White Blood Cell Clumping (Leukocyte Aggregation) Screening by Automated Fluid Analysis
This test checks for abnormal clumping of white blood cells in a blood sample, which may indicate certain immune system conditions or infections.
["Clumping of white blood cells can sometimes signal underlying health concerns that need further evaluation."]
Key facts at a glance
- LOINC
- 99933-4
- Short code
- WBC clumps Fld Ql Auto
- Synonyms
- WBC clumps Fld Ql Auto
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- automated
- CPT
- 85004
- SNOMED
- 900000000000003002
- 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 Might Be Ordered
Your healthcare provider may order this test if you have symptoms like frequent infections, unexplained fevers, or signs of an overactive immune response. It can also be part of routine blood work to monitor conditions like autoimmune diseases or chronic infections.
What to Expect During the Test
You’ll have a small needle inserted into your arm to draw blood. The blood sample is then analyzed automatically to detect any abnormal clumping of white blood cells. The process usually takes a few minutes, and you may feel a brief pinch or discomfort.
How the Results Are Interpreted
Results are typically qualitative (yes/no) or semi-quantitative, indicating whether clumping is present or not. Abnormal findings may prompt further testing or evaluation by your doctor.
Common Reasons for Abnormal Findings
Clumping of white blood cells can occur due to infections, certain medications, or conditions affecting the immune system. It may also be related to laboratory artifacts or specific blood disorders.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
WBC Clumping Screen
Frequently asked questions
What does a positive result mean?
Can lifestyle changes affect this test?
How soon will I get my results?
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