CD19 test
Quick answer: A CD19 test counts B cells, a type of white blood cell that makes antibodies. Doctors order it to check immune function or to monitor treatments that lower B cells.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
How the test is done
- 1Ask the hospital what the test is for and whether any preparation is needed
- 2A needle draws blood from a vein in your arm
- 3The sample is kept at room temperature and sent to the lab
- 4Your doctor explains the result in the context of your health
What your results can mean
Reading your report
Discuss your result with your doctor.
If the result is outside the usual range
A result outside the usual range can mean there are more or fewer B cells than expected. What this means depends on why the test was ordered, so ask your doctor or the hospital.
Who usually has this test
People whose doctor has asked for a B cell count; ask the hospital or your doctor what it is for in your case.
Risks and aftercare
You may have a small bruise; ask the hospital if any other care is needed.
Names and options
Also called: CD19 count, B cell count
Listed by the hospital as
- CD19, EDTA PLASMA
Questions about this test
What does a CD19 count measure?
It counts B cells, white blood cells that make antibodies. Ask your doctor why it has been requested for you.
Is a CD19 test done with other tests?
It is often part of a wider white cell or immune panel. Ask the hospital what is included in your test.
Who should explain my CD19 result?
The doctor who ordered it, as the meaning depends on your condition and any treatment you are having.
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
Waiting area
IVF lab
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.