Intrinsic Factor IgG Antibody Test: Booking, Price, and Results
About Intrinsic Factor IgG Antibody Test
| Field | Value |
|---|---|
| Also Known As | IF Antibody Test, Intrinsic Factor Blocking Antibody (IFBA) Test, Anti-Intrinsic Factor Test, Intrinsic Factor Binding Antibody Test |
| Sample Type | Serum (venous blood) |
| Fasting Required | No fasting required |
| Report Time | 4 days |
| Recommended For | Adults of all ages; particularly those over 60 with suspected vitamin B12 deficiency or pernicious anaemia |
| Price | Starting at ₹1,400 |
What Is an Intrinsic Factor IgG Antibody Test?
The intrinsic factor IgG antibody test is a blood test that detects specific antibodies produced by the immune system against intrinsic factor, a protein made in the stomach that is essential for vitamin B12 absorption. Doctors typically prescribe this test when a patient shows signs of vitamin B12 deficiency or suspected pernicious anaemia, an autoimmune condition. A small blood sample is drawn from a vein, and the serum is analysed using EIA (enzyme immunoassay) technology. It is also known as the IF antibody test, intrinsic factor blocking antibody (IFBA) test, anti-intrinsic factor test, or intrinsic factor binding antibody test.
What Does an Intrinsic Factor IgG Antibody Test Measure?
This test looks for two types of IgG antibodies that target intrinsic factor. Both types interfere with the body's ability to absorb vitamin B12 through different mechanisms. The table below outlines the two antibody types detected:
| Antibody Type | What It Does |
|---|---|
| Type 1 (Blocking Antibody) | Blocks the site on intrinsic factor where vitamin B12 binds; more specific for pernicious anaemia and the type most commonly tested |
| Type 2 (Binding Antibody) | Attaches to the vitamin B12-intrinsic factor complex and prevents its uptake in the small intestine |
Why Is an Intrinsic Factor IgG Antibody Test Done?
Doctors order this test to investigate unexplained vitamin B12 deficiency or to confirm whether an autoimmune process is responsible. Below are the key reasons it may be requested.
Common Symptoms That May Require This Test
Your doctor may recommend this test if you are experiencing any of the following:
- Persistent fatigue and unexplained weakness
- Numbness or tingling in the hands and feet
- Pale skin or mild yellowing of the eyes or skin
- Swollen, red tongue or bleeding gums
- Lightheadedness when standing up or during physical activity
- Loss of appetite or changes in bowel habits
- Shortness of breath during exercise
Conditions This Test Can Help Detect
This test can support the diagnosis of several conditions. These include:
- Pernicious anaemia, an autoimmune condition where the immune system destroys intrinsic factor, leading to vitamin B12 deficiency and abnormally large red blood cells (megaloblastic anaemia)
- Autoimmune gastritis, a condition affecting the stomach lining
- Associated autoimmune conditions, including Hashimoto's thyroiditis, type 1 diabetes mellitus, Grave's disease, rheumatoid arthritis, and myasthenia gravis
How to Prepare and What to Expect
No special preparation is needed for the intrinsic factor IgG antibody test, but a few steps will help ensure an accurate result.
Do You Need to Fast?
No, fasting is not required before this test. You can eat and drink normally on the day of your appointment. However, if additional tests have been ordered at the same time, some of those may require fasting, so check with your doctor.
Practical Tips Before Your Test
Keep the following points in mind before your sample is collected:
- Bring a detailed clinical history including your symptoms, previous test results, and any relevant medical records, as this is required for the test.
- Do not have a vitamin B12 injection or radiolabelled vitamin B12 injection within the two weeks before this test, as this can interfere with results.
- Inform your doctor about all medications and supplements you are currently taking.
- Stay well hydrated, as this makes blood collection easier.
- Wear clothing with loose or roll-up sleeves for easy access to your arm.
Step-by-Step Procedure
Here is what to expect during the intrinsic factor IgG antibody test procedure:
- A trained phlebotomist will clean the skin on your inner elbow or back of the hand with an antiseptic solution.
- An elastic band is placed around the upper arm to make the veins more visible and accessible.
- A sterile needle is gently inserted into a vein, and approximately 3 ml of blood is drawn into a gold-top SST gel tube.
- The needle is removed, and a cotton pad or small bandage is placed over the puncture site to stop any bleeding.
