IgG4 Subclass Test: Booking, Price, and Results
About IgG4 Subclass Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | IgG4, Immunoglobulin G subclass 4, IgG subclass 4 |
| Sample Type | Serum (venous blood) |
| Fasting Required | Preferred but not required (12 hours if fasting) |
| Report Time | 5 Days |
| Recommended For | Male, Female (all ages; results in children under 10 require careful interpretation) |
| Price | Starting at ₹7,300 |
What is an IgG4 Subclass Test?
The IgG4 subclass test measures the level of Immunoglobulin G Subclass 4 (IgG4) in your blood. IgG4 is one of four subtypes of IgG, the most common antibody in the human body. Doctors order this test when they suspect an immune-related condition, particularly IgG4-related disease. It is also known as Immunoglobulin G subclass 4 or simply IgG4. A small serum sample drawn from a vein in your arm is used for this test.
What Does an IgG4 Subclass Test Measure?
This test measures the concentration of a single antibody subclass, IgG4, in your blood serum. IgG4 normally makes up only about 4% of the total IgG in the body. Unlike the other IgG subclasses, it has a low ability to activate the immune system's inflammatory response, giving it a relatively anti-inflammatory character.
Here is a brief overview of what the result reflects:
| Parameter | What it Tells You |
|---|---|
| Serum IgG4 Level | The concentration of IgG4 antibody in your blood, used to assess immune activity and detect related disorders |
Why is an IgG4 Subclass Test Done?
Doctors request this test when a patient shows signs that suggest either an overactive immune response linked to IgG4 or a possible antibody deficiency.
Common Symptoms That May Require This Test
The following symptoms may prompt a doctor to order an IgG4 subclass test:
- Unexplained swelling in an organ or body part
- Abdominal pain or jaundice (yellowing of the skin or eyes)
- Persistent cough or breathing difficulties
- Swollen salivary or tear glands
- Recurrent sinus, ear, or respiratory infections
- Fatigue accompanied by joint pain
Conditions This Test Can Help Detect
This test can assist in identifying or evaluating several conditions. These include:
- IgG4-related disease (IgG4-RD), a long-term inflammatory condition that can affect the pancreas, kidneys, salivary glands, eye area, and other organs
- Autoimmune pancreatitis and sclerosing cholangitis (scarring of the bile ducts)
- IgG subclass deficiency, which may cause recurrent infections
- Multicentric Castleman disease, Churg-Strauss syndrome, and sarcoidosis
IgG4 Subclass Test for Chronic Disease Monitoring
If you have already been diagnosed with IgG4-related disease, your doctor may repeat this test every three to six months. This helps track whether treatment is working or whether the condition has returned after a period of remission. Monitoring IgG4 levels over time is a useful part of managing this condition alongside clinical assessment and imaging.
How to Prepare and What to Expect
Preparing for this test is straightforward. The steps below will help you have a smooth experience.
Do You Need to Fast?
Fasting is preferred but not required before the IgG4 subclass test. If you choose to fast, 12 hours is recommended. You may drink water normally. If other tests have been ordered at the same time, check with your doctor whether fasting is needed for those.
Practical Tips Before Your Test
The following tips will help you prepare well:
- Stay well hydrated before sample collection
- Wear a loose top or a garment with sleeves that can be rolled up easily
- Tell your doctor about all medicines you currently take, including antihistamines, oral steroids, and immunosuppressants, as these can affect results
- Mention any known immune-related conditions, recent infections, or relevant medical history to your doctor before the test
Step-by-Step Procedure
- A trained phlebotomist cleans the skin on your inner arm with an antiseptic solution.
- A fine needle is used to draw a small blood sample (approximately 3 ml) from a vein in your arm.
- The blood is collected into a plain red-top tube with no additive.
- The sample is processed to separate the serum, which is the liquid part of your blood.
- The serum is stored under refrigeration and dispatched to the laboratory for analysis using an EIA (enzyme immunoassay) method.
- Your report is typically ready within 5 days.
