Lecture 8: Thrombophilias Flashcards
What is Virchow’s Triad?
Stasis
Vessel Wall Injury
Hypercoagulability
What is the primary cause of arterial thrombosis?
Platelet and vessel wall injury
What are the primary etiologies of arterial thrombosis?
Bacterial and viral infections
Inflammation
Trauma/injury
What is VT most commonly caused by?
Stasis or hypercoagulability
What are abnormalities of vessel walls?
Vessel wall injury
Atherosclerosis
What are abnormalities of blood flow/stasis?
AFib
LV Dysfunction
Immobility
Vessel occlusion
Hyperviscosity (polycythemia vera)
SCD
Heart valve disease
Indwelling catheters (PICC or femoral line)
What are abnormalities of coagulation?
Protein C or S def
Activated Protein C resistance
AT deficiency
APL antibodies
Malignancy
High dose estrogen/PREGNANCY
What are the inherited causes of thrombophilia in causes of VT?
Factor V leiden mutation
Prothrombin gene mutation
Protein S def
Protein C def
AT def
Dysfibrinogenemia
In what inherited cause of thrombophilia is DVT/PE most common?
Factor V leiden
What is the most common cause of inherited thrombophilia?
Factor V leiden
What demographic is most susceptible to factor V leiden?
White people
How is factor V Leiden inherited?
Autosomal dominant
What is factor 5?
Inactive cofactor activated by thrombin to convert more prothrombin to thrombin.
What is the mechanism of factor V leiden?
Increased coag because its inactivated slower.
Decreased AC because Protein C needs it to function properly.
What is the gold standard for FV leiden diagnoses?
DNA testing.
What is the concern with a prothrombin gene mutation?
High plasma levels of prothrombin (G20210A)
Vit-K dependent.
What is the mnemonic for proteins C & S?
Clot Stoppers
How is protein C def inherited?
Autosomal dominant
What does a homozygous Protein C def cause?
Purpura fulminans neonatalis, which causes widespread VT and skin necrosis.
How common is Protein C def?
1-9% of pts with a VT have Protein C def.
What are patients specifically at risk for in protein C def?
Warfarin-induced skin necrosis.
How do I treat warfarin-induced skin necrosis?
Stop warfarin
Start Vit K, Hep, Protein C concentrate/FFP.
How does Protein C exert an AC effect?
Regulates F8a and F5a
How do heterozygous Protein C def present on labs?
Normal PT/PTT
How do homozygous Protein C def present on labs?
Looks like DIC