FACTOR XII (HAGEMAN) ACTIVITY

The FACTOR XII (HAGEMAN) ACTIVITY test is a specialized coagulation assay used to measure the functional activity of Factor XII, also known as the Hageman factor. This protein is an important component of the intrinsic pathway of the blood clotting system and plays a role in initiating the coagulation cascade when blood comes into contact with damaged surfaces.

Interestingly, Factor XII deficiency usually causes prolonged laboratory clotting times (especially APTT) but is often not associated with significant bleeding symptoms, making it a unique clotting factor disorder.

This test is mainly used to evaluate abnormal coagulation screening results and to investigate intrinsic pathway abnormalities.

Benefits of the Test

• Identifies Factor XII deficiency
• Evaluates abnormal APTT results
• Helps assess intrinsic coagulation pathway function
• Supports hematology diagnostic workup
• Differentiates causes of prolonged clotting time
• Useful in pre-surgical coagulation evaluation

Why Doctors Recommend This Test

Doctors recommend the Factor XII activity test when routine coagulation screening (especially APTT) shows unexplained prolongation without a clear bleeding history. It helps determine whether Factor XII deficiency is responsible for abnormal lab results.

It is also used in hematology workups to rule out intrinsic pathway defects and to better understand coagulation abnormalities before surgical or diagnostic procedures.

Preparation Before Test

• No fasting required
• Inform doctor about anticoagulant medications
• Share history of clotting or bleeding disorders
• Avoid stopping prescribed medications without medical advice
• Standard blood sample collection is used

Normal Reporting Time

Results are typically available within 24 to 48 hours, depending on laboratory processing time.

Who Should Take This Test

• Patients with prolonged APTT results
• Individuals undergoing pre-surgical coagulation screening
• Suspected intrinsic pathway clotting disorders
• Patients with unexplained laboratory abnormalities
• Hematology evaluation cases
• Individuals referred by specialists for coagulation workup