Coagulation: Difference between revisions
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==Biochemistry== | ==Biochemistry== | ||
The | All coagulation factors are produced in the liver except for von Willebrand's factor.<ref name="pmid10533518">{{cite journal |author=Sallah S, Bobzien W |title=Bleeding problems in patients with liver disease. Ways to manage the many hepatic effects on coagulation |journal=Postgrad Med |volume=106 |issue=4 |pages=187–90, 193–5 |year=1999 |pmid=10533518 |doi=|url=http://www.postgradmed.com/issues/1999/10_01_99/sallah.htm}}</ref> However, Factor VIII levels may be normal in liver disease.<ref name="pmid10533518"/><ref name="pmid1333467">{{cite journal |author=Mammen EF |title=Coagulation abnormalities in liver disease |journal=Hematol. Oncol. Clin. North Am. |volume=6 |issue=6 |pages=1247–57 |year=1992 |pmid=1333467 |doi=}}</ref> The synthesis of coagulation factors II, VII, IX, and X and proteins C and S is dependent on vitamin K.<ref name="pmid1333467">{{cite journal |author=Mammen EF |title=Coagulation abnormalities in liver disease |journal=Hematol. Oncol. Clin. North Am. |volume=6 |issue=6 |pages=1247–57 |year=1992 |pmid=1333467 |doi=}}</ref> | ||
===Intrinsic pathway=== | ===Intrinsic pathway=== | ||
Revision as of 00:50, 13 January 2008
Coagulation is "the process of the interaction of blood coagulation factors that results in an insoluble fibrin clot."[1]
Biochemistry
All coagulation factors are produced in the liver except for von Willebrand's factor.[2] However, Factor VIII levels may be normal in liver disease.[2][3] The synthesis of coagulation factors II, VII, IX, and X and proteins C and S is dependent on vitamin K.[3]
Intrinsic pathway
The intrinsic pathway uses Factors VIII, IX, XI, and XII. The partial thromboplastin time measures the function of the intrinsic pathway and the common pathway.
Extrinsic pathway
The extrinsic pathway uses Factors VII and X. The prothrombin time measures the function of the extrinsic pathway and the common pathway.
Final common pathway
The final common pathway used factors II (prothrombin) and I (fibrinogen).
Disorders of coagulation
Blood coagulation disorders are "hemorrhagic and thrombotic disorders that occur as a consequence of abnormalities in blood coagulation due to a variety of factors such as coagulation protein disorders; blood platelet disorders; blood protein disorders or nutritional conditions."[4]
Factor I deficiency
Deficiency of Factor I (fibrinogen) may be inherited (afibrinogenemia) or acquired.
Factor II deficiency
Deficiency of Factor II (prothrombin) leads to hypoprothrombinemia. The defiency may be acquired in due to prothrombin antibodies.[5]
Factor V deficiency
Factor V deficiency is a "(known as proaccelerin or accelerator globulin or labile factor) leading to a rare hemorrhagic tendency known as Owren's disease or parahemophilia. It varies greatly in severity. Factor V deficiency is an autosomal recessive trait."[6]
Factor X deficiency
Factor X deficiency is a "blood coagulation disorder usually inherited as an autosomal recessive trait, though it can be acquired. It is characterized by defective activity in both the intrinsic and extrinsic pathways, impaired thromboplastin time, and impaired prothrombin consumption."[7]
References
- ↑ Anonymous. Blood coagulation. National Library of Medicine. Retrieved on 2008-01-10.
- ↑ 2.0 2.1 Sallah S, Bobzien W (1999). "Bleeding problems in patients with liver disease. Ways to manage the many hepatic effects on coagulation". Postgrad Med 106 (4): 187–90, 193–5. PMID 10533518. [e]
- ↑ 3.0 3.1 Mammen EF (1992). "Coagulation abnormalities in liver disease". Hematol. Oncol. Clin. North Am. 6 (6): 1247–57. PMID 1333467. [e]
- ↑ Anonymous. Blood Coagulation Disorders. National Library of Medicine.
- ↑ Bajaj SP, Rapaport SI, Fierer DS, Herbst KD, Schwartz DB (1983). "A mechanism for the hypoprothrombinemia of the acquired hypoprothrombinemia-lupus anticoagulant syndrome". Blood 61 (4): 684–92. PMID 6403077. [e]
- ↑ Anonymous. Factor V Deficiency. National Library of Medicine.
- ↑ Anonymous. Factor X Deficiency. National Library of Medicine.