T-cell subset count: CD4+ T-lymphocytes (serum/plasma)
This test measures the number of CD4+ T cells in your blood, a key immune cell type that helps fight infections and regulates immune responses. CD4+ cells are often monitored in people with weakened immune systems.
["CD4+ T-cell counts help track immune health, especially in conditions like HIV or cancer treatments."]
Key facts at a glance
- LOINC
- 107069-7
- Short code
- TdT Cells NFr Mar FC
- Synonyms
- TdT Cells NFr Mar FC
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- CPT
- 86430
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters for Your Health
CD4+ T cells are a critical part of your immune system. They play a vital role in identifying and attacking pathogens like viruses, bacteria, and fungi. Low levels of CD4+ cells can indicate an impaired immune response, which may increase your risk of infections or other health complications. This test is often used to monitor immune function, especially in people with chronic illnesses or undergoing treatments that affect immunity.
What to Expect Before the Test
No special preparation is needed for this test. You may have a blood draw at a clinic, hospital, or lab. The process is quick and typically done while you sit comfortably. If you’re taking medications that could affect immune cells, let your healthcare provider know before the test.
What the Results Mean
Your results will show the number of CD4+ T cells in your blood sample. While specific reference ranges can vary by lab, lower counts may suggest immune suppression, while higher counts may indicate normal or overactive immune activity. Your healthcare provider will interpret the results in the context of your overall health and medical history.
Common Reasons for This Test
Doctors may order this test to evaluate immune function, monitor conditions like HIV/AIDS, track responses to treatments (such as chemotherapy or steroids), or assess risks for infections in people with weakened immune systems.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CD4+ T-cell counts are essential for diagnosing and managing immune-related conditions. In HIV infection, for example, lower CD4+ counts correlate with disease progression and higher risk of infections or opportunistic illnesses. Regular monitoring helps guide treatment decisions and ensures timely interventions to maintain immune health.
Short name
CD4+ T-cell count
Frequently asked questions
How long does it take to get my test results?
Can I eat or drink before this test?
What if my CD4+ count is lower than expected?
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