- The entire blood draw takes around 5 to 10 minutes and is generally well tolerated.
- The sample is refrigerated and sent to the NABL-accredited Lupin Diagnostics laboratory for analysis using the EIA method.
Factors That Can Affect Accuracy
Several factors may influence your results. Be aware of the following:
- Recent vitamin B12 injections (within two weeks) can directly interfere with test accuracy.
- Certain medications and supplements, including high-dose vitamin B12 tablets, may affect antibody detection.
- Improper sample storage or delays in transport can affect the quality of the serum.
- Having other autoimmune conditions (such as rheumatoid arthritis or autoimmune thyroid disease) may produce a positive result without a diagnosis of pernicious anaemia.
Understanding Your Intrinsic Factor IgG Antibody Test Results
Your doctor will review your results alongside your symptoms, medical history, and other test findings. The table below shows the general reference ranges used for this test:
| Result | Range (AU/mL) | Interpretation |
|---|---|---|
| Negative | Less than 1.20 | Intrinsic factor antibodies not detected |
| Equivocal | 1.21 to 1.52 | Borderline; further testing may be recommended |
| Positive | Greater than 1.53 | Intrinsic factor antibodies detected |
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
Certain conditions can affect how your results are interpreted:
- Patients with autoimmune conditions such as rheumatoid arthritis or autoimmune thyroid disease may test positive without having pernicious anaemia. A positive result alone is not a diagnosis.
- A negative result does not rule out pernicious anaemia. Intrinsic factor antibodies are found in only around 70% of pernicious anaemia cases, so further tests may still be required.
- Anti-intrinsic factor antibodies can sometimes interfere with vitamin B12 blood tests, causing falsely elevated B12 readings and masking a true deficiency.
How to Maintain Healthy Levels
The following general wellness habits support adequate vitamin B12 status:
- Include vitamin B12-rich foods in your diet, such as meat, fish, eggs, and dairy products, if you do not have an absorption problem.
- Attend regular health check-ups to monitor your vitamin B12 levels and blood counts, particularly if you are over 60.
- Discuss any concerns about supplements or dietary changes with your doctor before making adjustments.
Lupin Diagnostics Intrinsic Factor IgG Antibody Test Price and Home Collection
The intrinsic factor IgG antibody test cost at Lupin Diagnostics starts at ₹1,400, and home collection is available across cities in India. City-wise indicative prices are listed below.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 1400 |
| CHENNAI | 1400 |
| HYDERABAD | 1400 |
| KOLKATA | 1400 |
| NAVI MUMBAI | 1400 |
| PUNE | 1400 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps for intrinsic factor IgG antibody test online booking:
- 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 4 days.
Home Collection
Intrinsic factor IgG antibody test home collection is available across cities through Lupin Diagnostics. A certified phlebotomist will visit your home at your chosen time to collect the blood sample. All samples are processed in NABL-accredited laboratories, and your digital report is shared via email or WhatsApp once ready.
Frequently Asked Questions
This test detects IgG antibodies directed against intrinsic factor, a protein required for vitamin B12 absorption in the gut. It is primarily used to confirm pernicious anaemia as the cause of vitamin B12 deficiency. Your doctor may order it alongside a serum B12 test or a complete blood count.
No fasting is required. You can have your normal meals and drinks before the test. If other tests are ordered at the same appointment, check with your doctor whether any of those require fasting.
Yes. Intrinsic factor antibodies are found in only around 70% of pernicious anaemia cases, so a negative result does not rule out the condition. Your doctor may recommend additional tests, such as gastric parietal cell antibodies, if pernicious anaemia is still suspected.
This intrinsic factor IgG antibody test should not be taken within two weeks of receiving a vitamin B12 or radiolabelled vitamin B12 injection. Doing so may interfere with the accuracy of the result. Inform your doctor about any recent injections so the test can be scheduled at the right time.
The procedure involves a standard venous blood draw and is generally safe. You may feel mild discomfort, slight bruising, or temporary swelling at the puncture site, which resolves on its own within a day or two.
Anyone experiencing persistent fatigue, numbness in the hands or feet, unexplained anaemia, or symptoms linked to autoimmune conditions affecting the stomach should speak to their doctor about the intrinsic factor IgG antibody test. People over 60 are at higher risk for pernicious anaemia and may benefit from early testing.
Intrinsic Factor IgG Antibody Test: Booking, Price, and Results
