent venous thrombosis and developing venous thromboembolism at an early age

12

What patients have been shown to have high rates of VTE?

Cancer patients (20% new cases associated with cancer) - especially those with pancreatic and stomach cancer

13

What is antiphospholipid syndrome?

A non inflammatory auto immune disease in which there is presence of antibodies against anionic phospholipids. Associated with the occurrence of venous and arterial thrombosis and/or recurrent miscarriage.

14

What are the most common antibodies directed against in antiphospholipid syndrome?

B2 glycoprotein 1 and prothrombin
(anti B2 glycoprotein 1 antibodies)

15

What do the antiphospholipid antibodies do?

Inhibit the inhibiting factors of the coagulation cascade.

Interfere with coagulation and anticoagulation pathways and activation of platelets.

Endothelial activation in vessels

16

Why does deficient protein C usually occur?

resistance of factor Va to be cleaved by activated protein C leading to excessive levels of factor V stimulating clotting

Usually because of Factor V Leiden mutation

17

What mutation leads to elevated prothrombin?

mutation at position 20210

18

What is the role of antithrombin?

form a 1:1 complex with activated clotting factors (thrombin and Xa) at the active site thus preventing the protease enzymes that would normally bind from doing so.

19

When does antithrombin accelerate its action?

In the presence of heparin or when it is activated by cell surface heparin sulfate

20

What two factors does protein C inhibit?

factor Va and VIIIa

21

What is the role of protein S?

to act as a cofactor for protein C in the inactivation of FVa and FVIIIa

22

When do you usually test for thrombophilia?

1 month after commencing therapy

23

When do you usually test for thrombophilia?

1 month after completion therapy

24

Who do you normally test for thrombophilia?

Recurrent/spontaneous PE or DVT
Thrombosis at young age
Family history or thrombosis at unusual site

25

What tests do you use to evaluate thrombophilia

FBC, FCP (clotting) and ESR
Factor V leiden (ACPR)
Prothrombin mutation
AT
Protein C and S
Lupus anticoagulant

26

Which two abnormalaties will cause both arterial and venous clotting?

Hyperchromocysteinemia and Lupus anticoagulant