Coagulation Factors
| Number and/or name | Function | Associated genetic disorders |
|---|---|---|
| I (fibrinogen) | Forms clot (fibrin) | Congenital afibrinogenemia, Familial renal amyloidosis |
| II (prothrombin) | Its active form (IIa) activates I, V, VII, VIII, XI, XIII, protein C, platelets | Prothrombin G20210A, Thrombophilia |
| III Tissue factor | Co-factor of VIIa (formerly known as factor III) | |
| IV Calcium | Required for coagulation factors to bind to phospholipid (formerly known as factor IV) | |
| V (proaccelerin, labile factor) | Co-factor of X with which it forms the prothrombinase complex | Activated protein C resistance |
| VI | Unassigned – old name of Factor Va | |
| VII (stable factor, proconvertin) | Activates IX, X | congenital proconvertin/factor VII deficiency |
| VIII (Antihemophilic factor A) | Co-factor of IX with which it forms the tenase complex | Haemophilia A |
| IX (Antihemophilic factor B or Christmas factor) | Activates X: forms tenase complex with factor VIII | Haemophilia B |
| X (Stuart-Prower factor) | Activates II: forms prothrombinase complex with factor V | Congenital Factor X deficiency |
| XI (plasma thromboplastin antecedent) | Activates IX | Haemophilia C |
| XII (Hageman factor) | Activates factor XI, VII and prekallikrein | Hereditary angioedema type III |
| XIII (fibrin-stabilizing factor) | Crosslinks fibrin | Congenital Factor XIIIa/b deficiency |
| von Willebrand factor | Binds to VIII, mediates platelet adhesion | von Willebrand disease |
| prekallikrein (Fletcher factor) | Activates XII and prekallikrein; cleaves HMWK | Prekallikrein/Fletcher Factor deficiency |
| high-molecular-weight kininogen (HMWK) (Fitzgerald factor) | Supports reciprocal activation of XII, XI, and prekallikrein | Kininogen deficiency |
| fibronectin | Mediates cell adhesion | Glomerulopathy with fibronectin deposits |
| antithrombin III | Inhibits IIa, Xa, and other proteases | Antithrombin III deficiency |
| heparin cofactor II | Inhibits IIa, cofactor for heparin and dermatan sulfate ("minor antithrombin") | Heparin cofactor II deficiency |
| protein C | Inactivates Va and VIIIa | Protein C deficiency |
| protein S | Cofactor for activated protein C (APC, inactive when bound to C4b-binding protein) | Protein S deficiency |
| protein Z | Mediates thrombin adhesion to phospholipids and stimulates degradation of factor X by ZPI | Protein Z deficiency |
| Protein Z-related protease inhibitor (ZPI) | Degrades factors X (in presence of protein Z) and XI (independently) | |
| plasminogen | Converts to plasmin, lyses fibrin and other proteins | Plasminogen deficiency, type I (ligneous conjunctivitis) |
| alpha 2-antiplasmin | Inhibits plasmin | Antiplasmin deficiency |
| tissue plasminogen activator (tPA) | Activates plasminogen | Familial hyperfibrinolysis and thrombophilia |
| urokinase | Activates plasminogen | Quebec platelet disorder |
| plasminogen activator inhibitor-1 (PAI1) | Inactivates tPA & urokinase (endothelial PAI) | Plasminogen activator inhibitor-1 deficiency |
| plasminogen activator inhibitor-2 (PAI2) | Inactivates tPA & urokinase (placental PAI) | |
| cancer procoagulant | Pathological factor X activator linked to thrombosis in cancer |
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Famous quotes containing the word factors:
“The goal of every culture is to decay through over-civilization; the factors of decadence,—luxury, scepticism, weariness and superstition,—are constant. The civilization of one epoch becomes the manure of the next.”
—Cyril Connolly (1903–1974)