Factor X

Factor X

We remind you that independent interpretation of the results is unacceptable, the information provided below is for reference purposes only.

Factor X, also known as Stuart-Prower factor, is a key component of the coagulation cascade, playing a crucial role in the formation of blood clots. It is a serine protease enzyme that helps convert prothrombin (Factor II) into thrombin (Factor IIa), which is essential for the final step of the clotting process.

Structure and Function of Factor X

Factor X is synthesized in the liver as an inactive zymogen (an inactive precursor of an enzyme). It circulates in the bloodstream and becomes activated when the coagulation cascade is initiated. The activation process involves the removal of a small peptide from the zymogen, resulting in the active form of Factor X, known as Factor Xa.

Factor Xa, along with its cofactor Factor Va, forms the prothrombinase complex, which catalyzes the conversion of prothrombin to thrombin. Thrombin, in turn, facilitates the formation of fibrin clots, ultimately leading to the cessation of bleeding.

The Role of Factor X

Factor X plays a crucial role in the blood coagulation process. It is a serine protease enzyme that acts as a critical link between the intrinsic and extrinsic pathways of the coagulation cascade. Factor X is activated by the intrinsic tenase complex (activated factors VIII and IX) or the extrinsic tenase complex (activated factor VII and tissue factor).

Indications for Factor X Testing

Factor X testing is indicated in the evaluation of bleeding disorders and coagulation abnormalities. It may be ordered in the following circumstances:

• Suspected factor X deficiency: Factor X deficiency is a rare inherited bleeding disorder characterized by a prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT).
• Monitoring of anticoagulant therapy: Factor X levels may be monitored in patients receiving certain anticoagulants, such as heparin or direct factor Xa inhibitors.
• Evaluation of liver disease: Since factor X is synthesized in the liver, its levels may be reduced in liver disorders, such as cirrhosis or hepatitis.
• Investigation of unexplained bleeding or clotting disorders: Factor X testing may be part of a comprehensive coagulation workup in cases of unexplained bleeding or clotting disorders.

Preparation for the Factor X Analysis Procedure

The procedure for blood collection to determine Factor X levels is relatively simple and does not require special preparation measures. However, there are several recommendations that should be considered:

• Dietary regimen: In most cases, the blood test for Factor X can be taken either fasting or after eating. However, in some situations (e.g., during a comprehensive biochemical blood analysis), an 8-12 hour fast before blood collection may be required.
• Avoiding physical exertion: It is advisable to avoid intense physical activity on the day before the test, as it may affect the results.
• Abstaining from alcohol and smoking: It is recommended to refrain from alcohol consumption and smoking a day before the test, as they can influence Factor X levels and other blood parameters.
• Maintaining hydration: Adequate hydration is essential for facilitating the blood collection procedure. Insufficient fluid intake can make the venipuncture procedure more challenging.
• Informing healthcare providers about medications: Some medications can affect Factor X levels and other blood parameters. Therefore, it is crucial to inform the healthcare provider about all medications being taken.

The Analysis Procedure

Blood collection for the Factor X analysis is typically performed from a vein in the antecubital fossa (inner elbow area). The procedure takes a few minutes and is carried out by a healthcare professional. After venipuncture, minor bleeding or bruising may occur, which usually resolves on its own within a few days.

About Factor X Assay

The factor X assay is a coagulation test used to measure the activity level of factor X, which is one of the clotting factors involved in the blood coagulation process. It is often performed as part of a comprehensive evaluation of bleeding disorders or to monitor the effectiveness of anticoagulant therapy.

The assay typically involves mixing the patient's plasma sample with a reagent that initiates the coagulation cascade. The time it takes for the sample to clot is then measured, and this clotting time is inversely proportional to the concentration of factor X present in the sample.

Factor X plays a crucial role in the coagulation cascade, acting as a link between the intrinsic and extrinsic pathways. Measuring its activity level can provide valuable information about the patient's overall coagulation status and aid in the diagnosis and management of various bleeding disorders or thrombotic conditions.

Sources:

https://ufhealth.org/conditions-and-treatments/factor-x-assay
https://www.mountsinai.org/health-library/tests/factor-x-assay
https://rarediseases.org/rare-diseases/factor-x-deficiency/
https://www.ucsfhealth.org/medical-tests/factor-x-assay
https://www.labcorp.com/tests/086306/factor-x-activity
https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=factor_x
https://emedicine.medscape.com/article/2085340-overview
https://www.healthline.com/health/factor-x-deficiency

IMPORTANT!

It is crucial to remember that the information provided in this section is not intended for self-diagnosis or self-treatment. If you experience any symptoms or a worsening of your condition, it is essential to consult a healthcare professional for proper diagnostic testing and treatment. Only a qualified specialist can make an accurate diagnosis and determine the appropriate treatment. To obtain the most accurate and consistent evaluation of your test results, it is recommended to have them performed at the same laboratory. Different laboratories may use varying methods and units of measurement for similar tests.