PROTEIN S ANTIGEN (FREE)

Protein S Antigen (Free): Price, Purpose, Range & Reports

Test Overview

The Protein S Antigen (Free) test is a specialised blood test that measures the active form of Protein S, a natural substance in the body that helps prevent blood clots. Protein S works alongside Activated Protein C to control clotting by turning off certain clotting factors. A deficiency in free Protein S is a key marker for thrombophilia, a condition that increases the risk of abnormal blood clots such as deep vein thrombosis (DVT) and pulmonary embolism (PE). 

Also known as Free Protein S, this quantitative test is critical for establishing a definitive diagnosis of hereditary or acquired Protein S deficiency. It is the preferred initial test over the Total Protein S Antigen test because only the free fraction is functionally active. If you are searching for a reliable Protein S Antigen (Free) price or a convenient test near me, Apollo 24|7 provides accredited laboratory services, ensuring the precision required for accurate hemostasis testing.

What is the Protein S Antigen (Free) Test?

The Protein S Antigen (Free) test is a blood test that specifically measures the concentration of the circulating Protein S that is not bound to C4b-binding protein (C4BP). In the blood, Protein S exists in two primary forms: the inactive, bound form, and the active, unbound (free) form. Since only the free form can effectively partner with Activated Protein C (APC) to break down clots, its measurement is a direct assessment of the available anticoagulant capacity.

Doctors use this test to help confirm or rule out Protein S deficiency. This deficiency can be inherited (Type I, II, or III) or acquired (due to conditions like liver disease, pregnancy, Vitamin K deficiency, or Warfarin therapy). The results are expressed as a percentage of the amount found in normal pooled plasma. Because the test measures the physical quantity (antigen) of the active form, it is highly valuable in classifying the type of deficiency and guiding the long-term management of patients with recurrent or unexplained thrombotic events.

What is the Protein S Antigen (Free) Price?

The Protein S Antigen (Free) test uses advanced immunoassay techniques to accurately measure the free fraction of Protein S in the blood. Several factors can influence the final cost:

• Advanced Testing Methods: The test uses high-precision tools and antibodies, which adds to the cost.
• Location: Prices may vary depending on the city or region due to local lab fees and logistics.
• Home Collection: If you choose to have your sample collected at home, there may be a small extra charge.
• Lab Quality: Getting tested at certified labs like those affiliated with Apollo 24|7 ensures accurate results.

For the most accurate and current Protein S Antigen (Free) price near me, the best way to find out is by checking the Apollo 24|7 websites or mobile applications. Prices are regularly updated based on your location and available service options.

What is the Purpose of the Protein S Antigen (Free) Test?

The primary purpose of the Protein S Antigen (Free) test is to diagnose or rule out Protein S Deficiency, a significant risk factor for venous blood clots.

Doctors recommend the Protein S Antigen (Free) test for the following key objectives:

• Diagnosis of Thrombophilia: To establish a definitive diagnosis in patients with unexplained or recurrent venous thromboembolism (DVT or PE), especially when the clots occur at a young age (less than 50) or in unusual locations (e.g., cerebral or mesenteric veins).
• Family Screening: To screen asymptomatic first-degree relatives (parents, siblings, children) of a patient with a confirmed inherited Protein S deficiency.
• Classification of Deficiency: To help haematologists distinguish between Type I (low total and free protein) and Type III (normal total, low free protein) inherited deficiencies.
• Investigating Neonatal Clotting: To aid in the diagnosis of severe, life-threatening coagulation disorders in newborns, such as Purpura Fulminans.

Who Should Get a Protein S Antigen (Free) Test Done?

You may need a Protein S Antigen (Free) test if you've had blood clots that seem unusual or occurred without a clear cause. This test helps detect a deficiency in Protein S, a natural anticoagulant that keeps your blood from clotting too much. A low level of free Protein S can increase your risk for serious conditions like deep vein thrombosis (DVT) or pulmonary embolism (PE).

Doctors often recommend this test if:

• You've had a clot without typical risk factors like surgery, injury, or long-term immobility.
• You've experienced multiple clotting episodes, especially while not on blood thinners.
• Your first clot happened before age 50.
• You have a family history of clotting disorders or known Protein S deficiency.
• You've had a clot in an unusual location, such as the brain, abdomen, or upper limbs.
• If any of these apply to you, your doctor may suggest this test to better understand your risk and guide your treatment plan.

Components of the Protein S Antigen (Free) Test

This test is focused on the quantitative measurement of the active form of the Protein S molecule in the bloodstream.
The test is performed for:

FREE PROTEIN S ANTIGEN: This parameter measures the actual mass or concentration of the active, unbound Protein S molecule in the blood, expressed as a percentage of normal pooled plasma.

Understanding a Protein S Antigen (Free) Report

The Protein S Antigen (Free) test measures the amount of functional Protein S circulating freely in your blood. Protein S is essential for regulating blood clotting, and abnormal levels can indicate a higher risk of clot formation or inherited clotting disorders.
Here’s how to interpret the results: