An Overview of Coagulation Factor

Coagulation factors are various protein components involved in the blood coagulation process. Its physiological role is to activate when blood vessels bleed, stick to platelets and fill the leaks on the blood vessels. This process is called coagulation. The entire coagulation process can be roughly divided into two phases, activation of prothrombin and formation of gelatinous fibrin. They are partly produced by the liver. Can be inhibited by coumarin. For the uniform naming, the World Health Organization is numbered in Roman numerals according to the order in which it was discovered.


Related diseases


Hemophilia is a group of hereditary bleeding disorders that cause severe coagulopathy in patients due to the lack of certain blood clotting factors in the blood. Both men and women can develop the disease, but most of the patients are male. Including hemophilia A (A), hemophilia B (B) and factor XI deficiency (formerly known as hemophilia C). The first two are sexually linked recessive inheritance, and the latter are autosomal incomplete recessive inheritance. Hemophilia is most common in congenital bleeding disorders, and bleeding is the main clinical manifestation of the disease. Treatments include topical hemostasis, alternative therapies, and the like. The emerging therapies in the latter include recombinant human clotting factor therapy, which has a tendency to become popular in the future because of its lack of artificial contamination and high safety.


Clinical application


PT extension

It is generally believed that PT elongation represents that the activity of coagulation factors II, V, VII, X is lower than that of normal or anticoagulant substances. Liver function is mildly impaired, PT is still normal, and it is only prolonged when liver parenchymal cells are severely damaged. It is not enough to judge the abnormal blood coagulation function and the degree of hepatocyte injury in patients with liver disease by PT. For example, it may be more valuable to measure the activity of coagulation factor at the same time.


Liver disease and coagulation factor II

Most studies suggest that patients with mild hepatitis and chronic hepatitis have normal or mild decline in coagulation factor II activity; patients with moderate, severe, and cirrhosis of chronic hepatitis have significantly decreased levels of coagulation factor II activity, indicating a reduction in hepatocytes. The degree of damage is closely related. Some studies have suggested that protein-II induced by vitamin Kabsence (PIVKA-II) can be used for the diagnosis of primary liver cancer. Some AFP-negative primary liver cancer patients are positive for PIVKA-II, and some studies have considered PIVKA for small liver cancer patients. The positive rate of -II is higher than that of AFP. It also contributes to the changes of the condition and efficacy of primary liver cancer. AFP and PIVKA-II should be combined in clinical examination.


Coagulation factor V

Studies have shown that clotting factor V activity is reduced in liver function decompensation or severe liver disease, so it is considered to be a good indicator to judge the prognosis of patients with liver disease. Izumi and other studies have shown that acetaminophen-induced fulminant hepatic failure requiring liver transplantation has a positive predictive value of 0.49 for death with factor V activity <20% and 0.57 for <10% for <10%; In patients with fulminant hepatic failure requiring liver transplantation, the positive predictive value for death when coagulation factor V activity is <20% is 0.85, and 1.00 is <10%. Therefore, it is considered that coagulation factor V activity is judged by non-acetaminophen induction. The best predictor of prognosis in patients with fulminant hepatic failure. Zou Zhengsheng and other studies believe that the level of coagulation factor V is more specific than PTA to reflect the prognosis of patients with severe hepatitis. The combination of the two may help to diagnose severe hepatitis earlier and more accurately, and pointed out that the detection of severe hepatitis factor V should be strengthened and the factor V should be emphasized. As a primary screening index for liver transplantation in patients with liver failure. In addition to its prognosis, clotting factor V activity is closely related to the formation of thrombus and can be used as a predictor of portal vein thrombosis.


Coagulation factor VII

Coagulation factor VII has the shortest half-life (4-6 h) and low plasma content (0.5-2 mg/L), so it can be used as an early diagnostic indicator for protein synthesis decline in patients with liver disease. Rodriguez-Inigo et al. detected a negative correlation between the expression of factor VII and the grade of liver fibrosis in patients with chronic liver disease by in situ hybridization of liver biopsy, which can be used as an indicator to predict the degree of fibrosis. Coagulation factor VII activity is also closely related to prognosis. For example, Violi et al. believe that 93% of patients with cirrhosis with factor VII activity <34% die within 10 months of follow-up, so it is considered to be an early prediction of the prognosis of patients with cirrhosis. Indicators to better identify liver transplant candidates. Coagulation factor VII activity can be significantly decreased in patients with cirrhosis, factor VII deficiency can lead to changes in platelet activity, combined with reduced platelet count to prolong bleeding time, therefore, in patients with cirrhosis with invasive diagnosis and treatment, factor VII activity should also be used. Perform an assessment of the risk of bleeding, not just the platelet count. In addition to diagnosis, recombinant factor VII can effectively correct coagulation abnormalities in patients with liver disease, which is conducive to the initiation of invasive examination.


Coagulation factor VIII

Coagulation factor 8 is not only produced by hepatocytes, but also by sinusoidal endothelial cells and Kupffer cells, and other tissues such as the kidneys can also be produced. When hepatocyte synthesis declines, sinusoidal endothelial cells and Kupffer cells still maintain the synthesis of factor 8; liver clearance is reduced, endotoxin and immune factors stimulate its synthesis and release. Fan Wei’s factor is mainly synthesized by extrahepatic. Patients with cirrhosis may have increased release due to endotoxemia and dysfunction of vascular endothelial cells; vWF degrading proteases reduce their decomposition and increase plasma levels. Coagulation factor 8 activity and vWF were significantly elevated in most patients with viral hepatitis. However, patients with liver disease and DIC, due to the large consumption of coagulation factors, reduce the activity level of factor 8 antibody, so China’s activity of factor 8 is less than normal 50% as one of the necessary conditions for the diagnosis of liver disease combined with DIC.


Various components involved in the blood coagulation process; most of them are sugar-containing serine proteases. The entire coagulation process can be roughly divided into two phases, activation of prothrombin and formation of gelatinous fibrin.