Antiphospholipid antibodies represent a family of immunoglobulins which recognize phospholipids, alone or bound to plasma protein cofactor(s), or the cofactors themselves. A variety of proteins have been implicated including: Prothrombin, β2-Glycoprotein I, Protein S and Annexin V.
These antibodies are found to be associated with a variety of thrombotic complications involving both arterial and venous sites, as well as recurrent miscarriages and thrombo-
cytopenia. The pathophysiologic mechanisms of this antiphospholipid syndrome (APS) have not yet been identified.
Annexin V, also known as placental anticoagulant protein I (PAP I), not only belongs to a family of proteins that bind to phospholipids in a calcium dependent manner, but is also a potent vascular anticoagulant protein.Annexin V is necessary to maintain placental integrity and may have a thromboregulatory effect at the materno-fetal interface, as shown in a murine model.
It has been suggested, that interference of anti-Annexin V antibodies with the Annexin V shield on the placental villi leads to the exposure of anionic procoagulant phospholipids. Anionic pro-coagulant phospholipids are known to enhance blood coagulation processes in the placental vasculature, and may be an important contributory factor of thrombosis and recurrent loss of pregnancy in the APS. Anti-Annexin V antibodies are not only highly specific for APS, elevated levels of antibodies can also be detected in patients with systemic lupus diseases (SLE). Further, it has been suggested that anti-Annexin V autoantibodies may influence in the clinical course of rheumatoid arthritis, and a significantly high frequency of arterial or venous thrombosis is found in patients with anti-annexin V antibodies.
They have also been discussed to be associated with recurrent miscarriages in SLE patients
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| Tests |
12 x 8 Tests
(break away modules)
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| Calculation |
quantitative |
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| Range |
0 – 100 U/ml (6 standards)
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| Cut-off |
5 U/ml |
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| Sensitivity |
1 U/ml |
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| Calibration |
arbitrary
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| Substrate |
TMB / 450 nm
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Instruction for Use: ORG 643-0508-01-gb.pdf
Material-Safety-Datasheet: ORG 643.pdf