What is protein S antigen?
Protein S is a vitamin K-dependent glycoprotein present in platelets and synthesized within the liver and endothelial cells. Protein S works as part of the natural anticoagulant system by acting as a cofactor to activated protein C (APC) in the proteolytic inactivation of procoagulant factors Va and VIIIa.
What does protein S activity mean?
Normal activity and level of protein C and protein S usually indicate adequate clotting regulation. Low protein C or protein S level or activity indicates blood clotting is not sufficiently regulated and there is an increased risk of developing a clot that blocks the flow of blood in the veins.
What is the difference between protein C and S?
Congenital C and S proteins are natural substances in the blood that help prevent blood clots. Protein C deficiency occurs in approximately 1 of every 200 to 500 people, whereas protein S deficiency occurs in approximately 1 of every 500 individuals.1,2 Deficiency may be determined from a blood sample.
What is normal protein S activity?
These percentage values should usually fall between 60 and 150. There might be slight differences among testing facilities. High levels of protein S are not typically cause for concern, whereas low levels may increase your risk of blood clots.
What does low protein S activity mean?
When you have too little protein S, it’s harder for your body to control the coagulation pathway. This can result in excessive clotting. Having this deficiency puts you at risk for a blood clot in your leg or arm veins that’s known as a deep vein thrombosis (DVT).
How does protein C and S work?
Protein C and protein S work together to prevent your blood from clotting too much. Normally, your body makes blood clots to stop bleeding after a cut or other injury. If you don’t have enough protein C (protein C deficiency) or enough protein S (protein S deficiency), your blood can clot more than you need it to.
Does protein S decrease in pregnancy?
Protein S is a cofactor of protein C which lowers the activated factors VIII and V. Pregnancy reduces the level of protein S to 40-50% of normal levels but it is not clear whether the lowered protein S levels increase the risk of developing thrombo-embolism during pregnancy.
What is the function of protein C and protein S?
Does warfarin inhibit protein C and S?
Warfarin inhibits the body’s own production of protein C and protein S. Therefore, initial treatment with warfarin alone in people with protein C or protein S deficiency may temporarily make clotting worse or precipitate a new clot or a severe skin rash known as skin necrosis.
Is protein S deficiency a disability?
The SSA usually accepts a blood clotting disorder diagnosis based on the assessment of a patient’s plasma clotting-factor proteins (factors) and platelets. The type of hypercoagulation disorder (such as protein C or protein S deficiency) will be used to determine your disability rating.
Can I donate blood if I have protein S deficiency?
If you have an inherited condition that makes it more likely that you would have a DVT, such as Factor V Leiden or Protein C or Protein S deficiency, and you have not had a DVT, you can give blood. However, if these conditions caused even one DVT, you cannot give blood.
Where is protein S produced?
the liver
Protein S is made chiefly by cells in the liver. The protein circulates in the bloodstream in two forms; it is either attached (bound) to a specific protein or occurs by itself in a free form.
