Lysozyme, Serum
A serum lysozyme test measures the amount of lysozyme, an enzyme made mainly by certain white blood cells, in your blood. It can help support the evaluation of conditions such as sarcoidosis, tuberculosis, and some blood or kidney disorders.
["Serum lysozyme is a supportive blood test that is interpreted alongside your symptoms, other lab results, and imaging rather than on its own."]
Key facts at a glance
- LOINC
- 102420-7
- Short code
- Lysozyme IgE RAST
- Synonyms
- Lysozyme IgE RAST
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- rast
- CPT
- 84484
- SNOMED
- 302774002
- 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 Is Lysozyme?
Lysozyme is an enzyme found in many body fluids and tissues. It is produced in large amounts by some white blood cells, such as monocytes and macrophages, and is also present in tears, saliva, and other secretions. Because these cells are involved in inflammation and immune responses, the amount of lysozyme in the blood can change in certain diseases.
Why Might Your Doctor Order This Test?
Your doctor may order a serum lysozyme test when evaluating conditions associated with increased monocyte activity or granulomatous inflammation, such as sarcoidosis or tuberculosis. It may also be used as part of the work-up for certain blood disorders, kidney problems, or unexplained inflammatory symptoms. It is usually ordered together with other tests, not by itself.
How the Test Is Done
The test requires a blood sample, usually drawn from a vein in your arm. You may be asked about fasting or medications depending on your doctor's instructions, since some conditions and drugs can affect results. The sample is then sent to a laboratory for measurement.
What the Results Mean
Results are reported as a concentration of lysozyme in the blood. Levels can be higher or lower than usual in different conditions, and changes are not specific to any single disease. Your doctor will interpret the result in the context of your symptoms, physical exam, imaging, and other laboratory tests rather than using a single number to make a diagnosis.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Serum lysozyme can be elevated in conditions that increase monocyte or macrophage activity, including sarcoidosis, tuberculosis, and some hematologic disorders, and it may also be abnormal in certain kidney or inflammatory conditions. Because results overlap across many diseases and can be influenced by other factors, the test is used as supporting information and should always be interpreted with the full clinical picture.
Short name
Serum lysozyme
Frequently asked questions
Does an abnormal serum lysozyme result mean I have a specific disease?
Do I need to fast before a lysozyme blood test?
Can medications or other conditions affect my lysozyme level?
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 17, 2026. · Read our editorial policy