IgG4 subclass blood test
Quick answer: This test measures IgG4, one subclass of the IgG antibody, in your blood. Doctors order it when they suspect IgG4-related disease, which causes swelling of organs such as the pancreas or salivary glands.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
How the test is done
- 1You sit and the skin over a vein is cleaned
- 2A needle draws blood into a tube
- 3The lab measures IgG4
- 4Your doctor reads it with scans and sometimes a biopsy
What your results can mean
Reading your report
Raised IgG4 is not specific on its own, so discuss your result with your doctor.
If the result is outside the usual range
A high level can be seen with IgG4-related disease, which can cause swelling of the pancreas, bile ducts, salivary glands or other organs. Some people with the disease have normal levels, and allergies can raise it a little.
Who usually has this test
People with unexplained swelling of organs such as the pancreas, salivary glands or tear glands, or suspected IgG4-related disease.
Risks and aftercare
Watch for a bruise at the needle site; nothing else is needed.
Names and options
Also called: IgG4
Listed by the hospital as
- IMMUNOGLOBULIN SUBCLASSES IGG4, SERUM
Questions about this test
What is IgG4-related disease?
It is a condition in which immune cells cause swelling and scarring in organs such as the pancreas, bile ducts or glands. It often responds to treatment.
Does a high IgG4 confirm the disease?
Not by itself. A biopsy and scans are usually needed to confirm it.
Why is IgG4 checked with CA 19-9 sometimes?
IgG4-related disease of the pancreas can look like pancreatic cancer on scans. Doctors use several tests to tell them apart.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
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This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.