Von Willebrand Factor Antigen vWF Ag Test
Short Name: vWF Ag Test
Also known as: Von Willebrand Factor Antigen, vWF Antigen, vWF Ag, Factor VIII Related Antigen
Von Willebrand Factor Antigen vWF Ag Test test available at DNA Labs India for ₹13,000. Uses Chemiluminescent Immunoassay (CLIA) on 3 mL whole blood in 1 Blue Top (Sodium Citrate) tube samples. Results in If the sample is received by 11 am, the report will be delivered by 6 pm the same day.. Free home collection in 300+ cities across India.
🩺 Medically Reviewed By
Dr Pasupathy Arumugam
Consultant Pathologist · Reg: 21521
Last reviewed: September 7, 2026
Overview
To quantify plasma von Willebrand factor antigen as an aid in diagnosing von Willebrand disease, differentiating it from hemophilia A, and monitoring replacement therapy in patients receiving vWF concentrates.
- Test Code
- 3751
- CPT Code
- 85231
- ICD Code
- D68.0
- Price
- ₹13,000
- Sample Type
- 3 mL whole blood in 1 Blue Top (Sodium Citrate) tube
- Result Time
- If the sample is received by 11 am, the report will be delivered by 6 pm the same day.
- Fasting Required
- No
- Method
- Chemiluminescent Immunoassay (CLIA)
Sample Collection
Overnight fasting is preferred. Inform your doctor about all medications. It is recommended that the patient discontinues Heparin for 1 day and Oral Anticoagulants for 7 days prior to sampling as these drugs may affect test results. Discontinuation should be with prior consent from the treating physician. A duly filled Coagulation Requisition Form (Form 15) is mandatory.
Method: Venipuncture
Laboratory Analysis
A trained phlebotomist will collect 3 mL whole blood from a vein in your arm into a blue-top tube containing sodium citrate. The tube should be mixed gently by inversion to prevent clot formation.
Report Delivery
Pressure will be applied over the puncture site. You may resume normal activities and diet unless advised otherwise. The sample will be processed as per standard coagulation protocol.
Timeline: If the sample is received by 11 am, the report will be delivered by 6 pm the same day.
Patient Instructions
About This Test
Who Should Get This Test
To quantify plasma von Willebrand factor antigen as an aid in diagnosing von Willebrand disease, differentiating it from hemophilia A, and monitoring replacement therapy in patients receiving vWF concentrates.
How to Prepare
- Use a blue-top sodium citrate tube (3 mL).
- Mix the tube thoroughly by inverting 3–4 times.
- Transport the sample to the laboratory within 4 hours.
- If transport is delayed, prepare platelet-poor plasma (PPP) within 1 hour by double centrifugation: 3600 rpm for 15 minutes each time, transfer supernatant to a clean plastic screw-capped vial, and freeze immediately.
- Ship frozen sample. Do not thaw.
- Attach the duly filled Coagulation Requisition Form (Form 15).
Doctor's Notes
Reviewed by Dr Pasupathy Arumugam — MBBS, MD (Pathology) · Reg. No. 21521
"In the evaluation of a suspected bleeding disorder, vWF antigen alone should be interpreted with factor VIII activity and vWF functional assays for accurate diagnosis and subtyping."
Last medically reviewed: September 7, 2026
Test Parameters & Specifications
Sample Stability
- Clotted or visibly haemolysed sample
- Improperly filled citrate tube (under- or over-filled)
- Sample received more than 4 hours after collection without PPP preparation
- Previously frozen whole blood or thawed platelet-poor plasma
- Missing Coagulation Requisition Form (Form 15)
Understanding Your Results
Suggests significant von Willebrand disease; further testing with vWF activity and factor VIII is required to classify.
Borderline low; may be seen in blood group O or mild vWD. Correlate with bleeding symptoms and functional assays.
Normal reference range in most laboratories.
Elevated vWF antigen; can occur in acute phase response, pregnancy, inflammation or liver disease. Does not rule out vWD if functional abnormality is present.
Consult a doctor if you have unexplained bruising or bleeding, prolonged bleeding after cuts, dental work or surgery, heavy menstrual periods, recurrent nosebleeds, or a family history of a bleeding disorder.
Limitations
- ⚠vWF Ag does not assess vWF function; a normal result does not exclude vWD subtypes such as type 2.
- ⚠Plasma vWF levels vary with ABO blood group, age, stress, pregnancy and acute phase reactions.
- ⚠Results should be interpreted by a haematologist in the context of clinical findings and additional coagulation assays.
Risks & Considerations
- ●Slight pain or burning during needle insertion
- ●Small bruise at the puncture site
- ●Bleeding from the site (rare, can be minimized with pressure)
- ●Infection (very rare when standard sterilisation is used)
Interfering Factors
- ●Heparin therapy within 24 hours before sample collection
- ●Oral anticoagulant therapy within 7 days before sample collection
- ●Improper blood-to-citrate ratio in the collection tube
- ●Haemolysed or clotted specimen
- ●Delayed sample processing and storage
Compare With Similar Tests
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Frequently Asked Questions
What is the Von Willebrand Factor Antigen (vWF Ag) test?
Why is the vWF Ag test done?
What symptoms may require a vWF Ag test?
What is the cost of the vWF Ag test in India?
What sample is required for this test?
Do I need to fast before a vWF Ag test?
Can medicines affect the vWF Ag test result?
How long does it take to get the report?
What does a low vWF Ag level mean?
Can a normal vWF Ag level exclude all bleeding disorders?
Is home sample collection available for this test?
Is the vWF Ag test covered by insurance or government schemes?
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