FACTOR XI (ROSENTHAL) FUNCTIONAL ACTIVITY

The FACTOR XI (ROSENTHAL) FUNCTIONAL ACTIVITY test is a specialized coagulation assay used to measure the level and function of Factor XI, an important protein in the intrinsic pathway of blood clotting.

Factor XI plays a role in stabilizing clot formation by activating downstream clotting factors. A deficiency or dysfunction of Factor XI can lead to a rare bleeding disorder known as Hemophilia C (Rosenthal syndrome).

Unlike Hemophilia A and B, Hemophilia C is usually milder but can still cause excessive bleeding after surgery, trauma, or dental procedures. This test helps diagnose Factor XI deficiency and evaluate clotting efficiency.

Benefits of the Test

• Diagnoses Hemophilia C (Factor XI deficiency)
• Evaluates unexplained bleeding disorders
• Assesses intrinsic coagulation pathway function
• Helps pre-surgical bleeding risk evaluation
• Supports hematology diagnosis of rare clotting disorders
• Guides clinical management in bleeding-prone patients

Why Doctors Recommend This Test

Doctors recommend the Factor XI activity test when patients experience abnormal bleeding despite normal routine coagulation tests or when there is a suspected inherited bleeding disorder. It is especially important in patients with a family history of bleeding tendencies or those undergoing surgical procedures.

This test helps identify hidden coagulation defects that may not appear in basic screening tests like PT or APTT alone.

Preparation Before Test

• No fasting required
• Inform doctor about anticoagulant medications
• Share family history of bleeding disorders
• Do not stop prescribed medications without medical advice
• Blood sample is collected under standard laboratory conditions

Normal Reporting Time

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

Who Should Take This Test

• Patients with unexplained bleeding episodes
• Suspected Hemophilia C cases
• Individuals with prolonged bleeding after surgery or trauma
• Patients with abnormal APTT results
• Pre-surgical coagulation screening patients
• Individuals with family history of bleeding disorders