JamunJar: Health & Wealth for a better tomorrow

🧪 What is Protein S Activity?

Protein S is a vitamin K–dependent plasma glycoprotein that serves as a cofactor to activated Protein C in the anticoagulant pathway, helping to regulate blood clotting by inactivating clotting factors Va and VIIIa.
The Protein S Activity test measures the functional activity of Protein S in the blood.

❓ Why is the Test Done?

To:

Diagnose Protein S deficiency (hereditary or acquired), which increases the risk of venous thromboembolism (VTE)
Evaluate causes of unexplained or recurrent blood clots
Assess thrombophilia (tendency to form clots)
Monitor effects of vitamin K antagonists or liver disease on Protein S levels

📊 Normal Range

Protein S Activity	Reference Range
Adults	60% – 150% (varies by lab)

📈 Interpretation of Results

Result	Possible Meaning
Low Protein S Activity	Suggests Protein S deficiency → increased thrombosis risk
Normal or High Activity	Normal anticoagulant function
Acquired deficiency	Seen in liver disease, vitamin K deficiency, warfarin therapy

🧠 Associated Conditions

System/Organ	Conditions
Hematologic	Venous thromboembolism, deep vein thrombosis, pulmonary embolism
Liver	Liver disease affecting synthesis
Coagulation system	Disseminated intravascular coagulation (DIC), vitamin K deficiency

🔄 Related / Follow-Up Tests

Protein C Activity
Antithrombin III levels
Factor V Leiden mutation
Prothrombin gene mutation
Coagulation profile (PT, aPTT)
D-dimer

✅ Fasting Required?

Test	Fasting Required
Protein S Activity	❌ No

📝 Summary Table

Parameter	Details
What	Functional assay of Protein S anticoagulant activity
Why	Evaluate thrombophilia risk due to Protein S deficiency
Normal Range	60% – 150%
Low Levels	Hereditary or acquired deficiency
Associated Conditions	Venous thromboembolism, liver disease, vitamin K deficiency
Follow-up Tests	Protein C, antithrombin III, genetic testing, coagulation studies
Fasting Required	❌ No

Protein S Activity

1000+ Booked this Test