CD4 T-Cell Count (Absolute)
This test measures the number of CD4 cells (a type of white blood cell) in your blood. CD4 cells help the immune system fight infections.
["CD4 cells are key to your immune health; lower counts may signal immune weakness."]
Key facts at a glance
- LOINC
- 81755-1
- Short code
- LPT IL-2 max/CD45 NFr Bld FC
- Synonyms
- LPT IL-2 max/CD45 NFr Bld FC
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order a CD4 count to monitor your immune system, especially if you have HIV, an autoimmune condition, or are undergoing treatments that affect immunity. It can also help track how well your immune system is responding to treatment or disease progression.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood, similar to a routine blood draw. The process usually takes a few minutes.
What the Results Mean
Results are typically reported as a count of CD4 cells per microliter (cells/µL) of blood. While specific ranges vary by lab, lower counts often indicate a weakened immune system, which can increase risk for infections.
Common Conditions Monitored
A CD4 count is often used to diagnose and manage HIV/AIDS, track immune recovery in cancer treatments, or evaluate conditions like lupus or other autoimmune diseases.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: CD4 counts are critical for assessing immune function. Very low counts (often below 200 cells/µL) may indicate severe immune deficiency, increasing vulnerability to infections or cancers. Regular monitoring helps guide treatment decisions.
Short name
CD4 Count
Frequently asked questions
What does a low CD4 count mean?
How often should I get this test?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy