Natural Killer Cell Percentage in Blood (Qualitative)
This test measures the proportion of natural killer (NK) cells in your blood, which are a type of white blood cell that help fight infections and cancer.
["NK cells play a key role in immune defense; this test helps assess immune function and monitor conditions affecting white blood cells."]
Key facts at a glance
- LOINC
- 53759-7
- Short code
- Natural killer cell Pnl Bld FC
- Synonyms
- Natural killer cell Pnl Bld 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
- 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
What Are Natural Killer Cells?
Natural killer (NK) cells are a specialized type of white blood cell that help your body fight off viruses, bacteria, and abnormal cells like cancer. They work by recognizing and destroying cells that are infected or cancerous without needing prior sensitization, making them an important part of your immune system.
Why Might This Test Be Ordered?
Your healthcare provider may order this test if you have symptoms of immune system issues, such as frequent infections, unexplained fatigue, or if you’re undergoing treatment for conditions like cancer or autoimmune diseases. It can also be used to monitor immune function before or after certain therapies.
Sample Collection and Preparation
A small sample of your blood will be drawn from a vein, typically in your arm. The blood is then processed to separate and analyze the NK cells. This test is usually performed on whole blood and does not require fasting.
What Does a Positive or Abnormal Result Mean?
A qualitative result indicates whether NK cells are present in your blood sample. An abnormal result (either too high or too low) may suggest underlying immune dysfunction, certain cancers, or other conditions affecting white blood cell counts. Your healthcare provider will interpret the result in the context of your overall health and medical history.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
NK cell percentages can be useful in diagnosing or monitoring conditions such as immune deficiencies, certain cancers (e.g., lymphoma), or after treatments like chemotherapy or stem cell transplants. Low NK cell percentages may indicate weakened immune function, while high percentages could be seen in certain immune disorders or infections. Always discuss results with your provider for personalized insights.
Short name
NK Cell % (Qualitative)
Frequently asked questions
What does a qualitative NK cell percentage test tell me about my immune system?
How long does it take to get results from this test?
Can lifestyle factors, like diet or stress, affect NK cell percentages?
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