Coagulation factor activity assay (factor VIII:C, IX:C)

Factor VII is a macromolecular complex consisting of von Willebrand Factor (VWF) and Factor VIII coagulation activity (VIII: C). Factor VIII:C acts as a cofactor for Factor IXa and forms a complex (IXa, VIIIa, Ca2+, phospholipid) with the surface of the Ca2+ phospholipid, which activates Factor X. The methods for determining the blood coagulation activities of factors VII and IX are one-stage method and two-stage method. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Reduced in hemophilia. Normal value: Factor VIII:C:78-128 Factor IX:C:68-128 Above normal: Increased in hypercoagulable state and thrombotic disease. negative: Positive: Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. Normal value Factor VIII: C78% to 128%; Factor IX: C68% to 128%. Clinical significance Abnormal result 1. Increase in factor VIII:C or IX:C levels is seen in hypercoagulable states and thrombotic diseases. In particular, venous thrombosis, such as deep vein thrombosis, pulmonary embolism, nephrotic syndrome, oral contraceptives, pregnancy-induced hypertension syndrome, malignant tumors, and liver failure, increased levels of factor VIII:C. 2, factor VIII: C or IX: C level reduction seen in hemophilia A or hemophilia B, according to the degree of reduction is divided into heavy VII: C or IX: C less than 2%, medium 2% ~ 5%, light 5 % to 25%, subclinical type 25% to 45%. Factor VIII:C reduction is also seen in vascular hemophilia, DIC and anti-factor VIII:C antibodies due to acquired blood-borne disease; factor IX:C reduction is also seen in liver disease, vitamin K deficiency, DIC and oral anticoagulation Agents, etc. Low results may be diseases: high results of pulmonary embolism may be diseases: hemophilia precautions Before inspection: 1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. 2. After 8 pm on the day before the medical examination, you should start fasting for 12 hours to avoid affecting the test results. 3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection. 4. It is forbidden to take anticoagulant drugs, such as aspirin, before testing. After inspection: 1. After blood is drawn, local compression is required at the pinhole for 3-5 minutes to stop bleeding. Note: Do not rub, so as not to cause subcutaneous hematoma. 2, the pressing time should be sufficient. There is a difference in clotting time for each person, and some people need a little longer to clotting. Therefore, when the surface of the skin appears to be bleeding, the compression is stopped immediately, and the blood may be infiltrated into the skin due to incomplete hemostasis. Therefore, the compression time is longer to completely stop bleeding. If there is a tendency to bleed, the compression time should be extended. 3, after the blood draw symptoms of fainting such as: dizziness, vertigo, fatigue, etc. should immediately lie down, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved. 4. If there is localized congestion, use a warm towel after 24 hours to promote absorption. Inspection process Take the standard and prepare the standard solution with the effective price (U/mL) of 5, 6, 7, 8, 9, and 10 with physiological saline. Take another 6×10cm plastic test tube, add 450μl of 0.1% fibrinogen solution, preheat for 5min in 37°C water bath, and then take 50μl of each of the above six concentrations of standard solution preheated at 37°C. Add to each of the above test tubes, immediately time and shake well, and record the coagulation time. Each concentration was measured 2 times, averaged, and a standard curve was made. The sample to be tested is diluted with physiological saline to a suitable concentration, 50 μl is taken, and measured in parallel according to the measurement method of the standard curve twice, averaged, and the titer of the sample is calculated according to a standard curve or a regression equation. Not suitable for the crowd People who take aspirin for a long time. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye.