Omalizumab (Anti-IgE Antibody) Level, Serum
This test measures the amount of a specific antibody (IgE) in your blood that binds to a protein called omalizumab, used in certain allergy treatments.
["This test helps monitor how your body responds to omalizumab therapy for allergic conditions."]
Key facts at a glance
- LOINC
- 36776-3
- Short code
- XR tomo Mastoid
- Synonyms
- XR tomo Mastoid
- 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
- xr-tomography
- 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 Does This Test Measure?
Omalizumab is a medication designed to bind to IgE antibodies, which are linked to allergic reactions. This test checks the concentration of omalizumab in your serum to ensure it’s working at the right level in your bloodstream. It’s typically done to verify therapeutic effectiveness or adjust dosing if needed.
Why Might You Need This Test?
Your healthcare provider may order this test if you’re receiving omalizumab treatment for conditions like severe asthma or allergic rhinitis. It helps track whether the medication is providing the expected benefits and if your levels are within the target range for safety and effectiveness.
How Is the Test Done?
A small blood sample is drawn from a vein, usually in your arm. The blood is then sent to a lab for analysis. The test measures the amount of omalizumab protein in your serum, which is the liquid part of your blood after blood cells and clotting factors are removed.
What Are Possible Results?
Results are typically reported as a concentration value (e.g., in micrograms per milliliter). Your healthcare provider will interpret these results in the context of your treatment plan and medical history to determine if your levels are appropriate.
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.
◆Associated findings1
Short name
IgE Antibody Test
Frequently asked questions
How often should I expect this test?
If your omalizumab levels are too low, your doctor may adjust your dosage to ensure you’re receiving the correct amount for effective treatment. If levels are too high, it may indicate an issue with absorption or dosing, which could require further evaluation.
You can typically eat and drink normally before this test unless your doctor specifies otherwise. No special preparation is usually needed, but follow any instructions provided by your healthcare provider or lab technician.
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