Thrombophilia

Question 1

What is Virchow’s Triad?

Answer 1

Stasis
Vessel wall injury
Hypercoagulability

Question 2

What is the most common cause of inherited thrombophilia?

Answer 2

Factor V Leiden

Question 3

What causes Factor V Leiden?

Answer 3

Autosomal dominant variation in factor V that causes it to inactivate more slowly, leading to more clots
Also does not assist in degredation of VIIIa and Va, causing decreased anticoagulant activity of protein C

Question 4

What lab test will be associated with Factor V Leiden?

Answer 4

Short PTT

Question 5

What are the vitamin K dependent proteins?

Answer 5

Factors II, VII, IX, and X
Proteins C and S

Question 6

What does a prothrombin gene mutation cause?

Answer 6

High prothrombin and low thrombin levels

Question 7

What is protein C deficiency?

Answer 7

Autosomal dominant condition that causes widespread venous thrombosis and skin necrosis

Question 8

What is a complication of protein C?

Answer 8

Warfarin induced skin necrosis

Question 9

How do you treat warfarin induced skin necrosis?

Answer 9

Stop warfarin
Start Vitamin K
Start Heparin
Give protein C concentrate or FFP

Question 10

What does protein C do?

Answer 10

regulates FVIIIa and FVa

Question 11

What are the PT/PTT values for protein C deficiency?

Answer 11

Heterozygous- both normal
Homozygous - PT and PTT prolongation

Question 12

What is the significance of being a vitamin K dependent protein?

Answer 12

Any disorder associated with vitamin K deficiency may result in vitamin K dependent factor deficiency (warfarin use, liver disease, malnutrition, DIC, nephrotic syndrome)

Question 13

What is protein S?

Answer 13

Cofactor for protein C

Question 14

What is the cause of protein S deficiency?

Answer 14

Autosomal dominant mutation or acquired via pregnancy, OCP, Sickle Cell, inflammation, nephrotic syndrome, coumadin therapy

Question 15

What is the cause of antithrombin III deficiency?

Answer 15

Autosomal dominant mutation

Question 16

What is antithrombin III?

Answer 16

Inactivates thrombin and IXa, Xa, XIa, XIIa

Question 17

What are triggers for antithrombin III deficiency initial clinical manifestations?

Answer 17

Pregnancy, OCP, surgery, trauma

Question 18

How much does pregnancy increase the risk of venous thromboembolism?

Answer 18

sixfold

Question 19

What increases the risk of thrombosis in pregnancy

Answer 19

Age >35
C section (bc surgery)
Prolonged immobilization (bed rest)
Obesity
Previous thromboembolism
Coexistant thrombophilia

Question 20

What is the mechanism of thrombosis in pregnancy?

Answer 20

Hemostasis/venous stasis - gravid uterus, compression of L iliac vein by R iliac artery
Trauma - c section or vag delivery
Coagulant factors - incr thrombin, fibrinogen, platelet activation, VWF, VII, VIII, C
Decr protein S and ATIII

Question 21

What is the cause of antiphospholipid syndrome?

Answer 21

Acquired autoantibody (aPL), otherwise unknown pathogenesis. Can be 2/2 SLE, infection, autoimmune disease

Question 22

What are the hallmarks of antiphospholipid syndrome?

Answer 22

Thrombotic events and pregnancy complications

Question 23

What is Libman-sacks verrucous endocarditis related to?

Answer 23

Antiphospholipid syndrome

Question 24

What is the treatment for DVT?

Answer 24

Warfarin with a 5 day heparin bridge
Pradaxa
Xarelto
Eliquis
Savaysa