Thrombotic Risk Factors--Krafts Flashcards
Factor V Leiden
Pathology
too much factor V
-point mutation in factor V gene
(mutation in portion of factor V normally cleaved and turned off by protein C)
-factor V cannot be turned off
**cannot be cleved by protein C**
What is the most common cause of unexplained thromboses?
Factor V Leiden
Dx of Factor V Leiden
genetic testing
PTT/INR not helpful
Tx of Factor V Leiden
no Tx unless attack or chronic
then anticoag
Normal function of ATIII
bind IIa, VIIa, IXa, Xa, XIa
normally anticoagulant
What normally poteniates ATIII?
heparin
ATIII Deficiency
pathology
decreased amount of ATIII
heparin doesn’t work because there is little ATIII
Protein C and S Deficiencies
rare effects with warfarin
warfarin-induced skin necrosis
purpura fulminans
Protein C
pathology
decreased or defective protein C
Two unique problems in protein C and S deficiencies
warfarin-induced skin necrosis
purpura fulminans
Purpura Fulminans
pathology
thrombotic state
underlying deficiency
sick
–> skin necrosis
Factor II Gene Mutation
pathology
mutation in prothrombin gene
too much prothrombin
normal, excessive prothrombin gene
Homocysteine
normal metabolism
normally converts folate to reduced folate
required for myelin generation
MTHFR deficiency result
methylene tetrahydrofolate reductase
homocysteinemia results
Problems that homocysteinemia causes
toxic to endothelium (ROS)
interferes w/ NO
Antiphospholipid Antibody Syndrome
false tests
prolonged INR, PTT (actually hypercoagulable state)
+ syphillis (in - patients)
+ DAT (when negative)
Antiphospholipid Antibodies
what are they directed against?
IgG antibodies against phospholipids
Why can it be very, very hard to get a good INR on a patient with lupus?
if they have antiphospholipid antibodies, they can have a falsely prolonged INR
dosing warfarin becomes very difficult!
Clot vs Bleed
antiphospholipid antibodies
falsely prolonged INR/PTT
hypercoagulable state (unknown etiology)
Will a PTT mixing study become normal in antiphospholipid antibody syndrome?
no!
there is an inhibitor present
