Protein C deficiency

• Decrease in Protein C activity
  • Inherited
    • Heterozygous for a genetic defect that reduces protein C levels, activity, or both
  • Acquired
    • Disseminated intravascular coagulation (DIC)
    • Liver disease
    • Vitamin K antagonist (VKA) anticoagulants
    • Meningococcal infection
• Diagnosis
  • Protein C activity levels (low in heterozygotes, ~50% of normal).
  • Not accurate during warfarin therapy; consult testing laboratory.
• Management
  • VTE - if unprovoked typically life long anticoagulation