Factor VII Test

Factor VII is also known as proconvertin. It is a protein that causes the blood to coagulate in the blood cascade. It is also an enzyme of the class serine protease. Along with the tissue factor, factor VII plays a vital role in initiating the blood coagulation process. Tissue factor remains outside the blood vessels and isn’t exposed with the blood. In case of an injury, Tissue factor comes in contact with the blood mixed with Factor VII. At this moment, Factor VII is converted into its activated form, viz., Factor VIIa by different proteases. Factor VIIa and Tissue factor together then initiate the process of coagulation in order to heal the injury. Deficiency of Factor VII or congenital proconvertin deficiency is a rare and inherited recessive disease. It is a haemophilia like bleeding disorder in which the blood fails to form clot during minor or severe injuries. Normal adult have 65-180 per cent of Factor VII in his blood.

Blood sample needs to be collected in order to test for the Factor VII Blood is collected in a blue-top vessel containing 3.2 per cent buffered sodium nitrate. In order to maintain the proper blood to anticoagulant ratio, the vessel must be completely filled and the blood and anticoagulant mixture needs to be mixed properly immediately after the sample is taken to ensure that both are mixed together properly. The sample must be kept frozen to avoid the deviation of the result.

The test is done to examine the congenital deficiency of the coagulation factor VII The test is also performed to check the acquired deficiencies which are associated with the liver diseases, vitamin K deficiency and oral anticoagulation therapy To investigate the prolonged prothrombin time To know the reason behind delayed or no formation of the clot. At times, disease of liver, vitamin K deficiency and warfarin intake may also be a cause for the decreased concentration of the Factor VII.

Spin the sample collected in the blue-top vessel for at least 5 minutes in the stat spin centrifuge. Separate the plasma from the blood and transfer the remaining part to a 4 mL BCS sample cups. Again, spin the remaining part of the plasma for at least 5 minutes in the Stat Centrifuge Spin. Let 20mcL of the sample rest in the tube and transfer the rest into a new tube for the analysis.