Overview: Von Willebrand Factor Antigen TestIntroduction: The Von Willebrand Factor Antigen Test measures vWF antigen to diagnose von Willebrand disease, causing excessive bleeding. Aligned with 2023 ASH guidelines, it uses coagulation methods for high specificity, supporting coagulation screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in coagulation for patients with suspected von Willebrand disease.
Other Names: vWF Antigen Assay, Von Willebrand Factor Test.
FDA Status: Laboratory-developed test (LDT), meeting coagulation standards for diagnostic accuracy.
Historical Milestone: vWF antigen testing began in the 1970s with bleeding disorder research. Coagulation methods improved in the 2000s, enhancing diagnostic precision.
Purpose: Measures vWF antigen to diagnose von Willebrand disease, guides treatment, and evaluates patients with excessive bleeding.
Test Parameters: 1. vWF Antigen Level
Pretest Condition: No fasting required. Collect citrated plasma. Report history of bleeding or coagulation disorders.
Specimen: Citrated Plasma (NaCit, 2-4 mL). Transport in a biohazard container.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 24 hours
Sample Stability at Frozen: Not frozen
Medical History: Document excessive bleeding, bruising, or history of coagulation disorders. Include current medications, especially anticoagulants.
Consent: Written consent required, detailing the tests purpose, von Willebrand disease implications, and risks of sample collection.
Procedural Considerations: Uses enzyme-linked immunosorbent assay (ELISA) to measure vWF antigen levels. Results are available in 1-2 days, supporting clinical decisions. Performed in laboratories, often for bleeding disorder diagnosis.
Factors Affecting Result Accuracy: Sample hemolysis or improper collection can affect results. Stress or inflammation may elevate vWF levels.
Clinical Significance: Low vWF antigen confirms von Willebrand disease, guiding desmopressin or vWF replacement therapy. Normal levels may require functional vWF tests.
Specialist Consultation: Consult a hematologist for result interpretation and treatment planning.
Additional Supporting Tests: vWF activity, factor VIII, or bleeding time to confirm von Willebrand disease diagnosis.
Test Limitations: Non-specific for disease type; clinical correlation is needed. Sample quality affects sensitivity.
References: ASH Hematology Guidelines, 2023; Blood, Leebeek FW, 2022.
