Factor VIII Assay Test: Booking, Price, and Results
About Factor VIII Assay Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | Factor VIII Activity Test, Antihemophilic Factor (AHF) Assay, Plasma Factor VIII Antigen Test, FVIII Activity |
| Sample Type | Venous blood (citrated plasma) |
| Fasting Required | No fasting required |
| Report Time | Within 4 hours |
| Recommended For | All genders and ages; primarily used for diagnosing bleeding disorders |
| Price | Starting at ₹900 |
What Is a Factor VIII Assay Test?
The Factor VIII assay test measures the activity of Factor VIII, a protein essential for normal blood clotting. It is part of the intrinsic coagulation pathway and circulates in plasma bound to von Willebrand factor. Low levels can cause a bleeding disorder called Haemophilia A, so this test helps detect it early for proper treatment. Doctors order this test to investigate unexplained bleeding, diagnose inherited clotting disorders, or monitor ongoing treatment. It is also called the antihemophilic factor (AHF) test or Factor VIII activity test.
What Does a Factor VIII Assay Test Measure?
This test evaluates the functional activity of Factor VIII in the blood. Normal haemostasis requires at least 25% of Factor VIII activity to be present. The table below summarises what is assessed.
| Parameter | What It Tells You |
|---|---|
| Factor VIII Activity | How well Factor VIII is functioning in the clotting process, expressed as a percentage of a normal reference value |
The plasma Factor VIII antigen test and Factor VIII clotting assay methods may both be used, depending on the clinical question. The biological half-life of Factor VIII is around 9 to 18 hours, so levels can shift relatively quickly.
Why Is a Factor VIII Assay Test Done?
A doctor may order this test for several reasons, ranging from investigating a bleeding symptom to tracking a known condition.
Common Symptoms That May Require This Test
The following symptoms are common reasons a doctor may request a Factor VIII activity test:
- Prolonged or excessive bleeding after a minor cut or surgical procedure
- Easy or unexplained bruising
- Frequent, unprovoked nosebleeds
- Heavy menstrual bleeding
- Joint pain or swelling without a clear cause
- Blood in urine or stools
- Unexplained bleeding into vital organs (e.g. gastrointestinal tract)
- Severe low back pain, usually limited to one side
- Blood transfusion after a minor injury
Conditions This Test Can Help Detect
This test can help identify several bleeding-related conditions, including:
- Haemophilia A, an inherited disorder caused by a deficiency or absence of Factor VIII
- Von Willebrand disease, when assessed alongside von Willebrand factor antigen and activity
- Acquired Factor VIII deficiency linked to autoimmune conditions, lymphoproliferative disorders, or disseminated intravascular coagulation (DIC)
- Prolonged activated partial thromboplastin time (aPTT), which may point to a clotting factor problem
Factor VIII Assay Test for Chronic Disease Monitoring
For people diagnosed with haemophilia A, managing Factor VIII levels is an ongoing process. Because both excess and insufficient clotting factor carry serious risks, regular monitoring is essential. The Factor VIII clotting assay is used before and after factor replacement infusions and to guide decisions about preventive therapy frequency.
How to Prepare and What to Expect
Preparation for this test is straightforward, though a few important steps help ensure an accurate result.
Do You Need to Fast?
No fasting is required before the Factor VIII assay test. If you are on anticoagulants such as warfarin or heparin, or on fibrinolytic agents, discuss timing with your doctor before the test. Where medically possible, intravenous heparin should be withheld for 4 to 6 hours before the sample is collected, and subcutaneous heparin or warfarin for 10 to 14 days beforehand.
Practical Tips Before Your Test
Keep the following in mind before your appointment:
- Tell your doctor about all medications you are taking, especially blood thinners or anticoagulants
- Mention any recent illness, stress, or significant physical activity, as these can affect coagulation
- Wear a short-sleeved or loose-sleeved top to make the blood draw easier
- Stay well hydrated, as this helps the phlebotomist locate a vein more easily
- Avoid strenuous exercise on the day of your test
Step-by-Step Procedure
Here is what to expect when your sample is collected:
- A trained phlebotomist cleans a site on your arm with an antiseptic solution.
- A tourniquet is briefly applied to make the vein easier to locate.
- A small needle is used to draw blood into a light-blue tube that contains sodium citrate, which prevents premature clotting.
- The tube is gently inverted at least six times immediately after collection to mix the sample properly.
