Skip to content

Absolute Count of CD4+ T Lymphocytes (from Whole Blood)

Published: August 9, 2026Updated: August 16, 2026

This test measures the number of a specific type of white blood cell called CD4+ T lymphocytes, which play a key role in the immune system.

Quick summary

["CD4+ T cells help your body fight infections and are often monitored in conditions like HIV."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
8103-4
Short code
CD45CD14
Synonyms
CD45+CD14+ Cells NFr Bld
Category
chemistry
Sample
whole-blood
Container
EDTA (lavender-top) tube, ACD (yellow-top) tube, or heparinized tube validated for flow cytometry
Units
N/A
Ref low
200
Ref high
700
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Flow cytometry using fluorescently labeled monoclonal antibodies against CD45 (leukocyte common antigen) and CD14 (lipopolysaccharide co-receptor, monocyte marker)
CPT
86359
SNOMED
122548005
Specimen volume
3-5 mL whole blood; minimum 1 mL for pediatric samples
Stability
Specimen should be processed within 24-48 hours of collection when stored at room temperature (18-25°C). Refrigeration may affect cell viability and should be avoided unless specifically validated. Do not freeze.
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Matters

CD4+ T cells are a critical part of your immune system. They help your body recognize and fight off infections, including viruses like HIV. This test helps doctors monitor your immune health, especially if you have a condition that affects your immune system.

What to Expect Before the Test

No special preparation is needed for this test. You may have a small needle inserted into your arm or vein to draw a blood sample. The process is quick and usually painless. You can eat and drink normally before the test.

What the Results Mean

The results show the number of CD4+ T cells in your blood. Lower counts may indicate weakened immunity, which can be seen in certain diseases or immune disorders. Your doctor will interpret the results in the context of your overall health and medical history.

Common Reasons for Testing

This test is often performed in people with HIV to track immune function, monitor treatment progress, or assess the need for additional care. It may also be used in other conditions where immune health is a concern, such as certain cancers or autoimmune diseases.

Reference range

Reference ranges vary by laboratory and instrumentation. Typical adult values for CD45+CD14+ monocytes are approximately 200-700 cells/μL (2-10% of total leukocytes). Percentages of total leukocytes typically range from 2-12%. Results should be interpreted using the reference interval provided by the performing laboratory.N/A

Specimen: whole-blood

No fasting required. Specimen should be collected by standard venipuncture technique into anticoagulant-containing tube. Patient should be in steady state; avoid specimen collection during acute illness or immediately after strenuous exercise when possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CD4+ T Cell Count

Frequently asked questions

What does a low CD4+ T cell count mean?
A low CD4+ T cell count can signal a weakened immune system. In the context of HIV, it often correlates with disease progression and may indicate the need for adjustments in treatment or closer monitoring. Your doctor will discuss the results with you and determine the next steps based on your health status.
How often should I get this test?
The frequency of testing depends on your medical condition and treatment plan. If you have HIV, your doctor may recommend regular testing to monitor your immune health. Follow your healthcare provider’s instructions for scheduling.
Can I eat or drink anything before this test?
Yes, you can eat and drink normally before this test. No special diet or fasting is required.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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