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Clotting status
PT
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Prothrombin is a plasma protein produced by the liver. A prothrombin time test measures how long it takes for the blood to clot. Clotting is caused by a series of clotting factors activating each other, including the conversion of prothrombin to thrombin.
APTT
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APTT, or Activated Partial Thromboplastin Time measures the speed at which blood clots in the body are formed, through a route known as the intrinsic pathway.
INR
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The international normalised ratio (INR) is a laboratory measurement of how long it takes for blood to form a clot. This can be useful to be able to determine the effects of anticoagulants such as warfarin on the clotting system.
dRVVT normal control
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Venom from the Russell's Viper snake causes blood to clot more quickly, whilst antiphospholipid syndrome slows down the speed at which blood clots. This test compares the time taken for a patient's blood sample to clot when it is mixed with Russell's Viper venom, and compares it to the speed for a control blood sample to clot .By dividing the time taken for the patient's sample to clot by the time taken for the control sample to clot a ratio is created, this helps to correct for the variability that can happen in reference ranges across laboratories. People who have antiphospholipid syndrome will clot more slowly, so the DRVVT ratio will be increased. DRVVT control is the time taken for the control sample to clot.
dRVVT ratio
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Venom from the Russell's Viper snake causes blood to clot more quickly, whilst antiphospholipid syndrome slows down the speed at which blood clots. This test compares the time taken for a patient's blood sample to clot when it is mixed with Russell's Viper venom, and compares it to the speed for a control blood sample to clot.By dividing the time taken for the patient's sample to clot by the time taken for the control sample to clot a ratio is created, this helps to correct for the variability that can happen in reference ranges across laboratories. People who have antiphospholipid syndrome will clot more slowly, so the DRVVT ratio will be increased.
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