Thrombosis Flashcards
Homocysteinuria due to deficiency in which enzyme
cystathionine beta synthase
normally:
homocysteine –> cystathionine
Ways to get elevated homocysteine
vit B12 or folate deficiency -normally: -homocysteine --> methionine via B12 -def means can't convert or homocysteinuria -cystathionine beta synthase deficiency
Sx of homocysteinuria
vessel thrombosis, retardation, lens dislocation, long slender fingers, marfanoid habitus
Besides DVT, hypercoag state can lead to thrombosis where else
cerebral veins
hepatic vein: Budd-Chiari and nutmeg liver
Protein C or S deficiency
etiology
complications
medication reactions
proteins C and S normally inactivate V and VIII
C and S have shortest t1/2 of all factors, makes sense if you want to be able to clot quickly
increased risk of warfarin-induced skin necrosis
Etiology of warfarin-induced skin necrosis
thrombosis in skin
because C and S have shortest t1/2 so they will disappear first, temp hypercoag state
very risky in pts with C or S deficiency, b/c they already have low C and S
Factor V Leiden mutation
can’t turn it off
mutation at site where C normally cleaves to inactivate Factor V
Factor V keeps complementing X
coagulation cascade keeps going uncontrolled
Prothrombin 20210A
increases thrombin expression
hypercoag state
ATIII deficiency
normally released from endothelial cells
heparin has little effect in this case, need high doses
b/c heparin acts by increasing activity of ATIII
Which coag pathology does not respond to heparin
ATIII deficiency
because heparin acts by increasing activity of ATIII
How do oral contraceptives increase risk of thrombosis
increase production of coag factors
How do you tell if a thrombus was made pre- or post-mordum
presence of Lines of Zahn = before death
lines of Zahn are made of alternating layers of platelets/fibrin and RBCs
