Interpretation

Inherited Protein C deficiency
- Type I: low antigen + low activity
- Type II: normal antigen + low activity
Liver disease (reduced production)
Vitamin K deficiency
Warfarin (Coumadin) therapy — lowers Protein C levels temporarily
DIC (disseminated intravascular coagulation)
Severe infection or sepsis
Kidney disease (protein loss)

High levels usually have no clinical significance and are not associated with increased risk.