- The tourniquet is removed, a small dressing is applied to the puncture site, and you are free to leave.
- The sample is sent to the laboratory promptly, as Factor VIII is a time-sensitive protein.
Factors That Can Affect Accuracy
Several factors can interfere with the accuracy of this test:
- Improper handling or delayed processing of the sample
- Prolonged tourniquet time, which may artificially raise Factor VIII levels
- Sample haemolysis (breakdown of red blood cells) or a clotted sample
- Underfilled collection tubes
- Certain medications, including argatroban, heparin, and hirudin
- Presence of lupus anticoagulant, which may cause Factor VIII levels to appear lower than they are
Understanding Your Factor VIII Assay Test Results
Results from a Factor VIII activity test need to be read alongside your full clinical picture. A doctor will consider your symptoms, personal history, and any other test findings before concluding.
| Parameter | Normal Range | Low (May Indicate) | High (May Indicate) |
|---|---|---|---|
| Factor VIII Activity | 50% to 200% of the reference value | Below 50%: possible haemophilia A; below 1%: severe haemophilia A | Liver disease, oestrogen therapy, inflammatory conditions, increased clotting risk |
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Factor VIII levels can shift in certain situations that are worth being aware of:
- During pregnancy, Factor VIII and von Willebrand factor levels rise gradually and peak shortly before delivery. In women with von Willebrand disease, this increase is much less pronounced.
- Acquired haemophilia, caused by autoantibodies against Factor VIII, can develop after childbirth or in older individuals with autoimmune conditions.
- The presence of lupus anticoagulant may cause the test to underestimate the true Factor VIII level.
How to Maintain Healthy Levels
While Factor VIII levels are largely determined by genetics or underlying disease, the following general habits support overall well-being:
- Attend regular follow-up appointments at a haemophilia treatment centre if you have a diagnosed bleeding disorder.
- Avoid activities with a high injury risk if your Factor VIII levels are known to be low.
- Keep an updated record of your Factor VIII levels and share it with all treating doctors.
Lupin Diagnostics Factor VIII Assay Test Price and Home Collection
The Factor VIII assay test starts at approximately ₹900 at Lupin Diagnostics, with home sample collection available across major Indian cities.
| City | Approximate Price (₹) |
|---|---|
| Mumbai | ₹900 |
| Bangalore | ₹900 |
| Bhopal | ₹900 |
| Hyderabad | ₹900 |
| Chennai | ₹900 |
| Kolkata | ₹900 |
| Pune | ₹900 |
| Nagpur | ₹900 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps to book your test:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred time slot.
- Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Home Collection
Lupin Diagnostics offers home sample collection for the plasma Factor VIII antigen test across cities in India. All samples are processed in NABL-accredited laboratories by experienced technologists. Your digital report is delivered directly to your email or WhatsApp, making the process convenient and reliable.
Frequently Asked Questions
The Factor VIII activity test is primarily used to diagnose haemophilia A and other bleeding disorders related to clotting factor deficiency. It also helps monitor how well factor replacement therapy is working in people already diagnosed with haemophilia A or von Willebrand disease.
No, fasting is not required. You can eat and drink as usual before your appointment. However, tell your doctor about any medications you are taking, especially blood thinners, as these may need to be paused before the test.
A small amount of blood is drawn from a vein in your arm into a blue-top tube containing sodium citrate. The sample is then gently mixed and sent to the laboratory quickly, as Factor VIII is a fragile protein that can degrade if not handled promptly.
A result below 50% of the normal reference value may suggest haemophilia A, a genetic condition caused by missing or defective Factor VIII. Low levels can also indicate von Willebrand disease or an acquired Factor VIII deficiency caused by an autoimmune response.
Haemophilia A is predominantly seen in men because it is X-linked. However, female carriers can sometimes have reduced Factor VIII levels and experience mild to moderate bleeding symptoms. The Factor VIII clotting assay is useful in identifying such cases.
Yes. Factor VIII levels rise gradually during a healthy pregnancy, peaking just before delivery. Women with von Willebrand disease may not show this expected rise, which can increase their bleeding risk around childbirth.
Testing frequency depends on the severity of the condition and the treatment plan. Patients on regular prophylactic therapy may need monitoring before and after factor infusions. Many patients with stable haemophilia see their specialist team annually, though those with severe disease or changes in therapy are tested more frequently.
Factor VIII Assay Test: Booking, Price, and Results
