antithrombin III

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Related to antithrombin III: antithrombin III test, protein C


any naturally occurring or therapeutically administered substance that neutralizes the action of thrombin and thus limits or restricts blood coagulation.
antithrombin I fibrin, referring to the capacity of fibrin to adsorb thrombin and thus neutralize it.
antithrombin III a naturally occurring inhibitor of blood coagulation; it is an α2-globulin member of the serpin group, synthesized in the liver and found in the plasma and various extravascular sites. It inactivates thrombin as well as certain coagulation factors and kallikrein. Inherited deficiency of the protein, an autosomal dominant disorder, is associated with recurrent deep vein thrombosis and pulmonary emboli. Complications from the disorder are prevented and, in conjunction with heparin, treated with a preparation of antithrombin III from pooled human plasma, administered intravenously.

an·ti·throm·bin III

a plasma α2-globulin process that inhibits thrombin and has anticoagulant activities. Deficiency [MIM*107300] is commonly inherited as an autosomal dominant trait, caused by mutation in antithrombin III gene (AT3) or chromosome 1q; this is one of the few known mendelizing disorders from which thrombotic disease occurs.


A gene on chromosome 1q23-q25.1 that encodes antithrombin III, a member of the serine protease inhibitor (serpin) family that rapidly inhibits thrombin, as well as other activated serine proteases of the coagulation system, and regulates the coagulation cascade.

Molecular pathology
SERPINC1 mutations cause antithrombin-III deficiency.

antithrombin III

Hematology A 58 kD α2-glycoprotein with a single polypeptide chain that inactivates serine proteases–thrombin and other coagulation proteins including factor Xa, IXa, kallikrein and others by an irreversible heparin-dependent reaction Function AT III dissolves blood clots that normally form within the circulation; heparin's anticoagulant activity hinges on activation of AT-III; AT-III-deficient individuals do not benefit from heparin therapy; ↓ AT-III may be a congenital AD condition, or acquired, occurring in DIC–due to 'consumption' or in liver disease–due to ↓ AT-III production, resulting in an ↑ risk of coagulation; AT III is ↓ in congenital deficiency, liver transplant, DIC, nephrotic syndrome, cirrhosis, chonic liver disease, carcinoma, mid-menstrual cycle; AT III is defective in 0.14% to 0.5% of the general population. See Hereditary thrombophilia, Recombinant human antithrombin III.
References in periodicals archive ?
Hypercoagulability can be due to many factors, including decreased levels of Antithrombin III (ATIII).
Differential diagnosis of DIC included microangiopathic pathologies like infectious reasons (purpura fulminans), soft tissue injury due to trauma, snake or insect venom, severe thrombotic, thrombocytopenic purpura and hemolytic uremic syndrome and hereditary thrombotic abnormalities like antithrombin III deficiency, and heterozygous PC and PS deficiency.
2]-antiplasmin, and antithrombin III did not reveal any immunoreactive peaks (data not shown).
To treat shock, dopamine and fresh frozen plasma were administered with antithrombin III and antibiotic therapy (initially, pentocillin 2 g/day + panipenem/betamipron 1 g/day + amikacin 100 mg/day, and subsequently, panipenem/betamipron 1 g/day + vancomycin 1 g/day).
Scientists say the first cloned transgenic goat produces human antithrombin III (rhATIII) in its milk.
Other recent Genzyme Transgenics patents include the right to produce antibodies at commercial levels in the milk of transgenic animals and to produce recombinant human antithrombin III in the milk of goats.
Genzyme Transgenics' main product, developed on the East Coast, is antithrombin III, a plasma protein that helps to regulate blood clotting.
The furthest along, he estimates, is a milk-produced blood-clotting agent, antithrombin III, developed by Genzyme Transgenics Corp.
Primary hypercoagulable states involve specific abnormalities of hemostasis and include antithrombin III deficiency, protein C deficiency, protein S deficiency, lupus anticoagulant, disorders of fibrinolytic system (eg, disorders of tissue plasminogen activator, abnormal plasminogen and hypoplasminogenemia), dysfibrinogenemia factor XII deficiency, and anticardiolipin antibody syndrome.
Electronic auction: auction in electronic form for the right to conclude a contract for the supply of the drug antithrombin iii.