Step I Protein C/S deficiency

[super87]

FA 2013 pg 360: under Hereditary thrombosis syndrome leading to hypercoagulability. In protein C or S deficiency, it says "increased risk of thrombotic skin necrosis with hemorrhage following administration of warfarin"

Can someone explain why?

 

[bangarang]

FA 2013 pg 360: under Hereditary thrombosis syndrome leading to hypercoagulability. In protein C or S deficiency, it says "increased risk of thrombotic skin necrosis with hemorrhage following administration of warfarin"

Can someone explain why?

Protein C is an anticoagulant with a shorter half-life than some of the coagulation factors > administer warfarin > deplete protein C first > temporary hypercoagulable state > blood clot to skin's blood supply > necrosis.

 

[SLC]

FA 2013 pg 360: under Hereditary thrombosis syndrome leading to hypercoagulability. In protein C or S deficiency, it says "increased risk of thrombotic skin necrosis with hemorrhage following administration of warfarin"

Can someone explain why?

Because Protein C and S are both vitamin K dependent (anti-clotting) factors. And Warfarin affects them stronger at first. (Protein C has the shortest half life of all the VitaminK dependent factors)

In patients with protein C and S deficiency, there is an increased risk of skin necrosis because of the above.

Interestingly, because PT measurement is mostly based on FactorVII, it's possible that a patient can have a "therapeutic PT" and still be hyper-coagulable initially.

 

[super87]

Thank you! that was helpful 🙂