Hematology Week 2: Introduction to Thrombophilia Flashcards
Virchow’s Triad
3 listed
- Alteration of blood flow
- Endothelial injury
- Hypercoagulable state (inherent/acquired)
VTE AKA
Venous Thromboembolism
Thrombosis High-Risk Patients
3 listed
- Males
- >55
- recently hospitalized
DVT AKA
Deep Venous Thrombosis
circulatory stasis involves
alteration of blood flow
Circulatory stasis: Things that contribute to a clot in arteries
Turbulence
Circulatory stasis: Things that contribute to a clot in venous
Stasis
Circulatory stasis
Arterial: turbulence
Venous: Stasis
Alteration of blood flow consequences
Disruption of laminar flow via stasis or turbulence
- allows platelets to interact with endothelium
- activates endothelium
- prolongs exposure of activated clotting factors
Common Causes of Alteration of blood flow in the arteries/cardiac/aortic
3 listed
- Aneurysms
- Dilated atrium
- Ulcerated atherosclerotic plaques
Causes of Altered blood flow in the venous system
9 listed
- Prolonged immobilization
- Paget-Schroetter syndrome axial or subclavian vein can be compressed
- Clot in iliac veins (pregnancy) left iliac vein is compressed by the right iliac artery
Common Causes of Hyperviscosity
3 listed
- polycythemia (primary, secondary)
- Sickle Cell Anemia
- Increased plasma proteins
Causes of arterial endothelial injury
12 listed
commonly affected due to high flow rates
Indications for inheritable Hypercoagulable States
5 listed
age <40
unprovoked thrombosis
FHx of thrombosis
Thrombosis at an unusual site
Contraindicators of inherited hypercoagulable states
NOT associated with arterial thrombosis (Stroke, TIA, MI, etc)
Inherited hypercoagulability conditions
5 listed
- Factor V Leiden
- Factor II hyperprothrombinemia
- AT deficiency
- Protein C deficiency
- Protein S deficiency
Procoagulant gains of function conditions
2 listed
- Factor V Leiden
- Factor II hyperprothrombinemia
inherited conditions with a weaker risk of VTE
2 listed
- Factor V Leiden
- Factor II hyperprothrombinemia
Factor V Leiden Genetic inheritance pattern
- Autosomal Dominant
- can be traced back to a single mutational event 25k years ago
accounts for half of all heritable thrombophilias
Factor V Leiden
Found in 12-18% of all patients with VTE
Factor V Leiden
Factor V Leiden subtype increased risks
Heterozygotes patients with a NON-O BLOOD TYPE have more FVIII and have 2-4x more risk of VTE
Risk of recurrence of VTE with Factor V Leiden
Negligible recurrence risk
Risks of heterozygotes of Factor V Leiden
5% will have VTE
non-O blood type has increased risks
What does Factor 5 do?
factor 5 associated with factor 10 to link the intrinsic and extrinsic pathways
Factor V in Factor V Leiden
Factor V is less susceptible to the inhibition of the anticoagulant protein Protein C
Factor V Leiden Etiology
arginine to glutamine substitution at R506
Factor II Hyperprothrominemia Genetic inheritance and consequences
- Autosomal dominant
- nearly exclusively caucasian
- 3-4 fold increased risk of thrombosis
Factor II Hyperprothrombinemia Genetics
Autosomal Dominant
Factor II Hyperprothrombinemia VTE recurrence risk
Negligible recurrence risk
Factor II Hyperprothrombinemia Pathophysiology
gain of function mutation in 3’ unstranslated region resulting in increased plasma prothrombin levels by 25%
Factor II Hyperprothrombinemia gene
prothrombin 20210A untranslated region causing high efficiency mRNA
More rare inherited conditions of hypercoagulability
3 listed
- AT Deficiency
- Protein C deficiency
- Protein S Deficiency
inherited conditions of hypercoagulability with greater risk of VTE
3 listed
- At Deficiency
- Protein C Deficiency
- Protein S Deficiency
Inherited conditions of hypercoagulability that are measured by activity or antigen levels
3 listed
At Deficiency
Protein C Deficiency
Protein S Deficiency
Protein C Deficiency Genetics
Autosomal Dominant >160 mutations