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DOCK8 Protein on Natural Killer (NK) Cells by Flow Cytometry

Published: August 9, 2026Updated: August 17, 2026

This test measures the level of DOCK8 protein found on the surface of natural killer (NK) cells in a sample of your blood, using a laboratory technique called flow cytometry to help your doctor evaluate how well your immune system is working.

Quick summary

{"This test examines NK cells (CD56+ cells) in your blood for DOCK8 protein","DOCK8 is important for proper immune system function","Abnormal results may indicate an immune deficiency or dysfunction","A blood sample is all that is needed for this test","Results help doctors evaluate immune system health"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
96418-9
Short code
NK-DOCK8-FC
Synonyms
NK Cells DOCK8+/NK Cells NFr Bld FC
Category
cardiac
Sample
whole-blood
Container
EDTA (lavender top) tube - 6 mL draw
Units
N/A
Ref low
85
Ref high
99
Critical range
5 N/A – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
0–100 years
Method
flow-cytometry
CPT
88188
SNOMED
708175002
Specimen volume
3-5 mL whole blood in EDTA tube
Stability
Room temperature: 24-48 hours; Refrigerated (2-8°C): up to 72 hours. Process within 24 hours for optimal results. Do not freeze.
Hemolysis max
50
Lipemia max
100
Icterus max
20
TAT
48–96 hours
Order
routine

What is the DOCK8 protein test for NK cells?

This test uses a laboratory method called flow cytometry to measure the amount of DOCK8 protein on your natural killer (NK) cells, which are a type of white blood cell. NK cells play a crucial role in your body's defense against viruses and cancer, and DOCK8 is a protein that helps these cells work properly.

Why might my doctor order this test?

Your doctor may order this test to evaluate how well your immune system is working. It can help diagnose conditions related to DOCK8 deficiency, which affects how well your immune cells fight infections. The results may also provide useful information about certain immune-related conditions that could have an impact on your heart health.

How is the DOCK8 flow cytometry test performed?

A healthcare professional will draw a small blood sample from a vein in your arm, usually on the inside of your elbow. The sample is then sent to a laboratory, where flow cytometry technology is used to analyze your NK cells and measure the amount of DOCK8 protein. The entire process feels similar to a routine blood draw.

Reference range

Reference range: DOCK8+ expression in CD3-CD14-CD45+CD56+ NK cells: 85-99% of parent population. Normal NK cell percentage of total lymphocytes: 5-27%. Clinical correlation required.N/A

Specimen: whole-blood

No special preparation required. Standard venipuncture procedure. Avoid excessive handling of sample. Inform laboratory if patient has recent infections or immunosuppressive therapy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Abnormal DOCK8 expression on NK cells may indicate an immune deficiency disorder. Low or absent DOCK8 can lead to increased susceptibility to viral infections, allergies, and certain autoimmune conditions. In some cases, immune system abnormalities may also relate to inflammatory conditions affecting the heart and blood vessels. This test helps healthcare providers assess the functional capacity of NK cells in your immune system.

Frequently asked questions

Do I need to fast before this test?
No, fasting is not required for this test. You can eat and drink normally beforehand, and you should continue taking your medications as usual unless your doctor gives you different instructions. Staying well hydrated before your appointment may also make the blood draw easier and more comfortable for you.
Are there any risks with this blood test?
The risks associated with this test are minimal and similar to those of any routine blood draw. You may experience slight pain, minor bruising, or a small amount of bleeding where the needle was inserted, but these symptoms usually go away quickly and rarely cause any serious problems.
How long does it take to get results?
Results are typically available within a few days to a week, although the exact timing can vary depending on the laboratory and testing volume. Once your results are ready, your doctor will review them with you and explain what the DOCK8 protein levels mean for your overall health.
What do abnormal DOCK8 test results mean?
Abnormal DOCK8 protein levels may suggest an immune system disorder, such as DOCK8 deficiency, but they do not provide a diagnosis on their own. Your doctor will interpret the results in the context of your symptoms, medical history, and overall health, and may recommend additional tests or a referral to an immune system specialist.
  1. 1
    LOINC Code InformationSource
  2. 2
    Flow Cytometry in Clinical DiagnosisSource
  3. 3
    DOCK8 ImmunodeficiencySource

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 17, 2026. · Read our editorial policy