What does protein S do in coagulation?
Protein S helps block the activity of (inactivate) certain proteins that promote the formation of blood clots. Most mutations that cause protein S deficiency change single protein building blocks (amino acids) in protein S, which disrupts its ability to control blood clotting.
What does protein S test for?
Protein S helps control blood clotting. A lack of this protein or problem with the function of this protein may cause blood clots to form in veins. The test is also used to screen relatives of people who are known to have protein S deficiency . Sometimes, this test is done to find the cause of repeated miscarriages .
What is the function of protein S?
Protein S is involved in many cellular activities, including inhibition of the blood coagulation cascade, inhibition of inflammation, clearance of apoptotic bodies, angiogenesis and cell survival. Protein S functions as an anticoagulant by inhibiting FIXa and by serving as a cofactor for APC and TFPI.
What does protein S inactivate?
Protein S serves as a cofactor for APC and enhances its capacity to inactivate factors Va and VIIIa. In addition, protein S may have direct anticoagulant activity by inhibiting prothrombin activation through its capacity to bind anionic phospholipid, factor Va, or factor Xa, components of the prothrombinase complex.
What does it mean if protein S is high?
Elevated protein S levels are not usually associated with medical problems and are not clinically significant. Normal protein C and protein S antigen activity and concentrations usually indicate adequate clotting regulation. A low level of protein S activity can cause excessive or inappropriate blood clotting.
What does high protein S mean?
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.
How is protein C and S deficiency treated?
Blood thinner medications, also known as anticoagulants, can treat protein C deficiency. These medications cut your risk for blood clot formation by preventing blood from clotting in blood vessels. The medication won’t allow the clots to get bigger, and won’t break up clots that have already formed.
How is protein S deficiency treated?
There is not a specific therapy for patients with protein S deficiency. The use of anticoagulant therapy however is highly effective in the treatment and prevention of blood clots in patients with the common type of protein S deficiency (due to inheritance of one abnormal protein S gene).
Ist die Dosisanpassung in der Schwangerschaft entbehrlich?
Dosisanpassung im Verlauf der Schwangerschaft scheint entbehrlich. Mit einer am Körpergewicht orientierten Dalteparin-Dosierung (5.000 Anti-Xa-E. bei 50 kg bis 80 kg) lassen sich in einer kleinen Studie bei der Mehrzahl der Frauen während der gesamten Schwangerschaft prophylaktische Blutspiegel erzielen.
Was sind die Mittel zur Thromboseprophylaxe in der Schwangerschaft?
Mittel der Wahl zur Thromboseprophylaxe in der Schwangerschaft sind Heparine. Sie überschreiten die Plazenta nicht. Schwangerschaft gilt auch bei niedermolekularen Heparinen nicht mehr grundsätzlich als Kontraindikation.
Welche Entwicklungsstörungen sind in der Schwangerschaft zu befürchten?
Entwicklungsstörungen des zentralen Nervensystems können zu jedem Zeitpunkt des Gebrauchs in der Schwangerschaft auftreten. Ursächlich kommen u.a. Blutungen mit nachfolgender Narbenbildung in Betracht. Auch Spontanaborte nehmen unter den Kumarinen zu. Während der Entbindung sind vor allem zerebrale Blutungen beim Kind zu befürchten.