Factors That Can Affect Accuracy
Certain factors may influence your results. Be aware of the following:
- Haemolysis (broken red blood cells in the sample) can interfere with the test
- The presence of abnormal proteins (paraproteins) or a high fat content (lipaemia) in the blood may affect readings
- Medications that alter immune function, such as steroids or immunosuppressants
- Recent infections, which can temporarily raise antibody levels
- Dehydration at the time of blood draw
Understanding Your IgG4 Subclass Test Results
Your results show the concentration of IgG4 in your blood serum. A qualified doctor should always review these results in the context of your symptoms, other test findings, and medical history.
| Parameter | Normal Range | Unit |
|---|---|---|
| Serum IgG4 (Adults) | Less than 135 | mg/dL |
| Serum IgG4 (Adults, alternate reference) | 5 to 154 | mg/dL |
| Serum IgG4 (Adults, g/L) | 0.05 to 1.35 | g/L |
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
Some individual and clinical factors can influence how results are interpreted:
- IgG4 concentrations are generally higher in males than in females and tend to decrease with age. This should be considered when interpreting results.
- In children under 10 years of age, IgG4 does not yet reach adult levels. A diagnosis of IgG4 deficiency should not be made in this age group.
- Patients with a history of allergic conditions, such as asthma or sinusitis, may have elevated IgG4 levels without an underlying IgG4-related disease.
- Certain medicines can raise or lower IgG4 levels, so medication history is important during interpretation.
How to Maintain Healthy Levels
These general wellness tips support overall immune function:
- Follow a balanced diet that includes a variety of fruits, vegetables, whole grains, and proteins
- Manage known allergies and chronic immune conditions under regular medical supervision
- Attend follow-up appointments as advised if you have a diagnosed immune-related condition
Lupin Diagnostics IgG4 Subclass Test Price and Home Collection
The IgG4 subclass test cost at Lupin Diagnostics starts at ₹7,300, and home collection is available across multiple cities in India. The table below lists cities where the test is offered.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 7300 |
| CHENNAI | 7300 |
| HYDERABAD | 7300 |
| KOLKATA | 7300 |
| NAVI MUMBAI | 7300 |
| PUNE | 7300 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
You can book the IgG4 subclass test online by following these steps:
- 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
IgG4 subclass test home collection is available across cities through Lupin Diagnostics. A certified phlebotomist visits your home to collect the serum sample, which is then processed in an NABL-accredited laboratory. Your digital report is delivered within 5 days via email or WhatsApp.
Frequently Asked Questions
The IgG4 subclass test is primarily used to support the diagnosis of IgG4-related disease, a chronic inflammatory condition that can affect multiple organs. It is also used to assess possible IgG subclass deficiency in patients with recurrent infections. The test measures the level of IgG4 antibody in your blood serum.
Fasting is preferred but not compulsory. If you choose to fast, 12 hours is recommended. You can continue drinking water as usual. If your doctor has ordered additional tests alongside this one, check whether fasting is needed for those separately.
A raised IgG4 level can point to IgG4-related disease, but it is not diagnostic on its own. High levels may also be seen in allergic disorders, autoimmune pancreatitis, Churg-Strauss syndrome, and sarcoidosis. Your doctor will consider the result alongside your symptoms, imaging, and other tests before drawing any conclusions.
Yes, children can have this test. However, IgG4 levels do not reach adult values until the age of 10, so a diagnosis of IgG4 deficiency should not be made in younger children based on this test alone. A specialist will interpret results in children with additional care.
For initial evaluation, the test is typically done once. If IgG4-related disease is confirmed, your doctor may request the test every three to six months to monitor how well treatment is working or to check for signs of relapse.
Yes, several medicines can influence IgG4 levels. Steroids and immunosuppressants are particularly known to affect antibody concentrations. Always tell your doctor about all medicines and supplements you are taking before the test so that results can be interpreted accurately.
No. A positive or elevated result supports the possibility of IgG4-related disease but does not confirm it on its own. Diagnosis requires a combination of blood test findings, clinical assessment, imaging, and in many cases, a tissue biopsy. Your doctor will use all available information together to arrive at a diagnosis.
IgG4 Subclass Test: Booking, Price, and Results
