Protein S Activity
Protein S is a vitamin K-dependent plasma protein that functions as a cofactor for Activated Protein C in the regulation of blood clotting. Together, Protein C and Protein S form a natural anticoagulant pathway that prevents excessive thrombin generation and limits abnormal clot formation. Adequate Protein S activity is essential for maintaining haemostatic balance. When levels are reduced or functional activity is impaired, the risk of thrombosis may increase.
- Price: £106
- Code: PS1
- TAT: 8 Working Days
- Sample Type: Blood
Clinical Significance
Protein S deficiency may be inherited or acquired and is recognised as a cause of thrombophilia. Individuals with inherited deficiency may present with deep vein thrombosis, pulmonary embolism, or recurrent clotting episodes, sometimes at a young age. Acquired reductions may occur in pregnancy, liver disease, vitamin K deficiency, severe infection, autoimmune disorders, or during anticoagulant therapy. Because Protein S circulates in both free and bound forms, functional activity measurement is often preferred for accurate clinical assessment. This test is typically included in comprehensive thrombophilia screening when investigating unexplained venous thromboembolism or recurrent pregnancy loss.
Who Might Benefit From This Test?
This test may be appropriate for individuals with unexplained clotting events, strong family history of thrombosis, or recurrent miscarriage. It may also be requested when abnormal coagulation profiles require further clarification. Clinicians frequently assess Protein S activity alongside Protein C and antithrombin to obtain a complete understanding of anticoagulant pathway integrity.
Sample Collection
A blood sample is obtained by a trained healthcare professional. The procedure is quick and minimally invasive. Samples are analysed in specialist laboratories to determine functional Protein S activity levels.
Understanding Your Results
Results are interpreted within the context of clinical history, additional thrombophilia markers, and timing of testing. Reduced activity may indicate inherited deficiency or an acquired condition affecting clot regulation. Because levels can fluctuate during pregnancy or acute illness, repeat testing may occasionally be recommended. Careful interpretation ensures appropriate risk assessment and management planning.
FAQs
When will I receive my results?
Results are usually available within the stated turnaround time.
Should I discuss my results with a doctor?
Yes, results should always be reviewed with a qualified healthcare professional.
Why Choose Marylebone Diagnostic Centre?
Marylebone Diagnostic Centre provides comprehensive coagulation and thrombophilia testing in a professional and discreet setting. Our experienced clinical team ensures accurate sample processing and collaboration with accredited laboratories. With a turnaround time of 8 days, this test supports detailed evaluation of clotting balance and vascular risk.
Book Now
Book the Protein S Activity (PS1) test today to support thorough assessment of your clotting regulation system.
