A functional assay for protein C in human plasma.

Area of Science:

• Biochemistry
• Hematology
• Clinical Chemistry

Background:

• Protein C is a crucial anticoagulant vitamin K-dependent plasma protein.
• Dysfunctional or deficient protein C levels are associated with thrombotic disorders.

Purpose of the Study:

• To develop and validate a functional assay for quantifying protein C activity in human plasma.
• To assess protein C levels in various clinical conditions.

Main Methods:

• A functional assay was developed utilizing the ability of activated protein C to prolong the kaolin-cephalin activated partial thromboplastin time.
• Protein C was isolated and activated, followed by measurement of its anticoagulant effect.
• Assay validation involved testing plasma samples from normal subjects and patients with specific diseases.

Main Results:

• The assay demonstrated reliable measurement of protein C activity.
• Normal subjects exhibited a mean protein C level of 94% ± 12% of pooled normal plasma.
• Significantly reduced protein C levels were observed in patients with severe liver disease (28%), disseminated intravascular coagulation (29%), and warfarin therapy (17%).

Conclusions:

• A simple and effective functional assay for protein C activity has been established.
• The assay is suitable for routine clinical laboratory use.
• The findings highlight the diagnostic utility of protein C activity measurement in various hematological conditions.