Protein S Antigen (Free)

This test measures the levels of Protein S antigen in your blood. Protein S is an important protein that helps regulate blood clotting. It binds to another protein called Protein C, forming a complex that inhibits clot formation. The measurement of Protein S levels provides valuable information about your risk of developing blood clotting disorders.

• To diagnose and monitor blood clotting disorders, such as Protein S deficiency or abnormalities
• To evaluate the effectiveness of treatment for blood clotting disorders
• To assess the risk of developing thrombosis or excessive blood clotting

Your doctor may recommend this test if you have:

• A personal or family history of blood clotting disorders
• Recurrent miscarriages
• A history of abnormal blood clots
• Plans to undergo treatment for blood clotting disorders, to monitor the effectiveness of the treatment
• Plans to undergo surgery or are on hormonal therapy, as these situations can increase the risk of developing blood clots

The normal range for Protein S levels varies depending on the laboratory but is usually between 60% and 140% of the reference range. Abnormal results can indicate a deficiency or dysfunction of Protein S, which may increase the risk of developing blood clotting disorders. Further evaluation and consultation with your doctor are necessary to determine the significance of abnormal results.

During this test:

• A healthcare professional will draw a blood sample from your vein
• The blood sample will be collected in a special tube containing an anticoagulant
• The sample will be sent to the laboratory for analysis
• You may experience a brief, mild discomfort when the needle is inserted to collect the blood sample

To prepare for this test:

• You may need to fast for at least 8 hours before the test
• Inform your doctor about any medications, supplements, or herbal remedies you are taking
• Avoid smoking and strenuous exercise before the test
• Follow any other instructions provided by your doctor regarding specific dietary restrictions or medication adjustments

• Protein C assay: Measures the levels of Protein C, another protein involved in regulating blood clotting
• Genetic testing for inherited thrombophilia: Helps identify genetic mutations that increase the risk of blood clots
• D-dimer test: Detects the presence of a substance released when a blood clot breaks down

Free Protein S Antigen Test or Protein S Test

Deep vein thrombosis (DVT) is a condition where blood clots form within the deep veins, usually in the legs. It can lead to pain, swelling, and potentially life-threatening complications if the clot dislodges and travels to the lungs (pulmonary embolism).